There are 2782 circuit schematics available. The Last circuit was added on Saturday, January 28, 2023.Please note some adblockers will suppress the schematics as well as the advertisement so please disable if the schematic list is empty.

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CircuitCategoryDate AddedOK?Votes 
13.8V 30-40A Power Supply (PDF)Power Status86 vote up vote down
Yaesu FT-897 - PC interface (PDF)PC Status3 vote up vote down
AT89C2051 serial COMs to LED driverMicrocontrollerApr 12, 2001Status16 vote up vote down
RCM710 electronic scale, technical manual including schematicTestApr 12, 2001Status2 vote up vote down
RS-232 line monitor and loopback cablesPCJan 26, 2001Status3 vote up vote down
Serial to parallel converter using the AT89C2051MicrocontrollerJan 26, 2001Status-1 vote up vote down
Slave flash trigger with counting logic (Silicon Chip Mazine article)PhotoAug 18, 2009Status2 vote up vote down
Filters for the RadioJove ReceiverFilter Status0 vote up vote down
Autopilot: Do it yourself UAVModelsSep 10, 2006Status7 vote up vote down
Bridge headControlAug 14, 2002Status-6 vote up vote down
Bat detector microphone pre-amplifiersPreamp Status8 vote up vote down
Visor cradle serial interfaceGamesAug 09, 2002Status-1 vote up vote down
TomTom One V3 connector pinoutPDAMar 27, 2009Status-1 vote up vote down
Simple CW Keyer based on Atmel ATtiny 2313Microcontroller Status-1 vote up vote down
PWM motor controllerControlJun 06, 2003Status-1 vote up vote down
Single and Two Cell White LED Drivers Without InductorsLEDSep 13, 2006Status2 vote up vote down
Laser link communicator project from Electronics Australia magazineLaser Status2 vote up vote down
12V battery level indicator for car batteriesAutomotive Status9 vote up vote down
Bicycle rear flashing LED lightLED Status4 vote up vote down
Car burglar alarm circuitAutomotive Status2 vote up vote down
Decision maker circuit diagramGames Status2 vote up vote down
Egg timer circuit diagram, PCB layout and assembly informationTiming Status1 vote up vote down
Electronic candleLighting Status8 vote up vote down
Flashing light / emergency beacon for vehicleAutomotive Status-1 vote up vote down
3-up decision maker circuit diagramGames Status3 vote up vote down
Headlight guardAutomotive Status3 vote up vote down
LED dice with fast rollGames Status5 vote up vote down
Interior light extenderAutomotive Status-2 vote up vote down
Little bike light using LEDsLED Status1 vote up vote down
Simple metronome using LM1458Music Status4 vote up vote down
LED dice using PIC16F88Games Status1 vote up vote down
Simple moisture indicatorMisc Status-4 vote up vote down
LM380 2.5 watt audio amplifier circuitAmplifiers Status38 vote up vote down
One transistor FM transmitter / FM bugging deviceTransmitters Status5 vote up vote down
Two player quiz master gameGames Status-2 vote up vote down
4 channel 433MHz remote control transmitter / receiver based on SM5162 and SM5172 chipsRF Status13 vote up vote down
Seatbelt reminder circuitAutomotive Status4 vote up vote down
Solar trackerSolar Status-1 vote up vote down
Stereo audio amplifier based on TDA2822MAmplifiers Status-9 vote up vote down
Two LED trouble light systemAutomotive Status-1 vote up vote down
Two-tone doorbell using 555 timerMisc Status-4 vote up vote down
Two transistor FM transmitter / FM bugTransmitters Status1 vote up vote down
Snore alarm electronic deviceMedicalAug 14, 2002Status5 vote up vote down
Car Ignition Coil Driver from 110V ACPowerSep 23, 2009Status-10 vote up vote down
Laser beam alarm systemLaser Status-10 vote up vote down
Amplified zener regulatorPower Status-4 vote up vote down
13.5 Watt Power Amplifier using a TL081 opamp and TIP125 / TIP120 power transistorsAmplifiers Status-11 vote up vote down
Momentary High Voltage Arc Circuit - can be used to Ignite a barbeque or a Gas in a Potato GunMisc Status3 vote up vote down
Simple car battery voltage monitorAutomotive Status0 vote up vote down
Car Battery Charger, an SCR Design with a 10 Amp ratingAutomotive Status-6 vote up vote down
Car Ignition Coil Driver from 12V DC - Can be used as an electric fencePowerSep 23, 2009Status3 vote up vote down
Cat or Dog Detector - can be used to control entry on a Cat or Dog DoorMisc Status-1 vote up vote down
Battery Charger, Current and Voltage Regulated for Sealed Lead Acid batteriesPower Status-7 vote up vote down
Digital Up / Down Counter with 7-segment displayLED Status-2 vote up vote down
Delayed Power Circuit using an SCRControl Status3 vote up vote down
LED flasher with "Rising and Falling" BrightnessLEDSep 23, 2009Status0 vote up vote down
Ground Fault IndicatorTest Status-5 vote up vote down
H-Bridge CircuitControl Status0 vote up vote down
12 Volt Knight Rider LED displayLEDSep 23, 2009Status-5 vote up vote down
Digital combination lock using pair of CD4013 CMOS chipsAlarmsSep 23, 2009Status-4 vote up vote down
Low battery cut-off circuit for a car or truckAutomotiveSep 23, 2009Status2 vote up vote down
Fish caller circuitMiscSep 23, 2009Status-2 vote up vote down
Parabolic microphone project circuit (can be used with shotgun directional microphone also)AudioSep 23, 2009Status0 vote up vote down
Voltage and current regulated power supplyPowerSep 23, 2009Status-3 vote up vote down
High current PWM controller based around a 555 timerControlSep 23, 2009Status-1 vote up vote down
Electronic roulette wheel circuit diagramGamesSep 23, 2009Status-3 vote up vote down
SCA Adapter - listen to advertisement free background music on FM broadcast radioRFSep 23, 2009Status6 vote up vote down
Simple Sine Wave Oscillator including a PCB layoutTimingSep 23, 2009Status-6 vote up vote down
Solar cell battery charger circuit diagramSolarSep 23, 2009Status-6 vote up vote down
Using a speaker as a microphone - impedance matching circuitAudioSep 23, 2009Status-1 vote up vote down
Sound pressure level meterTestSep 23, 2009Status-1 vote up vote down
Powerful stun gun / taser circuit diagramMiscSep 23, 2009Status-1 vote up vote down
Simple switching power supply (mains operated)PowerSep 23, 2009Status3 vote up vote down
Relatively simple thermostat circuit diagramControlSep 23, 2009Status-1 vote up vote down
Electric heater thermostatControlSep 23, 2009Status-2 vote up vote down
TENS Circuit diagram for muscle stimulationMedicalSep 23, 2009Status5 vote up vote down
12 Volt Switching Power Supply circuit diagram and PCB layoutPowerSep 23, 2009Status-6 vote up vote down
Ultrasonic sound detector / snifferMiscSep 23, 2009Status-1 vote up vote down
Simple voltage booster based on Linear Technologies LT1372, includes PCB designPowerSep 23, 2009Status-1 vote up vote down
True RMS Watt MeterTestSep 23, 2009Status-1 vote up vote down
Two transistor FM transmitter circuit diagram and PCB layoutTransmittersSep 23, 2009Status-7 vote up vote down
Making a bistable from a normal relay, based on coil hysteresisControlJul 21, 2013Status-2 vote up vote down
Two-button control for dangerous machinesControlOct 05, 2012Status1 vote up vote down
Bicycle LED POV (persistence of vision display) LED displayLED Status-1 vote up vote down
GSM-900 Mobile Jammer Book (PDF compressed with WinRAR)TelephoneAug 01, 2010Status-2 vote up vote down
Alkaline battery chargerPowerDec 02, 2002Status0 vote up vote down
PIC16F628 controlled FLL (Frequency Locked Loop) VFO for HF (PDF)MicrocontrollerOct 05, 2009Status2 vote up vote down
Direct Digital Synthesis VFO for HF Bands - based on Analog Devices AD7009 DDS (PDF)TimingOct 05, 2009Status-1 vote up vote down
Simple Frequency Reader for conversion VFOsMiscOct 05, 2009Status2 vote up vote down
The u-counter, a PIC based programmable frequency meter (PDF)TestOct 05, 2009Status2 vote up vote down
Continuous Coverage V.F.O. for H.F. (PDF)TimingOct 05, 2009Status-2 vote up vote down
Experimental DSB/CW QRP rig for 20 and 40 meter bands (PDF)RFOct 05, 2009Status0 vote up vote down
PIC16F84 CW decoder (PDF)MicrocontrollerJul 10, 2002Status0 vote up vote down
Simple 40 meters CW QRP Transceiver (PDF)RFOct 05, 2009Status1 vote up vote down
20 meters CW QRP Transceiver (PDF)RFOct 05, 2009Status-3 vote up vote down
Heathkit modulated HeNe laser power supply kit (HK-HI1)Laser Status3 vote up vote down
Easy Xenon DC-DC Converter using LM386Lighting Status1 vote up vote down
Large collection of strobe / photoflash circuit diagramsPhotoSep 01, 2009Status-1 vote up vote down
Slave Flash Trigger CircuitPhoto Status-1 vote up vote down
Car power supply unit for digital projects, small car PCs etcAutomotive Status0 vote up vote down
Atmel AVR ATtiny45 development boardMicrocontrollerJun 28, 2011Status0 vote up vote down
RGB pattern generator based on an Atmel ATtiny2313 running at 20MHzVideoJun 28, 2011Status1 vote up vote down
Simple RS232 Level Converter based on a MAX232 including Eagle PCB and schematic filesPCJun 28, 2011Status-2 vote up vote down
AVR thermometer / thermostat based on an Atmel ATtiny2313MicrocontrollerJun 28, 2011Status-1 vote up vote down
PCB exposure countdown timer based on an Atmel ATtiny2313TimingJun 28, 2011Status1 vote up vote down
VCR ping pong gameGamesApr 27, 2004Status2 vote up vote down
Video ping pong gameGamesJul 10, 2002Status0 vote up vote down
Video Clock SuperimposerVideoJul 10, 2002Status1 vote up vote down
Video clock superimposer using PIC16C711VideoApr 27, 2004Status-2 vote up vote down
Eddie's Composting Loo fan controllerMiscMar 09, 2012Status0 vote up vote down
Dual LED dice (available in kit form)Games Status0 vote up vote down
Single LED dice kit circuit diagramGames Status-1 vote up vote down
Precision Digital AltimeterData AcquisitionMay 01, 2004Status1 vote up vote down
Highly accurate constant current source using LM4140, OP777 and MOSFETPowerMar 17, 2014Status-2 vote up vote down
MOSFET based H-Bridge controller for DC motorsControlMar 17, 2014Status4 vote up vote down
Transistor delay circuits to detect if a door is open for a long periodAlarmsJun 24, 2015Status2 vote up vote down
Interfacing a DSLR Hotshoe to an ArduinoArduinoMar 27, 2014Status6 vote up vote down
Single supply op-amp audio amplifierAmplifiersJun 24, 2015Status-6 vote up vote down
USB 0-500MHz RF Power Meter based on a AD8307RFFeb 21, 2013Status-3 vote up vote down
Serial LCD controller using a PIC16F628Microcontroller Status3 vote up vote down
Advanced LED temperature indicatorLEDOct 25, 2014Status4 vote up vote down
Simple AM transmitter using a BFW10 FETTransmittersDec 07, 2014Status3 vote up vote down
Clap operated remove control for fansControlDec 07, 2014Status0 vote up vote down
Dry cell battery chargerPowerDec 07, 2014Status4 vote up vote down
Electronics Cricket on boardGamesMar 23, 2015Status3 vote up vote down
Electronics Lucky NumberGamesOct 25, 2014Status1 vote up vote down
Simple FM receiver based on a TEA5591 ICRFMar 23, 2015Status-6 vote up vote down
Long Time Period Automatic TimerTimingOct 25, 2014Status-2 vote up vote down
Microprocessor based home security systemMicrocontrollerOct 25, 2014Status1 vote up vote down
PC-based candle ignitor (parallel port based design)PCDec 07, 2014Status0 vote up vote down
PC-Based DC Motor Speed ControllerPCOct 25, 2014Status-3 vote up vote down
Power Supply Resumption Alarm using 555 timerPowerOct 25, 2014Status-4 vote up vote down
Presure based hit switchControlDec 07, 2014Status-1 vote up vote down
Sensitive Optical Burglar AlarmAlarmsOct 25, 2014Status-3 vote up vote down
Simple FM transmitter using a single transistorTransmittersMar 23, 2015Status1 vote up vote down
Simple quiz display using 74 series logic chipsGamesMar 23, 2015Status2 vote up vote down
Single chip dice using a 4060 chipGamesDec 07, 2014Status1 vote up vote down
Solid-state voltage indicator with high voltage cutoutPowerDec 07, 2014Status0 vote up vote down
Sound operated music bell using 555 timerAlarmsDec 07, 2014Status-1 vote up vote down
Stabilized Power Supply With Short-Circuit IndicationPowerOct 25, 2014Status-1 vote up vote down
Stereo audio simulatorAudioMar 23, 2015Status0 vote up vote down
Temperature Indicator Using AT89C52MicrocontrollerDec 07, 2014Status-1 vote up vote down
Touch operated Band switch for Radio SetMiscOct 25, 2014Status0 vote up vote down
Trangular wave generatorTimingMar 23, 2015Status0 vote up vote down
Capacitor voltage stepper using 555 timerPowerDec 07, 2014Status-2 vote up vote down
White / LF noise generatorAudioDec 07, 2014Status-1 vote up vote down
Wind Sound GeneratorAudioOct 25, 2014Status-1 vote up vote down
Home Built Laser ProjectorLaser Status-1 vote up vote down
Arduino Mega 2560 schematic (PDF) - Arduino R3ArduinoJul 21, 2013Status-1 vote up vote down
DPA 220 amplifier schematicAmplifiers Status-5 vote up vote down
Low impedance microphone amplifierAmplifiers Status-4 vote up vote down
DPA 440 amplifier schematicAmplifiers Status0 vote up vote down
Low pass filter for subwooferFilter Status3 vote up vote down
Portable Mixer with high-quality modular design (9V battery powered)Music Status-1 vote up vote down
100W audio amplifier including PCB layoutAmplifiersApr 14, 2011Status-22 vote up vote down
Quadraphonic Amplifier based on pair of LM1877 devicesAmplifiers Status-3 vote up vote down
DPA 880 amplifier schematicAmplifiers Status-4 vote up vote down
Class-A/AB Amplifier delivering 100W into a 4 ohm loadAmplifiers Status-7 vote up vote down
Audio Indicator - monitor a loudspeaker, alarm, or audio source for presence of an audio waveformAudio Status-1 vote up vote down
Stereo Audio IsolatorAudio Status0 vote up vote down
Guitar Reverb Effect Version 2Music Status-1 vote up vote down
Guitar Reverb PedalMusic Status0 vote up vote down
Voltage Controlled PannerAudio Status2 vote up vote down
25 Watt MOSFET Audio Amplifier using IRF532 / IRF9532 hexfet transistors for output stageAmplifiers Status-3 vote up vote down
Large capacitor charge "controllers" (Car Audio)Automotive Status2 vote up vote down
Easy to build DIY 50W amplifier based on ICL8063Amplifiers Status3 vote up vote down
Audio VU Meter based on pair of LM324 quad opampsAmplifiers Status1 vote up vote down
Voice-Over CircuitAudio Status-2 vote up vote down
20 Watt Audio Power Amplifier using TDA2005MAmplifiers Status-4 vote up vote down
22 Watt Stereo Amplifier using TDA1554Amplifiers Status-4 vote up vote down
Two Transistors Audio AmplifierAmplifiers Status-2 vote up vote down
10 Watt Audio Amplifier circuit diagramAmplifiers Status-4 vote up vote down
Underwater microphone used in a home aquarium to monitor fish soundsAudio Status-2 vote up vote down
DIY intervalometer for Sony NEX 5N cameraPhotoJun 14, 2015Status2 vote up vote down
DIY DC Amp Volt Watt Meter using an Arduino and ZXCT1010ArduinoJun 14, 2015Status0 vote up vote down
DIY Infrared Thermometer using Arduino Nano and MLX90614ArduinoJun 14, 2015Status-1 vote up vote down
Speed limit alertAutomotiveJul 05, 2012Status-3 vote up vote down
Motorcycle AlarmAlarmsJul 05, 2012Status2 vote up vote down
Car Alarm and ImmobilizerAlarmsJul 05, 2012Status-1 vote up vote down
Car Hijack AlarmAlarmsJul 05, 2012Status-1 vote up vote down
Motorcycle Alarm Number 2AlarmsJul 05, 2012Status1 vote up vote down
Motorcycle Alarm Number 3AlarmsJul 05, 2012Status-4 vote up vote down
Motorcycle Alarm Number 4AlarmsJul 05, 2012Status-3 vote up vote down
Motorcycle Alarm Number 5 & 6AlarmsJul 05, 2012Status1 vote up vote down
Park-Aid - Three LEDs signal bumper-barrier distanceAutomotiveJul 05, 2012Status-2 vote up vote down
Headlight FlasherAutomotiveJul 05, 2012Status3 vote up vote down
Car Voltage Gauge with 7-segment readoutAutomotiveJul 05, 2012Status-1 vote up vote down
Car Water Temperature Gauge with 7-segment readoutAutomotiveJul 05, 2012Status1 vote up vote down
Auto Burglar AlarmAlarmsJul 05, 2012Status0 vote up vote down
Automotive Speed IndicatorAutomotiveJul 05, 2012Status0 vote up vote down
Simple but reliable car battery tester using LM3914AutomotiveJul 05, 2012Status1 vote up vote down
Automotive 12V to +-20V converter (for audio amplifier)AutomotiveJul 05, 2012Status-1 vote up vote down
Electronic car ignitionAutomotiveJul 05, 2012Status0 vote up vote down
Car battery charger with automatic cutoffAutomotiveJul 05, 2012Status-4 vote up vote down
Automatic Headlight Brightness SwitchAutomotiveJul 05, 2012Status3 vote up vote down
Dome Lamp DimmerAutomotiveJul 05, 2012Status0 vote up vote down
Light switch using LDRControlJun 26, 2009Status-3 vote up vote down
Digital Remote ThermometerMiscJun 26, 2009Status0 vote up vote down
Fridge door AlarmAlarmsJun 26, 2009Status-1 vote up vote down
Room Noise DetectorAudioJun 26, 2009Status-1 vote up vote down
Capacitive SensorMiscJun 26, 2009Status1 vote up vote down
Ultra-simple Voltage ProbeTestJun 26, 2009Status1 vote up vote down
Emergency Light & AlarmAlarmsJun 26, 2009Status1 vote up vote down
Heating System ThermostatControlJun 26, 2009Status-2 vote up vote down
Touch switch based on CD4011 flip-flopControlJun 26, 2009Status-2 vote up vote down
Door Alarm circuit diagramAlarmsJun 26, 2009Status0 vote up vote down
Mains Remote-Alert - Remotely operates beeper and/or a LED via mains supply lineMiscJun 26, 2009Status-2 vote up vote down
Low Voltage Alarm for batteries and other volatile DC power sourcesPowerJun 26, 2009Status-3 vote up vote down
Touch activated switch using CD4011 CMOS NAND gateMiscJun 26, 2009Status1 vote up vote down
Voice activated switch (VOX) circuit diagramMiscJun 26, 2009Status0 vote up vote down
Everything-that-moves alarm works by inducing eddy currents in living beingsAlarmsJun 26, 2009Status-1 vote up vote down
Electronic locker digital combination lock circuit diagramAlarmsJun 26, 2009Status-2 vote up vote down
Electronic Eavesdropping Devices DetectorRFJun 26, 2009Status1 vote up vote down
Simple Infa-Red Remote ControlIRJun 26, 2009Status2 vote up vote down
IR Remote Control Extender CircuitIRJun 26, 2009Status2 vote up vote down
Gate alarmAlarmsJun 26, 2009Status-3 vote up vote down
Circuit diagram for 5 Zone Alarm SystemAlarmsJun 26, 2009Status-3 vote up vote down
Miniature Loop AlarmAlarmsJun 26, 2009Status3 vote up vote down
Modular Burglar AlarmAlarmsJun 26, 2009Status-1 vote up vote down
Water Activated AlarmAlarmsJun 26, 2009Status-2 vote up vote down
Novel buzzer using a relay and transformerAudioJun 26, 2009Status-3 vote up vote down
Radio Wave AlarmRFJun 26, 2009Status1 vote up vote down
Enhanced 5 Digit Alarm KeypadAlarmsJun 26, 2009Status-1 vote up vote down
Enhanced 4 Digit Alarm KeypadAlarmsJun 26, 2009Status-1 vote up vote down
Automatic Intruder AlarmAlarmsJun 26, 2009Status0 vote up vote down
Single Zone CMOS AlarmAlarmsJun 26, 2009Status-2 vote up vote down
Travel Touch AlarmAlarmsJun 26, 2009Status0 vote up vote down
UltraSonic RadarMiscJun 26, 2009Status0 vote up vote down
Cuckoo sound GeneratorAudio Status1 vote up vote down
TRIAC Light DimmerLighting Status2 vote up vote down
LEDs or Lamps Sequencer is versatile modular design with no limits on number of lightsLighting Status-2 vote up vote down
Battery-powered Night LampLighting Status0 vote up vote down
Courtesy light circuit diagramLighting Status1 vote up vote down
Brightness Control for small LampsLighting Status-2 vote up vote down
12VDC Fluorescent Lamp DriverLighting Status-1 vote up vote down
LED Chaser using 4011 / 4017 CMOS chipsLED Status-2 vote up vote down
Adjustable Strobe LightLighting Status0 vote up vote down
Fading LEDsLED Status0 vote up vote down
Dancing LEDs circuit diagramLED Status-1 vote up vote down
Black Light powered by a 6 volt batteryLighting Status1 vote up vote down
DC Motor Control CircuitControl Status2 vote up vote down
Fan control based on a TL082 opamp and IRF510 power MOSFETControl Status-2 vote up vote down
Bicycle back Safety LightLighting Status0 vote up vote down
Simple LASER Transmitter/Receiver using HeNe laser tubeLaser Status4 vote up vote down
LASER Transmitter/Receiver using Pulse Width Modulator (PWM) for 12V / 24V applicationsLaser Status1 vote up vote down
Nocturnal Animals WhiskerMisc Status1 vote up vote down
Seven Component Regulated LED LampLED Status3 vote up vote down
LED Mood LightLED Status-3 vote up vote down
13 Color LED Rainbow circuit diagramLED Status5 vote up vote down
Lightning Activated Camera Shutter TriggerPhoto Status-1 vote up vote down
Electronic CanaryAudio Status0 vote up vote down
Metronome CircuitMusic Status1 vote up vote down
Sun - Up Alarm that provides an audible alarm when the sun comes up or a dark area is illuminatedAlarms Status-2 vote up vote down
Assortment of Siren CircuitsAudioSep 17, 2009Status-1 vote up vote down
60 LED ClockLED Status-2 vote up vote down
Bike Light FlasherLighting Status0 vote up vote down
Simple 120 VAC motor speed controller based on a TRIACControl Status-4 vote up vote down
PIC Light Chaser using PIC16C84Microcontroller Status-2 vote up vote down
Wire tracerTest Status-3 vote up vote down
Flashing neon christmas lightsLighting Status-1 vote up vote down
Doorbell for the DeafAlarms Status-4 vote up vote down
Insect RepellantMiscSep 17, 2009Status-2 vote up vote down
220 Volts Flashing LampsLighting Status-5 vote up vote down
IR Audio linkIRJul 05, 2012Status-3 vote up vote down
Wireless IR headphone transmitterIRJun 28, 2009Status0 vote up vote down
Wireless IR headphone receiverIRJun 28, 2009Status0 vote up vote down
IR illuminator for night-vision tv cameras and scopesIRJun 28, 2009Status0 vote up vote down
Infra Red Switch that works with commonly available remote controlsIRJul 05, 2012Status0 vote up vote down
Infra Red Remote Control Extender (Mark 1)IRJul 05, 2012Status0 vote up vote down
IR Remote Control TesterTestJul 05, 2012Status-1 vote up vote down
IR Remote Control Extender Circuit (Mark 2)IRJul 05, 2012Status0 vote up vote down
IR Remote Control Extender Circuit (Mark 3)IRJul 05, 2012Status0 vote up vote down
IR Remote Control Extender Circuit (Mark 4)IRJul 05, 2012Status0 vote up vote down
IR Remote Control Extender Circuit (Mark 5)IRJul 05, 2012Status1 vote up vote down
Infrared Remote Control that operates on 115 volts ACIRJul 05, 2012Status1 vote up vote down
Three channel audio spectrum analyzerAudioOct 21, 2009Status0 vote up vote down
Digital Voltmeter using ICL7107TestSep 17, 2009Status-3 vote up vote down
Triangle / Squarewave Generator using a 1458 dual opampTimingOct 21, 2009Status1 vote up vote down
Beeper to find short circuitsTestOct 19, 2009Status-2 vote up vote down
Voltage follower with 1G ohm input resistance based on LM11 opampPreampOct 21, 2009Status0 vote up vote down
Led display digital Voltmeter using ICL7107TestSep 17, 2009Status0 vote up vote down
MOSFET transistor testerTestNov 05, 2009Status-6 vote up vote down
Precision Audio MillivoltmeterAudioSep 17, 2009Status0 vote up vote down
Oscilloscope testing module (huntron circuit)TestNov 10, 2009Status2 vote up vote down
Voltage Monitor using UA741 operational amplifierPowerOct 19, 2009Status-3 vote up vote down
Logic probeTestOct 19, 2009Status0 vote up vote down
Digital Radar SpeedometerMiscOct 21, 2009Status-2 vote up vote down
Digital Volume Control based around CD4067 CMOS chipsAudioOct 19, 2009Status-2 vote up vote down
Electromagnetic Field Probe with Meter Output using an LF351 opampMiscOct 19, 2009Status-2 vote up vote down
Three-Level Audio Power IndicatorAudioOct 19, 2009Status-1 vote up vote down
Beat Balance Metal DetectorMetal Status65 vote up vote down
Coil Coupled Operation Metal DetectorMetalNov 10, 2009Status-4 vote up vote down
Expanded Scale Battery Volt MeterPowerSep 17, 2009Status0 vote up vote down
Pulse Reading Logic ProbeTestOct 19, 2009Status0 vote up vote down
Stereo Test Tone GeneratorTestOct 21, 2009Status-2 vote up vote down
Continuity Tester based on 4 x 2N3904 and 1 x 2N3905 transistorsTestOct 19, 2009Status0 vote up vote down
Audible Logic Probe based on LM339 operational amplifierTestOct 19, 2009Status0 vote up vote down
Single chip digital voltmeter using ICL7129TestNov 05, 2009Status-1 vote up vote down
Latching Continuity Tester to help find intermittent faults, has quite a few innovative featuresTestOct 19, 2009Status1 vote up vote down
Infrared remote control tester using a SFH2030 photodiode and a CA3140 operational amplifierIROct 19, 2009Status1 vote up vote down
Linear Resistance MeterTestOct 19, 2009Status-4 vote up vote down
XTal Tester for testing quartz crystals based on a pair of BC550C PNP transistorsTestOct 19, 2009Status-1 vote up vote down
Simple RC car for beginners (Android control via Bluetooth)ModelsJun 14, 2015Status0 vote up vote down
Arduino RC car (Android control via Bluetooth)ArduinoJun 14, 2015Status-2 vote up vote down
STM32 RC car (Android control via Bluetooth)ModelsJun 14, 2015Status2 vote up vote down
Lighting control with Android device through BluetoothLightingJun 14, 2015Status0 vote up vote down
Android controlled RC Vehicle with real-time video (Bluetooth & Wi-Fi)ModelsJun 14, 2015Status-2 vote up vote down
Portable GSM900 Cellular Phone JammerTelephoneAug 01, 2010Status1 vote up vote down
High Power 800 MHz/AMPS Cellular Phone JammerTelephoneAug 01, 2010Status0 vote up vote down
Cellular Phone Jammer. Ver 2 circuit diagramTelephoneAug 01, 2010Status0 vote up vote down
Portable AMPS Cellular Phone JammerTelephoneAug 01, 2010Status2 vote up vote down
Portable AMPS Cellular Phone Jammer - Dual PurposeTelephoneAug 01, 2010Status-1 vote up vote down
PCS Phone Jammer circuit diagramTelephoneAug 01, 2010Status0 vote up vote down
Portable PCS Cellular Phone Jammer circuit schematicTelephoneAug 01, 2010Status0 vote up vote down
PCS Cellular Phone Jammer circuit schematicTelephoneAug 01, 2010Status2 vote up vote down
GBPPR Cellular Phone Jammer Exciter schematic diagramTelephoneAug 01, 2010Status1 vote up vote down
Cellular Phone Jammer RF Amplifier circuit diagramTelephoneAug 01, 2010Status0 vote up vote down
Homebrew P2JBZ-style cellular / mobile phone jammer circuitTelephoneAug 01, 2010Status0 vote up vote down
Self-powered Fast Battery-Tester - Tests 1.5 to 15 Volt cellsTestSep 17, 2009Status0 vote up vote down
Battery Low Voltage BeeperPowerSep 17, 2009Status-1 vote up vote down
AA Battery Solar ChargerSolarSep 17, 2009Status1 vote up vote down
4 Transistor Tracking TransmitterTransmitters Status0 vote up vote down
AM TransmitterTransmitters Status-5 vote up vote down
FM Telephone BugTelephone Status0 vote up vote down
FM Transmitter using two transistorsTransmitters Status1 vote up vote down
AM/FM Simultaneous Transmitter Using Digital ICTransmitters Status4 vote up vote down
Medium range transmitter using pair of 2N3904 transistorsTransmitters Status2 vote up vote down
15 watt FM transmitter circuit diagramTransmitters Status1 vote up vote down
AM TransmitterTransmitters Status-1 vote up vote down
Single transistor FM transmitterTransmitters Status2 vote up vote down
Small FM transmitter using SMD componentsTransmitters Status0 vote up vote down
Miniature FM TransmitterTransmitters Status0 vote up vote down
Low Power FM TransmitterTransmitters Status0 vote up vote down
FM Voice TransmitterTransmitters Status0 vote up vote down
Sensitive FM TransmitterTransmitters Status2 vote up vote down
Small FM TransmitterTransmitters Status-1 vote up vote down
TV Signal Amplifier covers frequencies from 40MHz to 900 MHzVideoJun 28, 2009Status1 vote up vote down
Linear FM 50Watt with BLY90RFJun 28, 2009Status-4 vote up vote down
Motorized Video Camera MountVideoJun 28, 2009Status-1 vote up vote down
TV Transmitter - VHF band TV transmitter using negative sound modulation and PAL video modulationVideoJun 28, 2009Status-2 vote up vote down
UHF Preamplifier covers 450MHz - 800MHz based on MPSH10 / BF180 / BCY90RF_AmplifierJun 28, 2009Status-1 vote up vote down
60W Linear amplifier using IRF840 power MOSFETRF_AmplifierJun 28, 2009Status-2 vote up vote down
Video Signal AmplifierVideoJun 28, 2009Status1 vote up vote down
Cellular Phone calling DetectorTelephoneSep 17, 2009Status-1 vote up vote down
Simple Phone Tap circuit diagramTelephoneAug 12, 2009Status-2 vote up vote down
Telephone Hold Button circuitTelephoneAug 12, 2009Status-1 vote up vote down
Telephone recorder to record phone conversations automaticallyTelephoneAug 12, 2009Status-1 vote up vote down
Cellular Phone calling DetectorTelephoneAug 12, 2009Status0 vote up vote down
Phone line indicatorTelephoneSep 17, 2009Status0 vote up vote down
Isolated Telephone InterfaceTelephoneAug 12, 2009Status0 vote up vote down
Telephone Record Control using 2N4360, 2N2222 and 2N2102TelephoneAug 12, 2009Status0 vote up vote down
Voice ScramblerAudioAug 12, 2009Status-1 vote up vote down
Phone In Use Indicator circuit diagramTelephoneSep 17, 2009Status1 vote up vote down
Phone "Hold" With MusicTelephoneAug 12, 2009Status-1 vote up vote down
Voice / Audio Record / Playback CircuitAudioAug 12, 2009Status-2 vote up vote down
Simple speakerphoneTelephoneAug 12, 2009Status0 vote up vote down
High Quality Intercom using LM380 amplifier ICTelephoneAug 12, 2009Status0 vote up vote down
Soft Musical Telephone RingerTelephoneAug 12, 2009Status0 vote up vote down
Telephone amplifierTelephoneAug 12, 2009Status-3 vote up vote down
Cut Phone Line DetectorTelephoneAug 12, 2009Status0 vote up vote down
Telephone line monitorTelephoneAug 12, 2009Status0 vote up vote down
Phone Busy IndicatorTelephoneAug 12, 2009Status-1 vote up vote down
Ringing Phone Light Flasher using optocoupler and relayTelephoneAug 12, 2009Status0 vote up vote down
ADC conversion using ADC0804LCN and 8051Microcontroller Status-1 vote up vote down
Build a Tape Linearizer and a Distortion AnalyzerAudioApr 14, 2010Status-1 vote up vote down
Peak-reading metersAudioJan 26, 2001Status-1 vote up vote down
Microphone polarity tester circuit diagranTestApr 14, 2010Status-2 vote up vote down
Audio Spectrum Analyzer and Equalizer DesignsAudioMar 30, 2010Status-2 vote up vote down
Build A Stereo SynthesizerMusicMay 07, 2010Status1 vote up vote down
Electronic Control for DC Motors Using Discrete Bridge Circuits (PDF)Control Status0 vote up vote down
Defeating SCMS on DAY recorders using a Sony CXD2601 chipAudioMay 07, 2010Status-1 vote up vote down
Bell 202 and CCITT V23 Compatible FSK Modem CircuitPCOct 27, 2009Status-1 vote up vote down
Strobo Disco Light Using Standard Tube Lamp (TL)Lighting Status5 vote up vote down
Heartbeat Sensor (Tranduscer)MedicalJan 08, 2014Status1 vote up vote down
Low Cost Universal Battery ChargerPowerJan 08, 2014Status-2 vote up vote down
26V-to-5000V DC-DC ConverterPowerJan 08, 2014Status-2 vote up vote down
Ring-Around LED FlasherLEDJan 08, 2014Status0 vote up vote down
Black Light (UV Tube Lamp) InverterLightingJan 08, 2014Status1 vote up vote down
15 Channels Cascaded MAX455 Video MuxVideoJan 08, 2014Status1 vote up vote down
Digital Encoder Circuit Using Stepper MotorControlJan 08, 2014Status3 vote up vote down
30-Khz Bandwidth High Linearity Opto-Isolated AmplifierAmplifiersJan 08, 2014Status-1 vote up vote down
Three Wire RS232 To RS485 ConverterPCJan 08, 2014Status-2 vote up vote down
Low-Drift High-Impedance JFET DC VoltmeterTestJan 08, 2014Status-2 vote up vote down
Telephone Circuit: Music On HoldTelephoneOct 03, 2013Status0 vote up vote down
Loud 10-W Car Alarm SirenAutomotiveOct 03, 2013Status1 vote up vote down
Missing Pulse Detector Circuit with 555 ICMiscOct 03, 2013Status-1 vote up vote down
Binaural Synthesizer/Mono to Stereo Converter for Small Speaker/PhonesAudioOct 03, 2013Status-2 vote up vote down
Fast Charger for Better Lead-Acid Battery LifePowerOct 03, 2013Status0 vote up vote down
5 A Constant Voltage-Constant Current RegulatorPowerOct 03, 2013Status-1 vote up vote down
Voltage Controlled Variable Gain Video AmplifierVideoOct 03, 2013Status0 vote up vote down
Tremolo Effect Circuit for Electric Guitar or Other Musical InstrumentsMusicOct 03, 2013Status2 vote up vote down
PC Audio Signal Generator Using RS232 PortPCOct 03, 2013Status-2 vote up vote down
Powerline Carrier System Transmitter for Audio (Music/Speech)AudioOct 03, 2013Status0 vote up vote down
Compact 3W BTL Audio Power Amplifier TDA7056AmplifiersOct 03, 2013Status-5 vote up vote down
CamTrig - A home-made light-operated camera triggerPhoto Status0 vote up vote down
A simple home-made light-operated camera triggerPhoto Status0 vote up vote down
A home-made light-operated camera trigger using the stamp microprocessorPhoto Status0 vote up vote down
Resistor decade boxTestAug 14, 2002Status-2 vote up vote down
Gameboy MIDI interface circuit schematic and notes on Linux development for GameboyPDAFeb 05, 2010Status0 vote up vote down
Octave screamerMusicJan 26, 2001Status-3 vote up vote down
Atari Punk Console schematicsGamesOct 04, 2010Status1 vote up vote down
Build A Roomba Bluetooth AdapterModels Status-2 vote up vote down
Chaos generatorMiscJan 26, 2001Status-2 vote up vote down
Various CNC mill circuit diagrams and other DIY CNC mill informationControlJun 17, 2011Status-1 vote up vote down
5W Chinese PLL FM Transmitter With LCD Printed Circuit Board (PCB)Transmitters Status1 vote up vote down
Simple test equipment to buildTest Status-2 vote up vote down
A Two-Way Morse Practice SetMisc Status0 vote up vote down
Send Morse on your VHF RigRF Status-1 vote up vote down
An end-fed antenna, L-match coupler and resistive bridge for HFRF Status-3 vote up vote down
Regenerative receiver for the AM broadcast band using two transistorsRF Status0 vote up vote down
Two Valve 40m CW TransmitterTube Status1 vote up vote down
Novel crystal set requires no antenna, earthRF Status1 vote up vote down
80 meter direct conversion receiverRF Status0 vote up vote down
3 - 12 MHz Signal GeneratorTiming Status1 vote up vote down
A compact L-match ATU for portable useRF Status0 vote up vote down
80m ceramic resonator VXO CW transmitterTransmitters Status0 vote up vote down
RF Power Meter for the QRP measures up to 25 wattsTest Status3 vote up vote down
Converter to yune six metres on your two metre receiverRF Status0 vote up vote down
80 Metre DSB TransmitterTransmitters Status0 vote up vote down
High quality AM through your FM stereoRF Status-2 vote up vote down
Signal Frequency Beat Frequency OscillatorTiming Status0 vote up vote down
Dip Oscillator for HFTest Status1 vote up vote down
Converter to Hear Amateurs on your FM RadioRF Status0 vote up vote down
RF Actuated Keying MonitorRF Status0 vote up vote down
LF to HF ConverterRF Status-3 vote up vote down
CMOS IC 1 kHz Audio OscillatorAudio Status0 vote up vote down
One Valve CW transmitterTube Status0 vote up vote down
1A Variable Regulated Power SupplyPower Status-1 vote up vote down
Super 80 ultra-simple SSB receiver for 3.5 MHz a basic superhetRF Status-1 vote up vote down
Two Tone Audio OscillatorAudio Status-2 vote up vote down
Wide-swing Variable Crystal OscillatorTiming Status0 vote up vote down
Palm PDA based dataloggerPDA Status0 vote up vote down
Traffic light controller with 20-output sequencingModelsSep 10, 2006Status0 vote up vote down
4 Photo-Detector circuit with delayed release and bipolar outputAlarmsAug 18, 2009Status-1 vote up vote down
5 Times Around CircuitModelsSep 10, 2006Status2 vote up vote down
8 Photo-Detector Circuit BoardData AcquisitionSep 10, 2006Status0 vote up vote down
Fast Electronic Circuit Breaker for Model RailwaysModelsNov 13, 2010Status0 vote up vote down
Automatic - Railway Grade Crossing Circuit (2008 design)Models Status0 vote up vote down
Audible Train Approach Warning CircuitModelsSep 10, 2006Status1 vote up vote down
Across The Track Infrared DetectorsModelsSep 10, 2006Status0 vote up vote down
Automatic Reversing Circuit for Model TrainsModelsNov 13, 2010Status-1 vote up vote down
Voltage Comparator Information And CircuitsMiscApr 27, 2003Status-1 vote up vote down
Block Occupancy Detector For DCCModels Status1 vote up vote down
Rail Crossing Diamond Protection CircuitModelsSep 10, 2006Status1 vote up vote down
Automatic Railway Grade Crossing FlashersModelsSep 10, 2006Status1 vote up vote down
H Bridge Motor Control CircuitsControlJun 09, 2002Status-3 vote up vote down
Incline Railway Control CircuitModelsJan 01, 2003Status-1 vote up vote down
Infrared Proximity Detector based on Vishay TSOP4830IR Status-1 vote up vote down
LM3909 replacement using discrete componentsLEDFeb 14, 2003Status-1 vote up vote down
Model Railroad Odometer CarModelsSep 10, 2006Status0 vote up vote down
Visible and Infrared Light DetectorsMisc Status0 vote up vote down
Turnout Anti-Derail Protection CircuitsModelsSep 10, 2006Status-1 vote up vote down
Regulated Power Supply CircuitsPowerSep 10, 2006Status0 vote up vote down
Single Traffic Light Driver CircuitModelsNov 13, 2010Status0 vote up vote down
Basic Solid State RelaysPowerSep 10, 2006Status-3 vote up vote down
Unipolar and bipolar stepper motor driver circuits using 74194 and ULN2803ControlNov 04, 2011Status-1 vote up vote down
Various Transistor Throttles Cicuit SchematicsModelsSep 10, 2006Status-1 vote up vote down
Three Terminal Regulator Type Throttle (LM350K)ModelsSep 10, 2006Status0 vote up vote down
1200 Watt Lamp Dimmer Circuit using Q4015LT combination DiacLightingSep 10, 2006Status-2 vote up vote down
LM311 Thermostat circuit diagramsPower Status-1 vote up vote down
10, 8 And 6 Step LED Circuits (CD4017)LEDSep 10, 2006Status0 vote up vote down
5 Second Ramp Generator for Locomotive Sound Card DemonstrationModels Status1 vote up vote down
Transformer Secondary Voltage ReductionPower Status1 vote up vote down
Adding External Meters to DC ThrottlesModels Status1 vote up vote down
Back And Forth - Bidirectional Bipolar Stepper Motor DriverPower Status1 vote up vote down
Grade Crossing Bell Ringer (LM555)Models Status0 vote up vote down
CA4060B Timer CircuitsTimingSep 10, 2006Status-2 vote up vote down
Train Mounted Camera Battery ChargerModels Status2 vote up vote down
Using Common Cathode Or Anode LEDs As Bipolar LEDsLED Status0 vote up vote down
Timed Uncoupling Ramp Driver (LM555)ModelsSep 10, 2006Status0 vote up vote down
Colour Shifting For Bi-Colour LED'sLEDSep 10, 2006Status-3 vote up vote down
Light Activated Detector Circuit (LM393/LM555)MiscSep 10, 2006Status0 vote up vote down
Diode Type Constant Lighting CircuitsLightingSep 10, 2006Status0 vote up vote down
High Side Current Monitors (LM358, Zetex - ZXCT-1009)PowerSep 10, 2006Status0 vote up vote down
Current Regulators For Light Emitting DiodesLEDSep 10, 2006Status-1 vote up vote down
DCC To DC - Accessory Power SuppliesModels Status0 vote up vote down
Grouped DCC Block Occupancy DetectorsModelsSep 10, 2006Status1 vote up vote down
HIGH or LOW Power Switch For Lights or Small MotorsControlSep 10, 2006Status-1 vote up vote down
High Impedance VoltmeterTestSep 10, 2006Status-1 vote up vote down
Incandescent LED CircuitLEDSep 10, 2006Status0 vote up vote down
Model Railroad - Infrared Proximity SwitchModels Status2 vote up vote down
Infrared Receiver Module SchematicsIRSep 10, 2006Status1 vote up vote down
Various LM555 LED Blinker CircuitsLEDSep 10, 2006Status1 vote up vote down
Low Battery Voltage Cutout CircuitsPowerSep 10, 2006Status-2 vote up vote down
Preselect Twin Coil Switch Machine CircuitPower Status-3 vote up vote down
First Across The Line Race Scorer CircuitsModelsSep 10, 2006Status-1 vote up vote down
School Bus Signals CircuitModelsSep 10, 2006Status-1 vote up vote down
N.O. Magnetic Reed Switch ON /OFF Circuit (SCR equivalent)Power Status-2 vote up vote down
Servo Motor Test Circuit (LM555)Test Status0 vote up vote down
Special Function Timer Circuits (LM555)TimingSep 10, 2006Status2 vote up vote down
Team digital - SCR16 - Twin Coil Switch Machine AdapterPower Status-1 vote up vote down
LED Out Circuit For Tortoise Switch MachinesModels Status0 vote up vote down
Push Button Motor Control CircuitsControlSep 10, 2006Status0 vote up vote down
Timed DC ThrottleModelsSep 10, 2006Status0 vote up vote down
Efficient unipolar stepper motor driver (only uses power when it makes a step)Power Status0 vote up vote down
DCC - Zero Stretching Simulator (LM555)ModelsSep 10, 2006Status0 vote up vote down
10 GHz CW Radar based on a X-band GunnplexerMisc Status-1 vote up vote down
Self made data-logger V2.5 (second edition)Data AcquisitionNov 27, 2002Status-3 vote up vote down
GoldPic 3 Pulse Induction Metal Detector (has electronic kit available)MetalMay 30, 2007Status-8 vote up vote down
Photodiode primer and interface circuit diagrams including photovoltaic and photoconductive modesMiscMar 04, 2010Status0 vote up vote down
Build a PIC controlled DDS VFO, 0 to 6 MHzMicrocontrollerJul 12, 2001Status-5 vote up vote down
MBC5/CPLD for the GameBoyGamesOct 31, 2002Status1 vote up vote down
10W 2M CW transmitter circuit diagramTransmittersJun 19, 2011Status-1 vote up vote down
50 MHz to 10 MHz receive converterRFJun 19, 2011Status1 vote up vote down
17M to 6M transveter circuit diagramRFJun 19, 2011Status-1 vote up vote down
metre receiverRFJun 19, 2011Status-2 vote up vote down
Passive grid (tube based) linear amplifierTubeJun 19, 2011Status0 vote up vote down
T-Match ATU (antenna tuning unit)RFJun 19, 2011Status-2 vote up vote down
Fourth order Butterworth BPF circuit diagram and design notesFilterJun 19, 2011Status-2 vote up vote down
Frequency counter based on PIC16F628 and LCD displayTestJun 19, 2011Status-4 vote up vote down
10MHz GPS disciplined frequency standardTimingJun 19, 2011Status-1 vote up vote down
Iambic keyer based on a PIC16F84 or PIC16C84MicrocontrollerJun 19, 2011Status0 vote up vote down
Chebyshev low pass filter, rolls of at 30MHzFilterJun 19, 2011Status0 vote up vote down
PIC18F4550 Development Board including PCB layout suitable for home etchingMicrocontrollerJun 19, 2011Status-1 vote up vote down
Single transistor receiver for SSB, CW, AM using a VHF dual gate MOSFETRFJun 19, 2011Status0 vote up vote down
Multi band SSB transceiver construction projectRFJun 19, 2011Status-1 vote up vote down
Receiver building blocksRFSep 06, 2001Status2 vote up vote down
Digital display and VFO stabiliser using a PIC microcontroller and LCDRFJun 19, 2011Status1 vote up vote down
SSB transceiver for 80MRFJun 19, 2011Status-1 vote up vote down
Simple CW transmitter for 80MTransmittersJun 13, 2011Status-1 vote up vote down
VHF receiver convertererRF Status-1 vote up vote down
A Receive Signal DecoderModelsOct 30, 2002Status1 vote up vote down
Motor speed controllersControlJun 17, 2003Status-1 vote up vote down
How to install LED lights to Mini-Z model car (based on PIC12C509)GamesNov 05, 2009Status-1 vote up vote down
Alternative power source for Magellan GPS receiversPowerMay 01, 2004Status0 vote up vote down
PIC16F84 line following robotMicrocontrollerJan 26, 2001Status-2 vote up vote down
8 x 8 Audio-video switchVideoMar 23, 2003Status0 vote up vote down
Commodore 64 24-bit parallel port interface with 8255PCMar 23, 2003Status0 vote up vote down
PIC16C505 IR / wireless remote controlMicrocontrollerMar 23, 2003Status-2 vote up vote down
DIY 2^16 encoder based on PICMicrocontrollerApr 12, 2014Status-2 vote up vote down
Electronic door codelock (PIC16F84)AlarmsMar 23, 2003Status-1 vote up vote down
Automatic door opener with PIC12C508MicrocontrollerMar 01, 2001Status-2 vote up vote down
Full-duplex doorphone with 3 wires connectionMiscMar 23, 2003Status0 vote up vote down
Infrared gate for doorIRMar 23, 2003Status1 vote up vote down
Infrared circuits for remote controlIRMar 23, 2003Status0 vote up vote down
Serial port controller infrared transmitter (PIC16F628)IRMar 23, 2003Status0 vote up vote down
Dual light timer based on PIC - Automatically turn off the lights after 10 minutesLightingApr 12, 2014Status-3 vote up vote down
3-wire serial LCD interface for the PICMicrocontroller Status-1 vote up vote down
Learning IR remote control receiver using a PIC16F628IRApr 12, 2014Status-1 vote up vote down
Low impedance microphone amplifierPreampMar 23, 2003Status-6 vote up vote down
RS485-like multi-drop bus with half duplex serial protocolMicrocontrollerMar 23, 2003Status-1 vote up vote down
EPCOS Principles of SAWR-stabilized oscillators and transmitters application notes (PDF)TransmittersApr 12, 2014Status-2 vote up vote down
Circuit diagrams for 418/433 MHz short-range communication (Elektor Electronics article)RFApr 12, 2014Status3 vote up vote down
88 - 108MHz FM audio transmitter / bug circuit diagramTransmittersApr 12, 2014Status-1 vote up vote down
Circuit diagram for superregenerative receiver built by GE labsRFApr 12, 2014Status-3 vote up vote down
X10 RF daughter board - receiver circuit diagramRFApr 12, 2014Status0 vote up vote down
RX3302 433MHz superregenerative receiver module circuit diagramRFApr 12, 2014Status-1 vote up vote down
Automicro RX3304 receiver module schematicRFApr 12, 2014Status1 vote up vote down
Automicro TM02 high power data transmitter module circuit diagramTransmittersApr 12, 2014Status1 vote up vote down
27MHz toy car receiver L4=9 turns, .15mm wire on 4.5mm diameter tunable ferrite coil formerModelsApr 12, 2014Status-1 vote up vote down
SAW-based 434MHz transmitter schematic with RO2101 1-port SAW resonatorTransmittersApr 12, 2014Status-1 vote up vote down
Simple VHF video transmitter / video modulator circuit diagram (not FCC approved)VideoApr 12, 2014Status0 vote up vote down
500MHz video signal transmitterVideoApr 12, 2014Status-1 vote up vote down
RF Audio transmitter circuit diagram that operates in the AM broadcast bandTransmittersApr 12, 2014Status-1 vote up vote down
49MHz walkie-talkie circuit diagram that uses only three transistorsRFApr 12, 2014Status5 vote up vote down
Superregenerative 27MHz receiverRFMar 23, 2003Status0 vote up vote down
LCD thermometer using PIC16F871Microcontroller Status0 vote up vote down
Electronic irrigation controller based on PICMicrocontroller Status-1 vote up vote down
USB digital I/O extender using a PIC18F14K50PCApr 12, 2014Status-2 vote up vote down
220V live wire-in-wall scannerTestMar 23, 2003Status-2 vote up vote down
Opendiag OBD-II Schematics & PCB Layout Opendiag OBD-II Schematics & PCB LayoutAutomotive Status-1 vote up vote down
G Strain energy absorberMiscJan 01, 2003Status1 vote up vote down
'Almost No Parts' 7-segments 12/24 Hours LED clock with PIC 16F84A or 16F628AMicrocontrollerSep 25, 2009Status-4 vote up vote down
FM Microphone micro-transmitter that is small and sensitiveTransmitters Status-1 vote up vote down
Montreal Doppler 3 DF (direction finder) unitRFApr 14, 2011Status1 vote up vote down
A PIC-based "TDOA" RDF (radio direction finder) antenna unitMicrocontrollerApr 14, 2011Status1 vote up vote down
Construction details for 30 meter rig with superhet receiver and crystal controlled transmitterRFApr 12, 2014Status0 vote up vote down
All Discrete Components 40 M transceiver with super-het receiver using no IC'sRFApr 12, 2014Status-1 vote up vote down
Versatile L tuner for end feed wire antennas that fits in an Altoids tin.RFApr 12, 2014Status0 vote up vote down
MMR-40 40 meter rig with SSB (voice) and CW (Morse code) operating modes.RFApr 12, 2014Status1 vote up vote down
Battery voltage monitor using an LM358 op-ampPowerApr 12, 2014Status-1 vote up vote down
KD1JV Digital SWR / Power MeterTestApr 12, 2014Status0 vote up vote down
An 80 meter rig for the MAS contest by KD1JVRFApr 12, 2014Status1 vote up vote down
A unique PSK transceiver, Version 2 By Steven Weber, KD1JVRFApr 12, 2014Status-2 vote up vote down
(Fairly) Simple 75M SSB rig with PTTRFApr 12, 2014Status2 vote up vote down
AM Short Wave Broadcast Receiver circuit diagramRF Status-3 vote up vote down
Low Power Antenna Analyzer and ATU Tuning AidTest Status-1 vote up vote down
Voltage boost and buck circuits using Atmel AVR Tiny13V for driving a white LEDLEDMar 09, 2012Status-2 vote up vote down
Fixed Frequency "Tuner Dipper"Test Status-3 vote up vote down
0-14 volt, 0-2 amp current limited variable power supply regulatorPower Status-2 vote up vote down
A Variable power supply with adjustable current limiting. 0-14V output up to 5A current.PowerApr 12, 2014Status0 vote up vote down
Simple WWV receiver for 10 MHz calibration signalTimingApr 12, 2014Status-1 vote up vote down
Microcontroller (AT89C2051) based tachometer (PDF)AudioNov 13, 2010Status-2 vote up vote down
GSM SMS javljalnik ALSMS-01 (page in slovenian )SMS remote control projectControlOct 07, 2009Status-1 vote up vote down
Singing Christmas tree based on Microchip PIC16F84MicrocontrollerOct 07, 2009Status-1 vote up vote down
DDS/PLL based VFO synthesizerTimingOct 07, 2009Status0 vote up vote down
Universal USB digimode interface supports CAT (Yaesu), CI/V (Icom) and RS-232 (Kenwood) units (PDF)RFOct 07, 2009Status-1 vote up vote down
50 MHz frequency counter, voltage meter & SWR/PWR indicatorMicrocontrollerJul 12, 2001Status-1 vote up vote down
Universal frequency counter & voltage meterTestOct 07, 2009Status0 vote up vote down
Convert 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radioRFJun 18, 2003Status0 vote up vote down
Simple CW identifier for a FM repeater (PDF)RFOct 07, 2009Status-1 vote up vote down
Transceiver to PC soundblaster interface for digital operating modes (PSK-31, RTTY, SSTV etc)PCOct 07, 2009Status-1 vote up vote down
6m SSB & CW QRP transceiverRFOct 07, 2009Status-1 vote up vote down
80m SSB & CW QRP superhet transceiverRFOct 07, 2009Status2 vote up vote down
Transceiver to PC interface with a hardware DTMF detector and galvanic isolation (PDF)PCOct 07, 2009Status0 vote up vote down
Pocket sized 20m (30m) CW QRP transceiverRFOct 07, 2009Status0 vote up vote down
USB / CAT (CI-V) adapter tested with FT-8900, FTB-9800, VX-7R, VX-7, FT-817 and IC-706MkIIGRFOct 07, 2009Status1 vote up vote down
Amateur weather station to APRS interface ALWXI-01MiscOct 07, 2009Status-1 vote up vote down
Collection of quartz crystal ladder filter circuit diagramsFilterOct 07, 2009Status-1 vote up vote down
Building a Digital Intervalometer - includes circuit diagram and suggested layoutPhotoMay 09, 2010Status0 vote up vote down
Serial LCD Controller using Microchip PIC16F628Microcontroller Status-1 vote up vote down
Arduino based motion triggered camera using a PIR sensorArduinoNov 13, 2010Status-3 vote up vote down
Dynamo Current and Voltage RegulatorPowerSep 21, 2006Status-2 vote up vote down
Wideband SWR meterRF Status0 vote up vote down
Spring reverb unitAudioJan 26, 2001Status-2 vote up vote down
Incoming call indicator (ZIP file)TelephoneJan 26, 2001Status0 vote up vote down
A 3m (100 MHz) small bug (ZIP file)TransmittersJan 26, 2001Status0 vote up vote down
Digital speedometer for cars with 7-segment display of speedAutomotiveJun 28, 2011Status-1 vote up vote down
PC serial port parastic mode interface for 1-wire DS18S20 and similar 1-wire temperature sensorsPCJun 28, 2011Status-1 vote up vote down
Homebrew Wired Remote for Canon EOS 350D CameraPhoto Status1 vote up vote down
Dreamcast PC serial adapterGamesOct 23, 2002Status0 vote up vote down
How to use a SCART TV as a Monitor for MAME arcade game emulatorGames Status1 vote up vote down
SCA Subcarrier Demodulator for FM broadcast stationsRF Status1 vote up vote down
ESR MeterTestMay 17, 2002Status-2 vote up vote down
Line Output / Flyback transformer testerTestMay 17, 2002Status1 vote up vote down
LED Voltage Indicator BoardLED Status-3 vote up vote down
Voice Message Recorder / Player (uses an obsolete voice recorder chip)Audio Status-1 vote up vote down
BC547 80M SSB QRP TransceiverTransmitters Status0 vote up vote down
Timer circuit based on a 14536 and 4011 CMOS chips that can be calibrated using a frequency counterTimingJan 31, 2010Status0 vote up vote down
Circuit diagram for basic alarm with delayed triggerAlarmsFeb 09, 2010Status-1 vote up vote down
General purpose portable DC power supply using rechargeable C cellsPowerFeb 05, 2010Status-2 vote up vote down
PCB board tester and RF detector circuir diagramsTestFeb 09, 2010Status-1 vote up vote down
Alarm circuit to remind you to turn off your DMM (digital multimeter)TestJan 31, 2010Status-1 vote up vote down
Circuit to enable cycling a string of Christmas lightsLightingJan 31, 2010Status0 vote up vote down
Pseudo car alarm systemAutomotiveFeb 05, 2010Status-3 vote up vote down
45 to 90Hz hum filter circuit diagramFilterSep 13, 2006Status0 vote up vote down
Sound alarm based on LM741 opamp and LM386 amplifierAmplifiersFeb 09, 2010Status-2 vote up vote down
General purchase audio preamplifier based on pair of 2N2222 transistorsPreampJan 31, 2010Status-8 vote up vote down
Audible timer that can be used as a cooking timer for roasting peanuts for exampleTimingJan 31, 2010Status-1 vote up vote down
Wireless alarm FM transmitter moduleAlarmsFeb 09, 2010Status0 vote up vote down
Switch debouncer circuits including transistor, CMOS logic and a 555 timer based designMiscJan 31, 2010Status0 vote up vote down
Percussion generator circuitsMusicFeb 09, 2010Status0 vote up vote down
Bench power supply that allows a number of varying output voltages to be preset. Includes PCB layoutPowerFeb 26, 2010Status-2 vote up vote down
Small audio amplifier based on LM386AmplifiersJan 31, 2010Status-4 vote up vote down
Function generator based on 555 timer and three 2N2222 transistorsTestFeb 05, 2010Status-3 vote up vote down
Interesesting circuits using diodes ideal for education or introductory courses on electronicsMiscFeb 20, 2010Status-1 vote up vote down
Sequential flashing arrow circuit using a 4017, also includes a PCB layoutLEDFeb 26, 2010Status0 vote up vote down
Selection of run circuits to experiment with the 4017 CMOS decade counter chipMiscFeb 26, 2010Status-2 vote up vote down
Notes on using LEDs and various LED driver circuit diagramsLEDFeb 26, 2010Status2 vote up vote down
Multi-trace scope display that allows up to 4 channels to be viewed on a single oscilloscope channelTestFeb 26, 2010Status-1 vote up vote down
Small circuit and PCB layout for recording to PC Sound Monitor / Pre-ampPCFeb 26, 2010Status-1 vote up vote down
FM Microphone transmitter / FM buf circuit diagramTransmittersJan 31, 2010Status0 vote up vote down
Model Train Diesel & Horn Sound ModuleModelsMar 30, 2010Status0 vote up vote down
Magentic phono cartridge phono preamp circuit diagramPreampFeb 05, 2010Status-4 vote up vote down
Power supply metering circuits for measuring both voltage and currentPowerFeb 09, 2010Status-5 vote up vote down
Cicuit diagram for super long range microphone for use with a shotgun microphone or parabolic dishAudioFeb 20, 2010Status-2 vote up vote down
Fuse or line monitor that will check the status of up to six fuses including a PCB layoutAlarmsFeb 20, 2010Status-1 vote up vote down
Variety of applications using a CMOS 4001 2-input NOR gate including a PCB layoutMiscFeb 20, 2010Status0 vote up vote down
Select of interesting electronic circuits that require only a single transistor ideal for educationMiscFeb 20, 2010Status0 vote up vote down
Small selection of useful circuitsMiscFeb 09, 2010Status-2 vote up vote down
Variety of simple motor control circuit diagrams using SCR or TRIACControlFeb 20, 2010Status-1 vote up vote down
Super mixer with microphone input / amplifier including a PCB layoutAmplifiersFeb 20, 2010Status-2 vote up vote down
Selection of 14 oscillator circuits include sinewave, audio, logic and LED flashersTimingFeb 20, 2010Status-1 vote up vote down
Jeopardy game circuit diagram using three CMOS logic chipsGamesFeb 09, 2010Status1 vote up vote down
Selection of audio preamplifiers including circuits suitable for battery operationPreampJan 31, 2010Status-4 vote up vote down
DDS from 1-60 MHz with built-in amplifier and variable output level using Analog Devices AD9851Test Status-2 vote up vote down
Ericsson phone to PC serial port interfacePCNov 29, 2002Status-3 vote up vote down
Network car controller provides functions for remote door locks, headlight reminder, and car finderAutomotiveMay 16, 2010Status-1 vote up vote down
Emergency power systemPowerMay 16, 2010Status-3 vote up vote down
Digital bench power supply based on a PIC16F870PowerMay 24, 2010Status-2 vote up vote down
Candle simulator based on a PIC12F675 microcontrollerLightingMay 16, 2010Status1 vote up vote down
Magnetic card reader to PC RS-232 port interface based on a PIC12F675 microPCMay 24, 2010Status0 vote up vote down
Cat toy using a PIC12F675 and a small weighted motor to keep your cat amusedGamesMay 24, 2010Status0 vote up vote down
Dirt cheap video using a PIC16F819 microcontrollerMicrocontrollerMay 16, 2010Status-1 vote up vote down
Dremel drill speed controllerControlMay 16, 2010Status0 vote up vote down
Talking Egyption frog boxGamesMay 24, 2010Status0 vote up vote down
Talking fish hack using a PIC16F819 microcontrollerMicrocontrollerMay 16, 2010Status-1 vote up vote down
Furby Resurrection - Project that replaces the electronics in a Furby with new custom electronicsGamesMay 24, 2010Status0 vote up vote down
PWM Heater fan controller based on PIC12F675ControlMay 24, 2010Status-1 vote up vote down
Hexbot robot based on a PIC including source code and circuit diagramModelsMay 16, 2010Status-3 vote up vote down
433MHz super remote control using a PIC12F683 to boost rangeTransmittersMay 24, 2010Status0 vote up vote down
Home theater systemAudioMay 24, 2010Status-3 vote up vote down
Beam robot / insect based on a PIC16F818 microcontrollerModelsMay 24, 2010Status0 vote up vote down
Infrared object detector using a PIC12F629 microcontrollerIRMay 16, 2010Status-1 vote up vote down
Isolated oscilloscope probeTestMay 16, 2010Status-1 vote up vote down
Telephone line simulator ideal for testing phone interface projectsTelephoneMay 24, 2010Status0 vote up vote down
Lithium Ion Battery Charger based on a PIC micro including circuit diagram and source codePowerMay 24, 2010Status0 vote up vote down
Marshmallow Bazooka with a PIC12F615 based capacitor discharge ignition systemMiscMay 16, 2010Status0 vote up vote down
Colour Organ based on a PIC16F84 microcontroller including schematics and source codeMusicMay 24, 2010Status3 vote up vote down
Touch sensistive touchpad based on a PIC16F627A microMiscMay 24, 2010Status-1 vote up vote down
Self-powered phone messenger based on a PIC16C819 microcontrollerTelephoneMay 24, 2010Status0 vote up vote down
Phone call interceptor to stop unsolicited phone callsTelephoneMay 16, 2010Status0 vote up vote down
Telephone call screener with voiceTelephoneMay 24, 2010Status1 vote up vote down
Remote RF transmitter based on PIC12F675 or PIC12F629TransmittersMay 24, 2010Status-1 vote up vote down
Remote infrared terminal for projects requiring IR communicationsIRMay 24, 2010Status0 vote up vote down
RS-232 to TTL level translatorPCMay 16, 2010Status-1 vote up vote down
DIY flying saucer / UFO using a PIC microcontrollerGamesMay 16, 2010Status0 vote up vote down
Solar charge controller based on a PIC microcontroller including schematic and source codeSolarMay 16, 2010Status0 vote up vote down
SD card interface for PIC microcontroller including schematic and source codeMicrocontrollerMay 16, 2010Status-2 vote up vote down
Function Generator Sine / Triangle / Square / Saw / Burst Sweep Noise based on PIC16F870TimingMay 16, 2010Status-1 vote up vote down
Circuit monitoring device logs for over 10 days and can log up to 32k events both digital and analogData AcquisitionMay 24, 2010Status0 vote up vote down
Superprobe handheld test device based on a PIC16F870TestMay 24, 2010Status2 vote up vote down
Speech Synthesizer Development System using a PIC microcontrollerMicrocontrollerMay 16, 2010Status1 vote up vote down
Toy car hack to turn it into a synthetic rodentModelsMay 24, 2010Status0 vote up vote down
PIC micro programmer that runs under MAC, Win98, XP, Vista, DOS, Linux, etcProgrammersMay 24, 2010Status1 vote up vote down
Video switcher to allow monitoring of multiple video cameras using a single monitorVideoMay 24, 2010Status1 vote up vote down
Low cost video motion detection using a PIC16F819 and an LM339VideoMay 24, 2010Status-1 vote up vote down
YoYo enhancement device using a PIC12F629 to provide LED lighting effectsLEDMay 24, 2010Status-1 vote up vote down
Electric cockroach zapperMiscMay 24, 2010Status-2 vote up vote down
Programmer PIC16F84,12C50x and EEPROM 24CxxProgrammersAug 14, 2002Status0 vote up vote down
Build an inexpensive Hall effect GaussmeterTest Status-1 vote up vote down
Design for a slightly more expensive GaussmeterTest Status-1 vote up vote down
Home-Built Magnetic LevitatorMisc Status0 vote up vote down
Project for experimenting with magnetic levitationMisc Status1 vote up vote down
Adaptive Windscreen Wiper ControlAutomotiveApr 14, 2003Status-1 vote up vote down
Portable iPod chargerPDA Status0 vote up vote down
Ultrasound detectorMiscSep 13, 2006Status-1 vote up vote down
IC tone control preamplifier using single 741 opampPreampJul 03, 2011Status-5 vote up vote down
1KHz 4th order Butterworth filter using LT1367 quad operational amplifierFilterJul 03, 2011Status0 vote up vote down
1.5 volt FM transmitter circuit diagramTransmittersJul 03, 2011Status-2 vote up vote down
10-30 watt stereo audio amplifier circuitAmplifiersJul 03, 2011Status8 vote up vote down
118MHz to 136MHz aircraft receiver circuit diagramRFJul 03, 2011Status3 vote up vote down
12V 300W 4 channel car amplifier schematic diagramAutomotiveJul 03, 2011Status3 vote up vote down
1300MHz - 1500MHz transmitter with 20 - 50mW output powerTransmittersJul 03, 2011Status0 vote up vote down
1300MHz - 1500MHz antenna with amplifier based on two MAR-8 RF amplifiersRF_AmplifierJul 03, 2011Status1 vote up vote down
15W mono car amplifier using TA7227PAutomotiveJul 03, 2011Status2 vote up vote down
Shortwave received circuit diagramRFJul 03, 2011Status-2 vote up vote down
Two transistor audio preamplifier with volume controlPreampJul 03, 2011Status0 vote up vote down
20KHz Butterworth active filter using Linear Technology LT1124, LT1355 or LT1169FilterMay 25, 2012Status0 vote up vote down
2W / 4W audio amplifier using pair of LA4100, LA4101 or LA4102 modulesAmplifiersMay 25, 2012Status-6 vote up vote down
455KHz oscillator using FET and 455KHz IF transformerTimingMay 25, 2012Status1 vote up vote down
6W mono car amplifier using BA521 or BA532 amplifier moduleAutomotiveMay 25, 2012Status0 vote up vote down
Basic logarithmic amplifier using op-amp and NPN transistorPreampJul 03, 2011Status-5 vote up vote down
Beat frequency oscillator for AM/SW radio receiversRFMay 25, 2012Status0 vote up vote down
Direct conversion 7MHz receiver using NE602RFMay 25, 2012Status0 vote up vote down
Low voltage microphone preamplifier using LM10PreampMay 25, 2012Status0 vote up vote down
Micro TV transmistterVideoMay 25, 2012Status-2 vote up vote down
Mono audio preamplifier using single 2SC732 transistorPreampMay 25, 2012Status-6 vote up vote down
Relay interface to R/C receiversModelsMay 25, 2012Status-1 vote up vote down
Small TV transmitter for CCTV observationVideoMay 25, 2012Status1 vote up vote down
VCR head amplifier testerTestMay 25, 2012Status-1 vote up vote down
Video line receiver using AD818VideoMay 25, 2012Status-1 vote up vote down
Wireless guitar transmitterMusicMay 25, 2012Status-7 vote up vote down
Wireless microphone using 741 opamp and 2N3904TransmittersMay 25, 2012Status0 vote up vote down
WWV receiverRFMay 25, 2012Status2 vote up vote down
Casio calculator interface schematicPDASep 10, 2006Status1 vote up vote down
Conrad Electronics MM3610D multimeter cable pinoutTestSep 10, 2006Status-2 vote up vote down
1.5 GHz PLL Frequency SynthesizerRFApr 10, 2014Status0 vote up vote down
Tiny EEG interface schematicMedical Status-1 vote up vote down
OpenEEG open hardware EEG projectMedical Status-2 vote up vote down
Fitting a JTAG interface to an iPAQ 3600PDASep 10, 2006Status0 vote up vote down
Diode laser electronic circuits for atom opticsLaser Status-2 vote up vote down
Build Your Own Video-Rate 2-photon MicroscopeMiscSep 25, 2009Status0 vote up vote down
LED driving and controlling methods including constant current drivers and PWM brightness controlLEDJul 11, 2012Status-1 vote up vote down
Touch senstor based on Atmel AT90S2313Microcontroller Status0 vote up vote down
VHF/UHF TV modulatorVideoNov 16, 2002Status-1 vote up vote down
Programming hardware and softrware for 14-bit FLASH PIC microcontrollersProgrammersFeb 25, 2011Status0 vote up vote down
Single cell LED flasher with two-year battery life (LM3909 replacement)LED Status-1 vote up vote down
Volvo 164 electric fan thermostatAutomotiveFeb 25, 2011Status-1 vote up vote down
RS232 to RS485 converter schematic to connect PC to RS485 networkPCApr 09, 2010Status-1 vote up vote down
RS232 serial to USB converter cable circuit schematicPC Status-1 vote up vote down
Sony RS-422 ADAT sync cable pinoutMiscSep 10, 2006Status0 vote up vote down
Mac to HP48 cable pinoutPCSep 10, 2006Status-1 vote up vote down
Digital cameras (AGFA, Olympus) to PC (COM) cable pinoutPhotoSep 10, 2006Status0 vote up vote down
Garmin Foretrex 101,201, Forerunner 101,201 to Serial DB9 cable schematic pinoutMiscSep 10, 2006Status0 vote up vote down
Apple iPod and iPhone dock pinoutPDASep 13, 2006Status-1 vote up vote down
Palm Pilot, Palm III, V, VII, VIIx, Handera interface port pinoutPDASep 13, 2006Status0 vote up vote down
Car OBDII diagnostic interface cable schematic pinoutAutomotiveSep 10, 2006Status-2 vote up vote down
Car OBD II J1850 PWM, J1850 VPW, ISO-9141 cables schematic pinoutAutomotiveSep 10, 2006Status0 vote up vote down
Simple DTMF Repeater Controller using PIC16F84Misc Status-2 vote up vote down
LCD clock based on AVR Attiny2313Microcontroller Status-2 vote up vote down
Music player built on microcontroller AT91SAM7S256 with ARM coreMusic Status-1 vote up vote down
Build a Simple Bat DetectorMiscJan 08, 2014Status1 vote up vote down
Various radio control schematicsModels Status-3 vote up vote down
Linear constant current source dimmer for a white 24-LED arrayLEDMar 03, 2011Status2 vote up vote down
Simple current limiting for LED flashlightsLEDMar 03, 2011Status0 vote up vote down
Single-Wire-Telephones for caves and minesTelephoneMar 03, 2011Status0 vote up vote down
Transverter for Converting SSB CB to LF for Thru-the-Earth Voice CommunicationsRFMar 03, 2011Status2 vote up vote down
A simple and inexpensive laser power meter (PDF)LaserFeb 21, 2013Status-1 vote up vote down
101 AT Keyboard to ASCII Decoder using 68HC705J1A MCUMicrocontrollerJan 26, 2001Status-1 vote up vote down
Traffic light controller using an Arduino microcontrollerArduinoAug 26, 2010Status-2 vote up vote down
Simple ADS-B aircraft transponder decoder based on a PIC18F2550 microcontrollerRFDec 09, 2010Status2 vote up vote down
PIXpand - TI calculator to Playstation memory card interfaceMicrocontrollerJul 12, 2001Status0 vote up vote down
Constant current LED driver schematic using a pair of BC547 transistorsLEDJul 11, 2012Status-1 vote up vote down
Simple laser communicatorLaserJun 09, 2002Status-1 vote up vote down
Arduino UNO based CW decoderArduinoJun 24, 2015Status-1 vote up vote down
PIC 18 programmer (PIC18F458, PIC18F452, PIC18C252, PIC16C745, PIC18F6620, PIC18F6720)ProgrammersJun 06, 2003Status0 vote up vote down
Game boy camera PC serial interfacePCSep 13, 2006Status-1 vote up vote down
Build a synchronous clock locked to the mains frequencyTimingAug 18, 2009Status0 vote up vote down
Simple Class A Amplifier - 10W audio outputAmplifiersJan 22, 2010Status-3 vote up vote down
Better Volume (and Balance) control circuit diagramsAudioApr 14, 2010Status-1 vote up vote down
Low Noise Microphone PreamplifierPreampJun 04, 2010Status-3 vote up vote down
Bridging Adapter For Audio Power AmplifiersAmplifiersJan 29, 2010Status-7 vote up vote down
Audio MillivoltmeterTestApr 14, 2010Status0 vote up vote down
'A' Weighting Filter For Audio MeasurementsFilterSep 13, 2006Status0 vote up vote down
Simple surround sound decoder circuit schematicAudioApr 14, 2010Status-1 vote up vote down
Stereo Width ControllersMusicMay 07, 2010Status-1 vote up vote down
Power Amplifier Clipping Indicator Circuit DiagramAmplifiersJan 29, 2010Status-3 vote up vote down
Collection of phono preamplifier circuitsPreampApr 21, 2010Status6 vote up vote down
Digital Delay Unit For Surround SoundMusicMay 07, 2010Status-2 vote up vote down
100W Guitar Amplifier Mk II circuit diagramMusicJan 29, 2010Status-5 vote up vote down
Parametric And Sub-Woofer EqualiserAudioApr 14, 2010Status-2 vote up vote down
High Quality Audio MixerAudioMar 17, 2010Status-3 vote up vote down
Simple Car Preamplifier and Artificial EarthPreampJan 29, 2010Status-2 vote up vote down
Loudspeaker Protection and MutingAudioJan 29, 2010Status-2 vote up vote down
Spring Reverb Unit For Guitar or KeyboardsMusicApr 14, 2010Status0 vote up vote down
Audio Signal Detecting Auto Power-On UnitControlMar 30, 2010Status1 vote up vote down
Soft-Start Circuit For Power AmpsAmplifiersMar 30, 2010Status-1 vote up vote down
Mains Power Load Sensing Automatic SwitchControlMar 30, 2010Status-1 vote up vote down
Thermo-Fan to keep your amplifier or other equipment coolControlMar 30, 2010Status-1 vote up vote down
Guitar Vibrato Unit Circuit DiagramMusicApr 14, 2010Status1 vote up vote down
Microphone Circuit Test OscillatorTestApr 14, 2010Status0 vote up vote down
Distortion analyser circuit diagramTestApr 14, 2010Status-2 vote up vote down
VU And PPM Audio MeteringAudioMay 07, 2010Status-2 vote up vote down
Variable Amplifier ImpedanceAmplifiersMar 30, 2010Status-1 vote up vote down
The ESP SIM (Sound Impairment Monitor)TestApr 14, 2010Status-2 vote up vote down
Linkwitz Cosine Burst GeneratorTestApr 14, 2010Status0 vote up vote down
Multiple Feedback Bandpass FilterFilterNov 01, 2002Status0 vote up vote down
High quality audio preamplifier (OPA2134)PreampSep 13, 2006Status-8 vote up vote down
Automatic Charger for Battery Operated Hi-Fi PreampsPreampJun 17, 2003Status0 vote up vote down
Capacitance to Voltage conversionMisc Status0 vote up vote down
LED dice project based on 555 timer and CD4017 decade counterGames Status0 vote up vote down
CMoy pocket headphone amplifierAmplifiers Status-4 vote up vote down
Biasing Op-Amps into Class AMiscJan 01, 2003Status0 vote up vote down
Laser high-voltage power supplyLaserOct 06, 2006Status0 vote up vote down
THE FOX - 40 milliwatt transmitterTransmittersApr 14, 2011Status0 vote up vote down
THE FOX 750 - 750 milliwatt transmitterTransmittersApr 14, 2011Status0 vote up vote down
Active RF antennuatorRFApr 14, 2011Status2 vote up vote down
FOX BOX - Transmitter controllerTransmittersApr 14, 2011Status0 vote up vote down
Amplified field strength meter / RF snifferTestApr 14, 2011Status-2 vote up vote down
THE FOX - 250mw transmitter with timerTransmittersApr 14, 2011Status2 vote up vote down
Simple Time-Difference-Of-Arrival RDFRFApr 14, 2011Status0 vote up vote down
555 Time-Difference-Of-Arrival RDFRFApr 14, 2011Status-1 vote up vote down
PIC-Bot II using Microchip PIC16LF84Models Status0 vote up vote down
Arduino MIDI interface (Arduino MIDI Drum Kit and Spooky Sound Trigger)ArduinoAug 26, 2010Status-1 vote up vote down
Solar robotsSolarNov 16, 2002Status-1 vote up vote down
Bleeper box for time referenceMiscMay 01, 2004Status-1 vote up vote down
3 in one tester (audio, tone generator, diode/circuit tester)Test Status-3 vote up vote down
50MHz converter project based on a NE602/SA602/NE612RF Status0 vote up vote down
AF variable frequency generator using 555 ICTiming Status0 vote up vote down
Regulatable audio amplifier using a 741opampAmplifiers Status1 vote up vote down
HF/6M Antenna Tuner Preselector and Antenna SwitcherRF Status0 vote up vote down
Bass EQ pre-amp correction for high impedance ceramic crystal pickupAmplifiers Status-3 vote up vote down
300/1200 baud BAYCOM MODEM (revision and improved)PC Status-1 vote up vote down
Direct Crystal radio receiver examplesRF_Amplifier Status2 vote up vote down
Crystal switcher using diodesTiming Status1 vote up vote down
MW Enhanced Crystal Receiver using 741 ICRF Status-2 vote up vote down
455 Khz MF to AF converter used for DRM reception in a Yaesu FRG-100 receiverRF Status1 vote up vote down
Emergency light flasher schematicLighting Status-1 vote up vote down
Sensitive LW/MW/SW Shortwave general coverage receiverRF Status-1 vote up vote down
HAMCOM (SSTV, RTTY, FAX...) modem using PC-speaker for TXPC Status-1 vote up vote down
10 meter (28MHz) band RF amplifierRF_Amplifier Status1 vote up vote down
12 watt audio amplifier with tone using TDA1020Amplifiers Status0 vote up vote down
5 watt audio amplifier using TDA1010Amplifiers Status-3 vote up vote down
Low frequency / audio frequency dB output meterAudio Status-1 vote up vote down
Basic low frequency preamplifier circuitsPreamp Status2 vote up vote down
Microphone pre-amp with high emphasisPreamp Status-4 vote up vote down
MW/SW Radio receiverRF Status0 vote up vote down
Bipolar transistor RF mixerRF Status-1 vote up vote down
IC oscillator 1...30MHz using 74LS04 chipTiming Status2 vote up vote down
Simple AF-oscillator / signal generator using pair on 2N2222 transistorsTiming Status1 vote up vote down
HF/VHF mini portable antenna tunerRF Status0 vote up vote down
Microphone preamp for portable transceiversPreamp Status-1 vote up vote down
Wideband VHF/UHF/SHF 22dB RF preamp with MAR-6 or MAR-8 (MSA-0885)RF_Amplifier Status-3 vote up vote down
PTT and/or soundcard interfacePC Status0 vote up vote down
PTT and soundcard interface for the TM255/455PC Status0 vote up vote down
HF 10 watt amplifier for 18MHz using a 2SC1969/2SC1944 transistorRF_Amplifier Status0 vote up vote down
RF Power meter / dummy loadRF Status1 vote up vote down
HAMCOM (SSTV, RTTY, FAX...) modem using serial audio for TXPC Status0 vote up vote down
HAMCOM & SoundCard MODEM using serial- or soundcard audioPC Status-1 vote up vote down
SWR bridge covering HF to VHFRF Status1 vote up vote down
Active bandpass filter with TDA2320AFilter Status1 vote up vote down
1 Watt audio amp using a TDA7052Amplifiers Status-1 vote up vote down
TM-441 9600bps packet modificationPC Status-1 vote up vote down
1 Watt AM transmitter for the 10 meter band (28MHz)Transmitters Status1 vote up vote down
12-meterband QRP AM oscillator transmitter using a 2N2219 transistorTransmitters Status-1 vote up vote down
500mW AM transmitter for the 20 meter band (14MHz)Transmitters Status-1 vote up vote down
VHF 6 Meterband RF amplifierRF_Amplifier Status-1 vote up vote down
HF/VHF portable antenna tunerRF Status-1 vote up vote down
90S2313 AVR Robot BoardMicrocontrollerMay 01, 2004Status1 vote up vote down
A selection of robotics projectsModelsJun 09, 2002Status0 vote up vote down
Digital clock based on 74 series logicTiming Status0 vote up vote down
LH0032 video amplifierVideoOct 24, 2002Status-1 vote up vote down
LM359N video amplifierVideoOct 24, 2002Status-1 vote up vote down
ATmega8 based TNC with GPS and WX supportMicrocontrollerMar 27, 2009Status-2 vote up vote down
Atmel AVR 90s2313 based POCSAG encoder (ZIP file)MicrocontrollerMar 27, 2009Status1 vote up vote down
Atmel 90s2313 based TNCMicrocontrollerMar 27, 2009Status0 vote up vote down
ATmega48 based Nixie ClockTubeMar 27, 2009Status0 vote up vote down
POCSAG encoder/decoder (Zip file)MicrocontrollerJul 10, 2002Status-1 vote up vote down
Simple alarm with telephone dialler interfaceTelephoneMar 27, 2009Status1 vote up vote down
In-circuit electrolytic capacitor checkerTestMar 27, 2009Status-2 vote up vote down
Logic probe with pulserTestMar 27, 2009Status-2 vote up vote down
Telephone line simulatorTelephoneMar 05, 2001Status2 vote up vote down
Making your own RS-60E3 Remote Control for Canon EOS camerasPhoto Status-1 vote up vote down
Home made PBX / PABXTelephoneJun 17, 2003Status1 vote up vote down
Headphone amplifier based on 12AX7 tubesTube Status-1 vote up vote down
Two nixie display clockTube Status1 vote up vote down
Pocket Ignignokt LED displayLED Status1 vote up vote down
VFD (vacuum flourescent display) clockTube Status0 vote up vote down
Single-digit Nixie clockTube Status0 vote up vote down
Oscilloscope CRT ClockTube Status0 vote up vote down
Weston Voltmeter ClockTiming Status0 vote up vote down
Using a PC power supply as a benchtop power supplyPC Status-1 vote up vote down
Digibox interface circuit diagramIRAug 09, 2002Status0 vote up vote down
Six-channel Mixer and AmplifierAmplifiersJan 31, 2003Status-1 vote up vote down
Audio Signal SourceAudioOct 30, 2002Status-1 vote up vote down
Random noise generatorMiscJan 26, 2001Status0 vote up vote down
Analog pulse counterMiscAug 12, 2001Status0 vote up vote down
Analog opto-isolatorMiscAug 12, 2001Status0 vote up vote down
Voltage controlled amplifierAmplifiersAug 12, 2001Status0 vote up vote down
Current loop interfaceControlAug 12, 2001Status-1 vote up vote down
Audio graphic equaliserAudioAug 12, 2001Status-2 vote up vote down
Intercom preampPreampAug 12, 2001Status0 vote up vote down
Electric field & leakage detectorTestAug 12, 2001Status-2 vote up vote down
Pulse width modulators (PWM)MiscAug 12, 2001Status0 vote up vote down
30W ultra-low distortion audio power amplifierAmplifiersJan 22, 2010Status-4 vote up vote down
Pulse width to voltage converterMiscAug 12, 2001Status-1 vote up vote down
Ultrasonic remote control & alarm systemAlarmsAug 12, 2001Status-2 vote up vote down
Grand Cherokee Off-Highway LightsAutomotive Status-1 vote up vote down
Flashing LED circuit using 555 timerLEDJul 03, 2011Status0 vote up vote down
Engine control unit schematicsAutomotiveNov 16, 2002Status0 vote up vote down
3 Channel Spectrum AnalyzerAudioSep 01, 2009Status-1 vote up vote down
3 Watt FM Transmitter circuit diagramTransmittersSep 01, 2009Status1 vote up vote down
6V to 12V ConverterPower Status-2 vote up vote down
AC Motor Speed ControllerControlSep 01, 2009Status-1 vote up vote down
Aircraft Radio Communications ReceiverRFSep 01, 2009Status-1 vote up vote down
Air flow detector using an incandescent lamp to detect airflowMisc Status0 vote up vote down
Wire Loop Alarm using 4001UBE Quad NOR GateAlarmsSep 01, 2009Status-1 vote up vote down
Circuit diagram for 8 watt audio ampAmplifiersJan 26, 2001Status1 vote up vote down
22 Watt Audio Amplifier using TDA1554 two channel audio amp chipAmplifiersSep 01, 2009Status8 vote up vote down
50 Watt Amplifier circuit diagramAmplifiersSep 01, 2009Status-4 vote up vote down
Fantastic Atom ExpanderLEDSep 01, 2009Status1 vote up vote down
Car Alarm Arming Horn Beep CancellerAutomotiveSep 01, 2009Status0 vote up vote down
Black LightLightingSep 01, 2009Status1 vote up vote down
Portable CD Player Adapter For CarAutomotiveSep 01, 2009Status-2 vote up vote down
Car Battery ChargerAutomotiveSep 01, 2009Status-3 vote up vote down
Automatic 12V Lead Acid Battery ChargerPowerSep 01, 2009Status0 vote up vote down
LED ChaserLEDSep 01, 2009Status0 vote up vote down
Simple Two Speed Contactor DC Motor ControllerControlSep 01, 2009Status0 vote up vote down
Digital Keypad Combination LockAlarmsSep 01, 2009Status-2 vote up vote down
Computer Controlled Frequency Counter/Logic ProbePCSep 01, 2009Status-1 vote up vote down
Simple Colour OrganMusicSep 01, 2009Status1 vote up vote down
7 Segment LED CounterLEDSep 01, 2009Status1 vote up vote down
Crystal RadioRFSep 01, 2009Status1 vote up vote down
Circuits to computerize your room/housePCSep 01, 2009Status-2 vote up vote down
TRIAC Light DimmerLightingSep 01, 2009Status0 vote up vote down
12VDC Fluorescent Lamp DriverLightingSep 01, 2009Status1 vote up vote down
FM Transmitter with range of about 300 feetTransmittersSep 01, 2009Status0 vote up vote down
Guitar Fuzz EffectMusicSep 01, 2009Status0 vote up vote down
Automatic Headlight Brightness SwitchAutomotiveSep 01, 2009Status-2 vote up vote down
Solid State Tesla Coil/High Voltage GeneratorPowerSep 01, 2009Status-1 vote up vote down
Simple Parallel (Printer) Port InterfacePCSep 01, 2009Status-1 vote up vote down
12V to 120V Inverter circuit diagramPowerSep 01, 2009Status-4 vote up vote down
Infa-Red Remote ControlIRSep 01, 2009Status0 vote up vote down
IR Remote Control JammerIRSep 01, 2009Status0 vote up vote down
LASER Power SupplyLaserSep 01, 2009Status3 vote up vote down
LASER Transmitter/ReceiverLaserSep 01, 2009Status0 vote up vote down
LED ThermometerLEDSep 01, 2009Status1 vote up vote down
Simple Lie DetectorMiscSep 01, 2009Status0 vote up vote down
Light/Dark Detector drives a relayControlSep 01, 2009Status-1 vote up vote down
Low Voltage AlarmMiscSep 01, 2009Status0 vote up vote down
Video Stabilizer/MacroVision RemovalVideoSep 01, 2009Status-3 vote up vote down
FET Audio MixerAudioSep 01, 2009Status-1 vote up vote down
Microphone MixerAudioSep 01, 2009Status-2 vote up vote down
Pulse Width Modulation DC Motor ControllerControlSep 01, 2009Status-1 vote up vote down
8 Note Tune PlayerMusicSep 01, 2009Status0 vote up vote down
Colour (Sound) OrganMusicSep 01, 2009Status0 vote up vote down
Ringing Phone Light FlasherTelephoneSep 01, 2009Status0 vote up vote down
Phone Busy IndicatorTelephoneSep 01, 2009Status0 vote up vote down
FM Telephone BugTelephoneSep 01, 2009Status0 vote up vote down
Cut Phone Line DetectorTelephoneSep 01, 2009Status0 vote up vote down
Simple Phone Tap CircuitTelephoneSep 01, 2009Status0 vote up vote down
Telephone Hold ButtonTelephoneSep 01, 2009Status0 vote up vote down
Telephone RecorderTelephoneSep 01, 2009Status0 vote up vote down
Simple Polarity TesterTestSep 01, 2009Status-1 vote up vote down
Water Detector With Sump/Bilge Pump ControllerControlSep 01, 2009Status-1 vote up vote down
Pine Racecar Victory JudgeGamesSep 01, 2009Status0 vote up vote down
Op Amp RadioRF_AmplifierSep 01, 2009Status-1 vote up vote down
Rain DetectorMiscSep 01, 2009Status0 vote up vote down
Time Delay RelayControlSep 01, 2009Status-1 vote up vote down
Time Delay Relay IIControlSep 01, 2009Status1 vote up vote down
Remote Telephone Bell RingerTelephoneSep 01, 2009Status0 vote up vote down
Simple Servo Controller using 555 TimerControlSep 01, 2009Status-3 vote up vote down
Flash Slave TriggerPhotoSep 01, 2009Status0 vote up vote down
Stepper Motor Controller using 4027 flip-flop and 4070 XOR gateControlSep 01, 2009Status-1 vote up vote down
Mono To Stereo Synthesizer / SimulatorAudioSep 01, 2009Status0 vote up vote down
Electronic StethoscopeMedicalSep 01, 2009Status2 vote up vote down
Strobe lightLightingJan 26, 2001Status0 vote up vote down
Adjustable Strobe LightLightingSep 01, 2009Status-1 vote up vote down
Basic Power SupplyPowerSep 01, 2009Status2 vote up vote down
High Current Power SupplyPowerSep 01, 2009Status-1 vote up vote down
Dual Polarity Power SupplyPowerSep 01, 2009Status-1 vote up vote down
High Voltage High Current Power SupplyPowerSep 01, 2009Status-3 vote up vote down
Transformerless Power SupplyPowerSep 01, 2009Status-5 vote up vote down
Fixed Voltage Power SupplyPowerSep 01, 2009Status-1 vote up vote down
Wireless Auto TachometerAutomotiveSep 01, 2009Status0 vote up vote down
Tone Control using TDA1524A Tone Control ICAudioSep 01, 2009Status-1 vote up vote down
Simple Transistor OrganMusicSep 01, 2009Status0 vote up vote down
Touch Switch using 4011 CMOS NAND Gate ICControlSep 01, 2009Status-2 vote up vote down
Video Activated RelayVideo Status0 vote up vote down
Voltage Inverter using 555 TimerPowerSep 01, 2009Status-2 vote up vote down
Voltage Inverter using LM380 audio amplifier ICPowerSep 01, 2009Status-3 vote up vote down
Digital Volume Control using DS1669 Digital Pot ICAudioSep 01, 2009Status-1 vote up vote down
Sound Level MeterAudioSep 01, 2009Status-1 vote up vote down
89C2051 microcontroller programmerProgrammers Status0 vote up vote down
JFET Bass PreampPreamp Status-1 vote up vote down
Dual power supplyPowerJan 31, 2003Status-1 vote up vote down
Magnetic levitation deviceMiscAug 14, 2002Status0 vote up vote down
Tesla power receiverMiscJan 06, 2002Status0 vote up vote down
Class B series modulatorRF Status-1 vote up vote down
The KD2BD Pacsat ModemPCJul 10, 2002Status-1 vote up vote down
SHARP palm-top/hand-held to RS232 serial converterPDA Status0 vote up vote down
1.9 Kilojoule Coil GunMiscNov 16, 2010Status-1 vote up vote down
20kV Digital High Voltage MeterTestNov 16, 2010Status1 vote up vote down
Build your own radio controlled switch from a cordless telephoneTelephoneNov 16, 2010Status0 vote up vote down
A spark throwing tesla coil made entirely of garbageMiscNov 16, 2010Status1 vote up vote down
Measuring Acceleration Using a PIC Microcontroller (ADXL202 + PIC16F84A)MicrocontrollerJan 09, 2010Status-1 vote up vote down
PIC serial communications tutorial, includes circuit diagram and PIC16F84 assembler codeMicrocontrollerJan 09, 2010Status-1 vote up vote down
Eight simple power supplies for your workbench (mainly vacuum tube based)TubeApr 10, 2014Status0 vote up vote down
Build a Crystal Set (simple AM radio receiver)RFApr 10, 2014Status2 vote up vote down
Filter Choke AnalyzerTestApr 10, 2014Status-1 vote up vote down
Vacuum Tube Grid Leak Detector: Needs an AmplifierTubeApr 10, 2014Status0 vote up vote down
A Load Box for testing power suppliesTestApr 10, 2014Status-2 vote up vote down
Low resistance adapter for a DMM (digital multimeter)TestApr 10, 2014Status0 vote up vote down
Vacuum Tube Plate Detector: Needs an AmplifierTubeApr 10, 2014Status1 vote up vote down
Precision Frequency Control for AM Radios - A Frequency Synthesized Local OscillatorRFApr 10, 2014Status0 vote up vote down
Miniature SWR / RF power meter circuitTestFeb 15, 2014Status-2 vote up vote down
Home Brew Compass SensorData AcquisitionApr 27, 2003Status-1 vote up vote down
Higher Order Analog Butterworth Filter Designs, includes on-line filter calculatorFilterJan 16, 2010Status-1 vote up vote down
SWTP PR-40 Printer Interface SchematicsPCSep 10, 2006Status-2 vote up vote down
Interfacing Sony control stick to EmpegGamesJun 09, 2002Status0 vote up vote down
Negative voltage generatorPowerAug 12, 2001Status1 vote up vote down
Basic Homebuilt Discrete DTL gate circuits (Diode Transistor Logic)Misc Status0 vote up vote down
Electronic shutter release with ultrasonic remote controlPhoto Status0 vote up vote down
Lazer Tag Equipment ModificationsMiscMar 23, 2003Status0 vote up vote down
A Serial Infrared Remote ControllerPCJan 26, 2001Status0 vote up vote down
Driving high-power loads with a microprocessorMicrocontroller Status-1 vote up vote down
Control your camera (Canon DSLR) with your Palm PDAPhoto Status0 vote up vote down
Simple 10 bit DAC for the Arduino using TLC274 opampArduinoJun 07, 2011Status-1 vote up vote down
Connect a NTC with a wheatstone bridge to a normal AD-InputData Acquisition Status1 vote up vote down
IDE interface to a Microchip PIC16F877 microcontrollerMicrocontroller Status0 vote up vote down
Inexpensive APRS Weather StationMiscAug 14, 2002Status0 vote up vote down
1381 solar engineSolarNov 16, 2002Status0 vote up vote down
Collection of BEAM robot circuitsModelsSep 01, 2009Status-2 vote up vote down
Computerized Shutter Control of Canon DSLRsPhoto Status0 vote up vote down
Binary clock using LED matrix to display a binary clock with 6 digits of 4 binary bits eachTiming Status0 vote up vote down
Making an LM35 temperature recorder (based on PIC12F675) - logs to EEPROMData Acquisition Status0 vote up vote down
Schematics and C code for a PIC frequency counter operating up to about 50 MHz (7 segment)Test Status-1 vote up vote down
Universal Serial Infrared ReceiverIR Status-1 vote up vote down
Schematics and C code for a 0-5V PIC LCD volt meterTest Status0 vote up vote down
Driving led display matrix from a PIC microLED Status-2 vote up vote down
Schematics and C code for a PIC frequency counter operating up to about 50 MHz (LCD)Test Status-1 vote up vote down
PIC sonar (ultrasonic) range finding project with seven segment display using PIC microMicrocontroller Status0 vote up vote down
A Real Time Clock IC (DS1307) project using the PIC microMicrocontroller Status-2 vote up vote down
PIC Serial LCD project - An RS232 serial LCD interface using a standard HD44780 LCDMicrocontroller Status-1 vote up vote down
Stepper motor driver using PIC12F675 that offers serial port command interfaceControl Status0 vote up vote down
Stepper motor driver using PIC12F675Control Status-1 vote up vote down
Making an LM35 temperature recorder (based on PIC12F675) - serial outputData Acquisition Status-1 vote up vote down
Infrared remote control with intervalometer function for Nikon camerasPhoto Status1 vote up vote down
IR Remote Control for Nikon cameras, standard versionPhoto Status0 vote up vote down
Not So Tiny Power Meter - Measures power consumption for entire apartment Not So Tiny Power MeterTestFeb 21, 2013Status-1 vote up vote down
Accelerometer with microcontroller and displayData Acquisition Status-1 vote up vote down
Using a 555 Timer as an A/D converterData Acquisition Status0 vote up vote down
Serial cable for Casio QV-200 digital cameraPhoto Status0 vote up vote down
Locomotive signal braking moduleModels Status1 vote up vote down
H-Bridge Motor Control with Power MOSFETSControlMar 23, 2015Status-1 vote up vote down
Connect a Serial LCD Display to Raspberry PiMicrocontrollerMar 23, 2015Status-2 vote up vote down
DSP-RDF Doppler Radio Direction Finder circuit schematic - complete kit availableRFApr 14, 2011Status0 vote up vote down
White LED Drive CircuitLED Status-1 vote up vote down
Solar Powered Garden Light with PCB layoutSolarFeb 25, 2011Status0 vote up vote down
Low Power PLL FM Transmitter based on LMX1601 and Atmel ATtiny2313 or AT90S2313 microcontrollerTransmitters Status1 vote up vote down
Simplest LED Flasher Circuit using a 2N2222 transistor Simplest LED Flasher Circuit ledLED Status-1 vote up vote down
White LED StroboscopeLEDFeb 25, 2011Status1 vote up vote down
4th Order Butterworth filter schematic and calculatorFilterJan 16, 2010Status-1 vote up vote down
Wave Multiplier for music synthesizersMusicApr 27, 2003Status1 vote up vote down
Infinite melody for music synthesizersMusic Status0 vote up vote down
Nikon Coolpix 950 / 990 / 995 Flash-adapterPhotoSep 25, 2009Status0 vote up vote down
Digital clock that receives and displays the time from the Rugby MSF radio transmission (PIC16F877)Timing Status-2 vote up vote down
Remote shutter (or 'cable release') for SLR and DSLR camerasPhoto Status0 vote up vote down
Transistor based single zone intruder alarmAlarms Status-1 vote up vote down
CMOS single zone intruder alarmAlarms Status-1 vote up vote down
Automatic Intruder Alarm - a simple single-zone burglar alarm circuit based on a 4011 quad NAND gateAlarms Status-1 vote up vote down
Hijack alarmAutomotive Status-2 vote up vote down
Two-component metal detector using a 4093Metal Status6 vote up vote down
Simple temperature regulated FAN speed controllerControl Status-1 vote up vote down
RS-232 to TTL TranslatorMicrocontroller Status-1 vote up vote down
Car acceleration meterAutomotive Status-3 vote up vote down
Serial port I/O interface using AVR microcontrollerMicrocontroller Status0 vote up vote down
150W audio amplifier that's cheap to build using TIP142 / TIP147 Darlington power transistorsAmplifiers Status-5 vote up vote down
Infrared motion detector circuitIRNov 13, 2010Status0 vote up vote down
LED based transistor tester LED based transistor testerTestOct 05, 2012Status-1 vote up vote down
A Scenix (and PIC) ProgrammerProgrammersJan 26, 2001Status0 vote up vote down
Induced voltage sensor delta-peak trigger for coilgunMisc Status0 vote up vote down
Open loop pulse trigger module for coilgunMisc Status-1 vote up vote down
Optical speed trap to measure the the velocity of the projectileMisc Status0 vote up vote down
Optical trigger module for coilgunMisc Status-1 vote up vote down
Power MOSFET module for coilgunMisc Status0 vote up vote down
Three stage induced voltage triggered coilgunMisc Status0 vote up vote down
Thyristor fired coilgun circuit diagramMisc Status-1 vote up vote down
KITT (from Knight Rider) Car scanner using incandescant lampsAutomotive Status-1 vote up vote down
Magnetic levitation project from Electronics Now, February 1996Misc Status0 vote up vote down
LNS Technologies Levitator Kit circuit diagramMisc Status0 vote up vote down
Magnetic levitation project from Popular Electronics, May 1966Misc Status0 vote up vote down
Magnetic levitation project from Popular Electronics, May 1989Misc Status0 vote up vote down
Barry's magnetic levitation projectMisc Status0 vote up vote down
Barry's Coilgun Mark I circuit diagramsMisc Status0 vote up vote down
Barry's Coilgun Mark II circuit diagransMisc Status0 vote up vote down
Barry's Coilgun Mark III circuit diagransMisc Status0 vote up vote down
Barry's Coilgun Mark IV circuit diagransMisc Status0 vote up vote down
Circuit diagram for Coilgun Pistol Pskov 1100Misc Status-1 vote up vote down
MMC to PIC16F876 circuit diagramMicrocontrollerJun 18, 2003Status-1 vote up vote down
Circuits for interfacing microcontrollers to a wide number of real-word interfacesMicrocontroller Status-1 vote up vote down
50O Load and Power MeterRFFeb 21, 2013Status-1 vote up vote down
Simple Audio Tone Control CircuitAudioFeb 21, 2013Status0 vote up vote down
TTL pulse counter/logic probeTest Status-3 vote up vote down
General purpose ISA interface card for PCPC Status-1 vote up vote down
PC ISA Card Random Number GeneratorPC Status-1 vote up vote down
Hardware Random Number Generator with an SX microcontrollerMicrocontroller Status-1 vote up vote down
MIDI cable for Sound Blaster cardsPC Status-1 vote up vote down
PC ISA board containing a Z80 microprocessor (coprocessor card)PC Status-1 vote up vote down
8088 maximum mode SBCMicrocontrollerNov 16, 2002Status-1 vote up vote down
External antenna for the GPS-38, Magellan 2000, or Eagle Explorer GPS receiversRFMay 01, 2004Status0 vote up vote down
EZ80 single board computer schematic (Z80)MicrocontrollerApr 27, 2003Status-1 vote up vote down
8051 Development System Circuit Board circuit diagramMicrocontrollerJun 20, 2004Status-1 vote up vote down
Inexpensive infrared reflectometerIR Status1 vote up vote down
Sallen-Key Low Pass Filter Calculator (handles Butterworth filters, Bessel filters and Chebychev)FilterJan 16, 2010Status0 vote up vote down
Multi-User Jeopardy Game (Fastest Finger First)GamesOct 06, 2006Status1 vote up vote down
Commodore RF modulatorVideoJan 01, 2003Status0 vote up vote down
Shadow activated (or hand wave) motion detectorControl Status-1 vote up vote down
Constant current LED driver circuit using LM334 plus a transistorLEDJul 11, 2012Status0 vote up vote down
Laser light output intensity meterLaserOct 06, 2006Status0 vote up vote down
175KHz inductive pulse transmitter (PDF)TransmittersJan 26, 2001Status0 vote up vote down
175KHz inductive pulse receiver (PDF)RFJan 26, 2001Status2 vote up vote down
1-line telephone status indicator powered from a 3V battery (PDF)TelephoneJan 26, 2001Status0 vote up vote down
1uS light pulse descriminator plus F to V converter (PDF)MiscJan 26, 2001Status0 vote up vote down
1.5V LED flasher B (PDF)LEDJan 26, 2001Status1 vote up vote down
200-400 MHz voltage controlled oscillator (PDF)RFJan 26, 2001Status-1 vote up vote down
20MHz VCSEL 3mW laser test circuit (PDF)LaserJan 26, 2001Status0 vote up vote down
20MHz laser light detector (PDF)LaserJan 26, 2001Status2 vote up vote down
Broadband 2MHz optical fiber receiver (PDF)MiscJan 26, 2001Status0 vote up vote down
Line in use indicator that handles two independent phone lines (PDF)TelephoneJan 26, 2001Status0 vote up vote down
3KHz low-pass filter plus audio amp (PDF)FilterJan 26, 2001Status2 vote up vote down
Low current LED flasher (PDF)LEDJan 26, 2001Status0 vote up vote down
Pushbutton one-shot and latch (PDF)ControlJan 26, 2001Status-1 vote up vote down
Modulated light receiver circuit (PDF)MiscJan 26, 2001Status1 vote up vote down
Micro-power 40KHz burst laser diode driver (PDF)LaserJan 26, 2001Status0 vote up vote down
40KHz light receiver (PDF)IRJan 26, 2001Status0 vote up vote down
40KHz laser burst detector (PDF)LaserJan 26, 2001Status0 vote up vote down
40KHz TV-VCR repeater (PDF)IRJan 26, 2001Status0 vote up vote down
4-line telephone status indicator that is polarity independent (PDF)TelephoneJan 26, 2001Status0 vote up vote down
1uS light pulse receiver plus post amp (MISC)MiscJan 26, 2001Status0 vote up vote down
Broadband 5MHz optical fiber receiver (PDF)MiscJan 26, 2001Status0 vote up vote down
5W Fluorescent light intensity modulator (PDF)LightingJan 26, 2001Status0 vote up vote down
Line powered 60Hz clock generator (PDF)TimingJan 26, 2001Status0 vote up vote down
High-speed 75MHz light receiver (PDF)MiscJan 26, 2001Status0 vote up vote down
Micro-power pulse generator (PDF)TimingJan 26, 2001Status0 vote up vote down
1.5V LED flasher A (PDF)LEDJan 26, 2001Status1 vote up vote down
Flashing LED advertising badge (PDF)LEDJan 26, 2001Status0 vote up vote down
Flashing LED advertising badge (PDF)LEDNov 17, 2002Status0 vote up vote down
Honey Bee counter (PDF)Data AcquisitionJan 26, 2001Status-1 vote up vote down
Power reminder beeper (PDF)PowerJan 26, 2001Status-1 vote up vote down
Very loud beeper (PDF)AudioJan 26, 2001Status-1 vote up vote down
Darkroom camera shutter timerPhotoJan 26, 2001Status0 vote up vote down
Capacitance type liquid level measurement (PDF)Data AcquisitionJan 26, 2001Status0 vote up vote down
Unplugged power cord alarmPowerJan 26, 2001Status-1 vote up vote down
Modulated laser diode tester (PDF)LaserJan 26, 2001Status1 vote up vote down
Divide by 1.5 counter (PDF)TimingJan 26, 2001Status1 vote up vote down
Door knob alarm (PDF)AlarmsJan 26, 2001Status-1 vote up vote down
Basement doorbell beeper (PDF)MiscJan 26, 2001Status0 vote up vote down
Time to dust indicator - battery powered dust indicator (PDF)MiscJan 26, 2001Status-1 vote up vote down
Charge coupled bi-directional power MOSFET relay (PDF)ControlJan 26, 2001Status-1 vote up vote down
Finger touch activated switch (PDF)ControlJan 26, 2001Status1 vote up vote down
High-output square wave generator (PDF)TimingJan 26, 2001Status0 vote up vote down
1W Fluorescent lamp night light (PDF)LightingJan 26, 2001Status0 vote up vote down
Water seepage alarm (PDF)AlarmsJan 26, 2001Status-1 vote up vote down
Machine vibration triggers hour meter (PDF)ControlJan 26, 2001Status-1 vote up vote down
LASER/LED light output intensity meter (PDF)LaserJan 26, 2001Status0 vote up vote down
Solid state relay (PDF)ControlJan 26, 2001Status-1 vote up vote down
Digital noise generator (PDF)AudioJan 26, 2001Status-1 vote up vote down
D Flip-flot one-shot circuits (PDF)TimingJan 26, 2001Status1 vote up vote down
Low-power optical interrupter (PDF)MiscJan 26, 2001Status0 vote up vote down
Micro-power over temperature alarm (PDF)AlarmsJan 26, 2001Status-2 vote up vote down
Machine power loss beepter (PDF)PowerJan 26, 2001Status-1 vote up vote down
Simple nitrogen spark generator (PDF)MiscJan 26, 2001Status0 vote up vote down
Pulsed LED test circuit (PDF)LEDJan 26, 2001Status1 vote up vote down
Low battery voltage flasher (PDF)LEDJan 26, 2001Status2 vote up vote down
Video signal edge enhancementVideoJan 26, 2001Status1 vote up vote down
Long-period watchdog timerMicrocontrollerJan 26, 2001Status0 vote up vote down
Line-powered Xenon flash transmitter (PDF)ControlJan 26, 2001Status0 vote up vote down
9V Xenon photoflash controller (PDF)ControlJan 26, 2001Status-1 vote up vote down
Series Notch Fliter Designer / Calculator (displays circuit diagram after calculation)FilterJan 16, 2010Status0 vote up vote down
Cellular Phone calling DetectorTelephone Status0 vote up vote down
7MHz QRP transmitterTransmittersJul 09, 2002Status0 vote up vote down
Tone display systemAudioOct 30, 2002Status-1 vote up vote down
Tube amplifierTubeAug 14, 2002Status-2 vote up vote down
Analog Filters for Data Conversion (ADC filter)FilterJan 16, 2010Status0 vote up vote down
Simple DIY BFO metal detectorMetalJun 27, 2010Status4 vote up vote down
Transducer AmplifiersData Acquisition Status0 vote up vote down
Equivalent circuit and SPICE model of 555 timerTimingApr 11, 2011Status0 vote up vote down
ADC Input Driver DIFFERENTIAL to DIFFERENTIALData AcquisitionApr 11, 2011Status0 vote up vote down
ADC Input Driver DIFFERENTIAL to SINGLE-ENDEDData AcquisitionApr 11, 2011Status2 vote up vote down
ADC Input Driver FULLY DIFFERENTIAL AMPLIFIERData AcquisitionApr 11, 2011Status0 vote up vote down
ADC Input Driver SINGLE-ENDED to DIFFERENTIALData AcquisitionApr 11, 2011Status-1 vote up vote down
ADC Input Driver SINGLE-ENDED to SINGLE-ENDEDData AcquisitionApr 11, 2011Status1 vote up vote down
Op-Amp Current Source with Floating Load including SPICE simulationPowerMar 26, 2011Status-1 vote up vote down
H-Bridge Power Amp circuit diagram and SPICE simulation filesAmplifiersJan 17, 2011Status-6 vote up vote down
Op Amp Comparator with Hysteresis with SPICE simulationMiscMar 26, 2011Status1 vote up vote down
Op Amp Precision Half-wave Rectifier including SPICE simulationMiscMar 26, 2011Status0 vote up vote down
Op Amp based PID Controller circuit with SPICE simulationControlMar 26, 2011Status-2 vote up vote down
Op Amp Triangle-Wave Generator circuit diagram and SPICE simulation filesTimingJan 17, 2011Status0 vote up vote down
RC Low-Pass Filter with Op Amp Buffer (single pole filter) with SPICE simulation filesFilterJan 17, 2011Status0 vote up vote down
Single-Supply AC Inverting Op Amp amplifier with SPICE simulationMiscMar 26, 2011Status0 vote up vote down
Sallen-Key Low-Pass Filter (Double-Pole) with SPICE simulation filesFilterJan 17, 2011Status0 vote up vote down
Wien Bridge Oscillator with SPICE simulationTimingMar 26, 2011Status-1 vote up vote down
Basic Audio Amplifier including a SPICE modelAmplifiersApr 11, 2011Status0 vote up vote down
Thermostat node schematicData AcquisitionOct 31, 2002Status0 vote up vote down
No-Hum Fan ControllerControlSep 13, 2006Status-1 vote up vote down
PIC Web Server SchematicMicrocontrollerSep 13, 2006Status-1 vote up vote down
Micro based PIR to IR remote converterIROct 23, 2002Status0 vote up vote down
DIY Microphone Cable for iPod Touch (2nd Gen)PDASep 25, 2009Status0 vote up vote down
Hacking the Hot Wheels Radar Gun - includes circuit of analog front endMisc Status0 vote up vote down
Laser range finder and reflectivity meter for the MARS-96 international space project (PDF)LaserOct 06, 2006Status1 vote up vote down
12 Volt DC Fluorescent Lamp DriverLightingNov 13, 2010Status0 vote up vote down
Battery juicer provides a night light from almost flat batteries that would otherwise be dischardedLightingNov 13, 2010Status0 vote up vote down
Beam-break Detector For Camera Shutter or Flash ControlPhotoNov 13, 2010Status2 vote up vote down
Dual Polarity Unregulated PSU For High-End Audio AmpsPowerNov 13, 2010Status-1 vote up vote down
High Voltage Converter: 90V From 1.5VPowerNov 13, 2010Status-1 vote up vote down
Infra-red Light Barrier Using 555IRNov 13, 2010Status1 vote up vote down
Infra-Red Sensor/MonitorIRNov 13, 2010Status0 vote up vote down
IR On/Off Switch Using a PIC12F629 MicrocontrollerMicrocontrollerNov 13, 2010Status-2 vote up vote down
Infrared S/PDIF ReceiverIRNov 13, 2010Status-1 vote up vote down
RC5 Repeater to extend distance of infrared remote controlsIRNov 13, 2010Status-2 vote up vote down
Super Simple 3 Watt Audio Power Amplifier based on TDA1015AmplifiersNov 13, 2010Status-1 vote up vote down
Transistor TesterTestNov 13, 2010Status0 vote up vote down
VGA to BNC Adapter (Converter)VideoNov 13, 2010Status1 vote up vote down
White LED LampLEDNov 13, 2010Status-1 vote up vote down
Wire Tracer (Receiver)TestNov 13, 2010Status0 vote up vote down
Wire Tracer (Transmitter)TestNov 13, 2010Status0 vote up vote down
PIC ICDMicrocontrollerOct 23, 2002Status-2 vote up vote down
Dreamcast interfaceGamesAug 09, 2002Status-4 vote up vote down
Ultrasonic Range Finder & ImagerData AcquisitionJun 09, 2002Status1 vote up vote down
iPod / USB MP3 charger using MC34063 switchmode regulatorPDA Status0 vote up vote down
Elecraft XG2 receiver test oscillator (PDF)TestSep 13, 2006Status-1 vote up vote down
Infrared beam barrier / proximity detectorIR Status-1 vote up vote down
Simple electronic buzzerAudio Status-1 vote up vote down
Big Ben sound effects generatorAudio Status-1 vote up vote down
Charge Monitor for 12V lead acid batteryPower Status0 vote up vote down
Wiper Speed ControlAutomotive Status1 vote up vote down
PC based Frequency MeterPC Status-1 vote up vote down
7 segment rolling display using PCPC Status-1 vote up vote down
JAM(Just A Minute) Quiz Game CircuitGames Status1 vote up vote down
Running Message DisplayLED Status0 vote up vote down
Simple car battery chargerAutomotiveJun 18, 2003Status-1 vote up vote down
Clap activated remote controlControl Status-1 vote up vote down
Contactless Mains Voltage IndicatorTest Status-1 vote up vote down
Automatic Staircase Light 1Lighting Status0 vote up vote down
Automatic Staircase Light 2Lighting Status0 vote up vote down
Clack Clack Electronic BellAudio Status0 vote up vote down
Electronic Astrologer (decision maker)Games Status0 vote up vote down
Electronic diceGames Status0 vote up vote down
Light Operated SwitchControl Status-1 vote up vote down
Mini emergency lightLighting Status-1 vote up vote down
Mini tester: Handles continuity testing, resistor testing, capacitor testing and diode testingTest Status1 vote up vote down
Musical Electronic BellAudio Status-1 vote up vote down
MW Transmitter can be used as an inter-room radio telephoneTransmitters Status0 vote up vote down
NiCd Cell ChargerPower Status-2 vote up vote down
Pocket Transmitter that can cover 20 to 25 meters with a telescopic antennaTransmitters Status1 vote up vote down
Reflex Action GameGames Status1 vote up vote down
Simple Traffic Light ControllerModels Status0 vote up vote down
Voice AmplifierAmplifiers Status-4 vote up vote down
Discrete LED Color OrganLED Status0 vote up vote down
Automatic Plant Irrigation System Circuit for Watering Plants without any Human Interference.MiscDec 07, 2014Status-1 vote up vote down
BCD to 7 Segment LED Display Decoder CircuitLEDApr 26, 2014Status1 vote up vote down
25W MOSFET audio amplifierAmplifiersFeb 21, 2005Status2 vote up vote down
50W audio amplifier using ICL8063AmplifiersFeb 21, 2005Status-4 vote up vote down
Digital volume controlAudioFeb 21, 2005Status-2 vote up vote down
Electronic attenuatorAudioFeb 21, 2005Status1 vote up vote down
Speech recorded using ISD2560AudioFeb 21, 2005Status-1 vote up vote down
Precision audio millivoltmeterTestFeb 21, 2005Status-5 vote up vote down
Amplified ear for surveillanceAmplifiersFeb 21, 2005Status-2 vote up vote down
Flashing / pulsing third brake like for carsAutomotiveFeb 21, 2005Status-2 vote up vote down
Headlight flasherAutomotiveFeb 21, 2005Status-3 vote up vote down
Speed alert - wireless portable unitAutomotiveFeb 21, 2005Status0 vote up vote down
Parking aid senses distance to rear of vehicleAutomotiveFeb 21, 2005Status-1 vote up vote down
Automatic headlight brightness switchAutomotiveFeb 21, 2005Status-1 vote up vote down
Flashing heartGamesFeb 21, 2005Status-1 vote up vote down
Electronic millipede robotModelsFeb 21, 2005Status0 vote up vote down
Circuit diagram of 3V LED chaser using 4017LEDFeb 21, 2005Status0 vote up vote down
6V ultra-bright LED chaser using 74HC4017LEDFeb 21, 2005Status0 vote up vote down
Smart card programmerProgrammersFeb 21, 2005Status0 vote up vote down
Decoder for encoded transmissions in Videocrypt and D2MACVideoFeb 21, 2005Status0 vote up vote down
Circuit for gold wafer cardMiscFeb 21, 2005Status1 vote up vote down
Jupiter card programemrProgrammersFeb 21, 2005Status-1 vote up vote down
PIC16F84 based diode testerTestFeb 21, 2005Status-2 vote up vote down
Nokia 3310 Lcd Thermometer using DS18B20MiscFeb 21, 2005Status0 vote up vote down
Lost keys finder using HCF4069MiscFeb 21, 2005Status1 vote up vote down
SmartCard PC EmulatorPCFeb 21, 2005Status-1 vote up vote down
Economy radar detectorAutomotiveFeb 21, 2005Status-2 vote up vote down
S-Video to RCA adapterVideoFeb 21, 2005Status0 vote up vote down
Digital pedometer circuit diagramMedicalFeb 21, 2005Status-1 vote up vote down
Cellular Phone calling detector (detects RF field)TelephoneFeb 21, 2005Status0 vote up vote down
Cuckoo sound generatorAudioFeb 21, 2005Status-1 vote up vote down
RS-232 Laser TransceiverLaserMay 01, 2004Status-1 vote up vote down
RS-232 laser transceiverLaserFeb 21, 2005Status-1 vote up vote down
Casio dataloggerPDAFeb 21, 2005Status1 vote up vote down
Relay interface add-on board for PCPCFeb 21, 2005Status-1 vote up vote down
8-way relay interface board for PC parallel printer portPCFeb 21, 2005Status-1 vote up vote down
Stepper motor controller for PC parallel portPCFeb 21, 2005Status-2 vote up vote down
3-axis stepper motor controller for PC parallel portPCFeb 21, 2005Status-2 vote up vote down
Optically isolated stepper motor controllerControlFeb 21, 2005Status-1 vote up vote down
PC based thermometer based on Dallas DS1621PCFeb 21, 2005Status-1 vote up vote down
VGA to SCART adapterVideoFeb 21, 2005Status-4 vote up vote down
Basic UPS Power SupplyPowerFeb 21, 2005Status0 vote up vote down
Fuse monitor / alarmPowerFeb 21, 2005Status-1 vote up vote down
4 watt FM transmitter circuit diagramTransmittersFeb 21, 2005Status0 vote up vote down
FM transmitter bugTransmittersFeb 21, 2005Status0 vote up vote down
Television signal amplifierVideoFeb 21, 2005Status-1 vote up vote down
Small radio transmitterTransmittersFeb 21, 2005Status0 vote up vote down
Electronic Eavesdropping Devices Detector (bug detector)RFFeb 21, 2005Status-2 vote up vote down
20dB VHF AmplifierRF_AmplifierFeb 21, 2005Status4 vote up vote down
30 watt FM linear amplifier circuit diagramRF_AmplifierFeb 21, 2005Status-2 vote up vote down
AM transmitterTransmittersFeb 21, 2005Status0 vote up vote down
2 Transistor FM Voice TransmitterTransmittersFeb 21, 2005Status-1 vote up vote down
Linear FM 50 watt amplifier with BLY90RF_AmplifierFeb 21, 2005Status0 vote up vote down
15 watt FM transmitter circuit schematicTransmittersFeb 21, 2005Status-1 vote up vote down
Video signal amplifier circuitVideoFeb 21, 2005Status0 vote up vote down
CB (27MHz citizens band) receiverRFFeb 21, 2005Status-2 vote up vote down
Circuit for three axis robot arm based on stepper motors out of 5 1/4" drivesModelsNov 10, 2009Status-1 vote up vote down
Lightning DetectorMiscFeb 21, 2005Status-2 vote up vote down
Geomagnetic field detectorMiscFeb 21, 2005Status-1 vote up vote down
Frost alarmAlarmsFeb 21, 2005Status-1 vote up vote down
Ultrasonic radar alarmAlarmsFeb 21, 2005Status-1 vote up vote down
iRDA transceiver to extend IR port range up to 15 metersIRFeb 21, 2005Status0 vote up vote down
Remote digital thermometer sends data over AC power lineData AcquisitionFeb 21, 2005Status0 vote up vote down
Telephone music on hold interfaceTelephoneFeb 21, 2005Status0 vote up vote down
Soft musical telephone ringerTelephoneFeb 21, 2005Status0 vote up vote down
Telephone amplifierTelephoneFeb 21, 2005Status1 vote up vote down
Telephone line monitorTelephoneFeb 21, 2005Status0 vote up vote down
Cut telephone line detectorTelephoneFeb 21, 2005Status0 vote up vote down
FM telephone line bug transmitter (88MHz to 94MHz)TelephoneFeb 21, 2005Status0 vote up vote down
Continuity tester using transistorsTestFeb 21, 2005Status-2 vote up vote down
Latching continuity tester using 4093TestFeb 21, 2005Status-1 vote up vote down
IR remote control testerIRFeb 21, 2005Status0 vote up vote down
Linear Resistance MeterTestFeb 21, 2005Status-2 vote up vote down
Crystal tester circuit diagramTestFeb 21, 2005Status0 vote up vote down
Capacitance meterTestFeb 21, 2005Status1 vote up vote down
Digital voltmeter (DVM)TestFeb 21, 2005Status-1 vote up vote down
Transistor tester using 555 timer and 4027TestFeb 21, 2005Status-3 vote up vote down
Function generator based upon 8038 waveform generator ICTestFeb 21, 2005Status0 vote up vote down
Triangle / Square wave generatorTimingFeb 21, 2005Status0 vote up vote down
Picoammeter circuit schematic with 4 ranges using CA3420TestFeb 21, 2005Status-2 vote up vote down
Beeper to find short circuits (continuity tester)TestFeb 21, 2005Status1 vote up vote down
Voltage follower with 1G ohm input resistanceData AcquisitionFeb 21, 2005Status0 vote up vote down
Led display digital VoltmeterLEDFeb 21, 2005Status0 vote up vote down
MOSFET tester for N-type MOSFET transistorsTestFeb 21, 2005Status-1 vote up vote down
Inductive meter adapter to measure inductance using a frequency counterTestFeb 21, 2005Status-1 vote up vote down
Crystal tester that covers a range of 32kHz to 24MHzTestFeb 21, 2005Status-1 vote up vote down
Oscilloscope testing module (Huntron circuit) that shows Lissajous patternsTestFeb 21, 2005Status-1 vote up vote down
Voltage monitor with LED indicatorPowerFeb 21, 2005Status-2 vote up vote down
Logic probe with 7-segment display based on 74LS00 and 74LS47TestFeb 21, 2005Status-1 vote up vote down
Wireless transmitter for PIR using Holtek HT12ETransmitters Status0 vote up vote down
OPT301 Laser receiverLaser Status1 vote up vote down
Heartbeat transducer using infrared LED / detectorMedical Status0 vote up vote down
ECG amplifier with right leg driveMedical Status1 vote up vote down
High current regulated power supplyPowerOct 31, 2002Status-1 vote up vote down
Low-voltage light dimmerLightingNov 17, 2002Status-1 vote up vote down
Active bandpass filtersFilterNov 01, 2002Status1 vote up vote down
Bandpass filtersFilterNov 01, 2002Status-1 vote up vote down
AM BCB radio receiverRFOct 23, 2002Status0 vote up vote down
Regenerative shortwave receiverRFJun 08, 2002Status-1 vote up vote down
Miniature audio amplifierAmplifiers Status-2 vote up vote down
Optical Heart Rate MonitorMedicalSep 10, 2006Status-2 vote up vote down
PIC Project #1 - RS232 to I2C InterfaceMicrocontrollerJan 26, 2001Status-1 vote up vote down
RF front-end for triple conversion GPS receiver (PDF)RFMar 01, 2003Status1 vote up vote down
Design and build your own iPod docking stationPDAMay 30, 2007Status0 vote up vote down
Various tube crossover circuitsTubeJan 31, 2003Status0 vote up vote down
Serial Port A/D-converterData AcquisitionJan 26, 2001Status-1 vote up vote down
Audio amplifier output relay delayAmplifiersJan 26, 2001Status-2 vote up vote down
TV/Radio antenna cable galvanic isolatorVideoJan 26, 2001Status0 vote up vote down
Audio line isolatorAudioJan 26, 2001Status-2 vote up vote down
Connect two CD-ROM drives to one soundcardPCJan 26, 2001Status-1 vote up vote down
Centronics port D/A converters and low-pass filterData AcquisitionJan 26, 2001Status0 vote up vote down
4-channel dimmer rack circuit diagramLightingNov 17, 2002Status2 vote up vote down
Dynamic microphone to electret microphone inputAudioJan 26, 2001Status-1 vote up vote down
Fogger smoke machine controllerMiscJan 26, 2001Status0 vote up vote down
Headphone driving circuit for soundcardsPCJan 26, 2001Status-1 vote up vote down
Simple line mixerMusicJan 26, 2001Status0 vote up vote down
Simple IR transmitter circuitIRJan 26, 2001Status0 vote up vote down
Simple infra-red detectorIRJan 26, 2001Status1 vote up vote down
Experimental laser data linkLaserJan 26, 2001Status0 vote up vote down
Simple light sensor adapter for oscilloscopeTestJan 26, 2001Status-1 vote up vote down
Line level signal to microphone input adapterAudioJan 26, 2001Status-2 vote up vote down
Simple two line output combinerAudioJan 26, 2001Status-1 vote up vote down
Adjustable power supply using LM317PowerJan 26, 2001Status-2 vote up vote down
Get power out of PC parallel portPCJan 26, 2001Status-1 vote up vote down
Simple microphone preamplifierPreampJan 26, 2001Status1 vote up vote down
Electret microphone powering circuitsAudioJan 26, 2001Status-2 vote up vote down
Simple MIDI testerMusicJan 26, 2001Status0 vote up vote down
Null Printer AdapterPCJan 26, 2001Status-1 vote up vote down
PC speaker volume control circuitPCJan 26, 2001Status-1 vote up vote down
Use amplifier phono input as line level inputAmplifiersJan 26, 2001Status-2 vote up vote down
How to get power from PC to your circuitsPCJan 26, 2001Status-1 vote up vote down
Simple +5V power supply circuitPowerJan 26, 2001Status-1 vote up vote down
RS-232 surge protectionPCJan 26, 2001Status-1 vote up vote down
Simple RS-232 serial port buffer circuitPCJan 26, 2001Status-1 vote up vote down
Get power out of PC RS-232 portPCJan 26, 2001Status-1 vote up vote down
Sound Blaster Microphone PreamplifierPCJan 26, 2001Status-2 vote up vote down
Sega 3D glasses interface circuit diagramsPCJan 26, 2001Status-1 vote up vote down
0-10V control for RC servosModelsJan 26, 2001Status0 vote up vote down
Speaker signals to line level inputsAudioJan 26, 2001Status-1 vote up vote down
S-video to composite video adapterVideoJan 26, 2001Status1 vote up vote down
TDR cable reflection tester (Time Domain Reflectometer)TestSep 21, 2006Status0 vote up vote down
Telephone privacy adapterTelephoneJan 26, 2001Status1 vote up vote down
Telephone ringing circuitsTelephoneJan 26, 2001Status0 vote up vote down
Simple circuit to connect telephone equipment to audio mixerTelephoneJan 26, 2001Status1 vote up vote down
VGA to RGB + composite sync -converterVideo Status-2 vote up vote down
VGA to TV converterVideoJan 26, 2001Status-3 vote up vote down
VGA to PAL and NTSC converterVideoJan 26, 2001Status0 vote up vote down
A-weighting filter from an old Ampex service manualFilterMay 07, 2010Status0 vote up vote down
Convert Atari-style joystick to PC joystick portPCJan 26, 2001Status-1 vote up vote down
Fake Joystick circuitPCJan 26, 2001Status-1 vote up vote down
Using the joystick port as general purpose inputPCJan 26, 2001Status-1 vote up vote down
Connect other circuits to PC joystick portPCJan 26, 2001Status-1 vote up vote down
HeNe laser power supplyLaserJun 09, 2002Status-2 vote up vote down
Video/Audio Wireless TransmitterVideoOct 23, 2002Status-2 vote up vote down
Using an ADXL330 accelerometer with an AVR microcontrollerMicrocontrollerJan 09, 2010Status-1 vote up vote down
Peggy - A Light Emitting Pegboard DisplayLED Status-2 vote up vote down
LPG leakage alarm using SEN-1327 gas sensor module (detects 4 other dangerous gases)AlarmsJul 17, 2012Status-2 vote up vote down
Build your own iRDA SIR Transceiver (Dongle) using MCP2120PCAug 27, 2003Status-2 vote up vote down
Programmable Optical Slave Flash Trigger for Digital Cameras using PIC12F675Photo Status1 vote up vote down
7MHz SSB TransceiverRFMay 01, 2004Status-1 vote up vote down
Homebuilt MP3 PlayerMusic Status0 vote up vote down
5 Zone Alarm Circuit circuit diagramAlarms Status-1 vote up vote down
Strain gauge sensor interfaceData Acquisition Status0 vote up vote down
Ultrasonic Distance Measurer based on Freescale MC9RS08KA2 (PDF)Microcontroller Status-1 vote up vote down
Model 2030 XRAY monitor instruction manual including schematics (PDF)MedicalSep 13, 2006Status3 vote up vote down
Rangefinder with Fast Multiple Range CapabilityLaserOct 06, 2006Status0 vote up vote down
Laser diode transmitter RF sectionLaser Status1 vote up vote down
DC Fault Protection Circuit for Audio AmplifiersAmplifiersJan 29, 2010Status-3 vote up vote down
Soft Power On Tester for AmplifiersTestJan 29, 2010Status0 vote up vote down
Zonk Machine and Treble BoosterMusicJan 31, 2003Status2 vote up vote down
Pulse Induction Metal Detector part 1 (PDF)MetalJun 27, 2010Status2 vote up vote down
Pulse Induction Metal Detector part 2 (PDF)MetalJun 27, 2010Status-8 vote up vote down
Lightning shutter trigger for a camera using an ArduinoArduinoNov 13, 2010Status-1 vote up vote down
Camera Axe open hardware and open software project for camera triggeringPhotoNov 13, 2010Status0 vote up vote down
Direction sensing infrared motion detector using PIR (PDF)IR Status0 vote up vote down
Universal telephone holdTelephoneJan 26, 2001Status0 vote up vote down
Video switcher - run up to four cameras into one video monitor (PDF)Video Status0 vote up vote down
Talking phone dial monitor (PDF)TelephoneJan 26, 2001Status-1 vote up vote down
Stepper motor positionerControlJan 26, 2001Status-1 vote up vote down
Infrared Motion Detector using a PIR sensor (PDF)IR Status1 vote up vote down
Pyroelectric Infrared (PIR) SensorIRJan 26, 2001Status-1 vote up vote down
Mobile APRS / GPS tracking systemMiscMay 01, 2004Status0 vote up vote down
GPS receiver support kitMiscMay 01, 2004Status0 vote up vote down
GPS receiver (Gamin, Eagle etc) to PC interface cablesPCMar 23, 2003Status-1 vote up vote down
Heart of LEDsLEDOct 23, 2002Status1 vote up vote down
Christmas StarLEDOct 23, 2002Status-1 vote up vote down
Christmas treeLEDOct 23, 2002Status-1 vote up vote down
Simple Skype VoIP analog adapterTelephoneSep 10, 2006Status0 vote up vote down
Brain-Wave MachineMedicalNov 27, 2002Status2 vote up vote down
Cranial Electrotherapy Stimulation (CES) circuit diagramMedical Status-1 vote up vote down
Lie detectorMedicalOct 30, 2002Status4 vote up vote down
Simple lie detectorMedicalOct 30, 2002Status0 vote up vote down
Furby reverse-engineered circuitGamesApr 27, 2003Status0 vote up vote down
Circuit and Arduino sketch for interfacing to a DS18B20 1-wire temperature sensorArduinoJul 21, 2013Status-2 vote up vote down
TXTVb - 70cm ATV Test Generator (PDF)Test Status-1 vote up vote down
BCD readout frequency counterTestAug 18, 2009Status-1 vote up vote down
Binary clock circuit diagramTimingAug 18, 2009Status0 vote up vote down
Experimental DDS frequency synthesizer uses the AD9851TimingOct 08, 2009Status-1 vote up vote down
Dekatron circuit diagram - device used for dividing by 10 during the valve eraTubeOct 25, 2009Status0 vote up vote down
Circuit diagrams for making logic gates from discrete componentsMiscOct 25, 2009Status0 vote up vote down
Simple intercom circuit diagramTelephoneOct 25, 2009Status-1 vote up vote down
LCD Frequency CounterTestAug 18, 2009Status0 vote up vote down
Circuit for remote lighting controller using a 433MHz AM keyfob transmitterLightingOct 25, 2009Status0 vote up vote down
LED matrix clock circuit diagramTimingAug 18, 2009Status1 vote up vote down
Miniscope - simple all-valve 1-inch CRT oscilloscopeTubeOct 25, 2009Status1 vote up vote down
Positive Feedback Circuit for Isometric Muscle ExperimentsMedicalNov 05, 2009Status1 vote up vote down
Z80 Computer circuit diagramPCAug 18, 2009Status1 vote up vote down
Giant nixie clock circuit diagramTubeAug 18, 2009Status0 vote up vote down
Panel-mounting clock circuit diagramTimingAug 18, 2009Status0 vote up vote down
Basic 78xx series regulator mains power supply circuit diagramPowerOct 25, 2009Status-2 vote up vote down
Simple QRSS callsign keyer based on an Atmega AVR programmed in CProgrammersNov 05, 2009Status0 vote up vote down
Panel Mounting Radio Frequency CounterTestAug 18, 2009Status-1 vote up vote down
Giant T-shaped LED matrix display board for financial applications containing 275 8x8 LED modulesLEDOct 25, 2009Status-1 vote up vote down
Simple Frequency CounterTestAug 18, 2009Status-1 vote up vote down
Sidereal clock project with circuit diagramsTimingAug 18, 2009Status1 vote up vote down
Heathkit signal generator user manual and circuit diagramTestOct 25, 2009Status-1 vote up vote down
Spectrum analyzer Mk 1TestAug 18, 2009Status3 vote up vote down
Spectrum analyzer Mk 2TestAug 18, 2009Status1 vote up vote down
TinyScope - simple all-valve 1-inch CRT oscilloscopeTubeOct 25, 2009Status0 vote up vote down
Asynchronous 40-bit TTL CPUMicrocontrollerAug 18, 2009Status-1 vote up vote down
USB charger circuit diagramPowerAug 18, 2009Status0 vote up vote down
Z80 controlled Viscometer projectTestAug 18, 2009Status0 vote up vote down
Wind speed loggerData AcquisitionOct 25, 2009Status1 vote up vote down
Wind speed logger Mk2Data AcquisitionOct 25, 2009Status0 vote up vote down
The Great Z80 Computer ProjectPCAug 18, 2009Status0 vote up vote down
AVR-Based Serial Port IR ReceiverMicrocontrollerOct 23, 2002Status-1 vote up vote down
Ethernet interface for Commodore 64 computerPC Status-2 vote up vote down
i2c-tiny-usb, a simple i2c interface for the usb portPC Status-1 vote up vote down
LCD2USB, cheap open source text LCD interfacePC Status-1 vote up vote down
LEDMATRIX, a 80x32 pixel DIY LED matrix displayLED Status1 vote up vote down
Interfacing ADXL202 accelerometer to PalmPilotPDAApr 27, 2003Status-1 vote up vote down
SPI2CF, a fast and efficient WLAN interface for the AVRMicrocontroller Status-1 vote up vote down
TiltStick, a motion sensing device (USB interface to accelerometer)PC Status-1 vote up vote down
Minimum Theremin Kit SchematicAudioSep 13, 2006Status-1 vote up vote down
FM radio for a PIC (uses TDA7000 IC which is now obsolete)PCSep 08, 2009Status-1 vote up vote down
Lightning detector circuit diagramMiscSep 08, 2009Status0 vote up vote down
Build an iButton electronic lock based around a AT91C2051 microcontroller (includes ASM source code)AlarmsNov 10, 2009Status-1 vote up vote down
AM receiver circuit diagramRFSep 08, 2009Status0 vote up vote down
Using an Apple II+ Computer as a Flash Intervalometer (PDF)PhotoMay 09, 2010Status1 vote up vote down
Heathkit Groundtrack GR-1290 VLF metal detector circuit diagram and detector coil construction notesMetalJun 27, 2010Status-5 vote up vote down
White's Surfmaster PI (pulse induction) metal detector schematic diagramMetalJun 27, 2010Status5 vote up vote down
Ultrasonic Radar Alarm Circuit DiagramAlarms Status-1 vote up vote down
10 tricks for interfacing to the PIC16C508MicrocontrollerNov 05, 2009Status-1 vote up vote down
Circuit to connect a rotary encoder to a Arduino UNOArduinoJul 21, 2013Status-1 vote up vote down
555 Based Simple Servo ControllerControl Status1 vote up vote down
Fluorescent Tube "Strip light" DriverLighting Status0 vote up vote down
Field Strength Meter (FSM) covers 2Mhz - 1Ghz with peak reception at 3-200MhzTest Status0 vote up vote down
Simple Function Generator using TL084 or other opampTiming Status-2 vote up vote down
H Bridge controller for DC motorsControl Status0 vote up vote down
Advanced High Voltage PSU circuitPower Status-1 vote up vote down
Authentic Looking Knight Rider Led ProjectAutomotive Status-1 vote up vote down
6 Pole ElectroMagnet Motor (aka Simple Brushless motor)Misc Status-1 vote up vote down
88-108Mhz FM Radio Transmitter with 3 transistor stagesTransmitters Status1 vote up vote down
Serial servo controller for interfacing hobby servos via RS232 to a PCPC Status-1 vote up vote down
Solid State Tesla Coil and Wireless PowerMisc Status0 vote up vote down
Tesla coil construction projectMisc Status0 vote up vote down
12 Vdc - 120 Vac Inverter SchematicPowerJan 01, 2003Status-2 vote up vote down
POV Persistence Of Vision 2 x 32 LED displayLED Status1 vote up vote down
Vareity of circuits for interfacing to/from TTL logicMisc Status0 vote up vote down
Victoria TAFE programmer (based on AT89C2051)ProgrammersJan 31, 2003Status0 vote up vote down
JDM programmer circuit diagramProgrammersJan 31, 2003Status0 vote up vote down
PIC micro programmer circuit diagramProgrammersJan 31, 2003Status-1 vote up vote down
Dinsmore 1490 digital compassMiscNov 29, 2002Status0 vote up vote down
Geiger counter circuit diagramMiscNov 29, 2002Status-2 vote up vote down
Speech recognition using HM2007MicrocontrollerNov 29, 2002Status-1 vote up vote down
PIC microcontroller servo motor interfaceMicrocontrollerNov 29, 2002Status-1 vote up vote down
PIC micro multiple servo motor interfaceMicrocontrollerNov 29, 2002Status-1 vote up vote down
Electric field disturbance monitorMiscJan 26, 2001Status0 vote up vote down
3 KHz low pass filter plus audio amplifier circuit diagramFilterApr 14, 2010Status1 vote up vote down
Micropower pulse generator (PDF)TimingJan 26, 2001Status0 vote up vote down
Inexpensive seismometer projectMiscDec 15, 2002Status0 vote up vote down
Constant current LED driver circuit using an NPN transistor to control an N-channel MOSFETLEDJul 11, 2012Status0 vote up vote down
Simple 430MHz band FM transmitter uses only 2 FETtransistorsTransmitters Status0 vote up vote down
110mW emitter follower audio power amplifierAmplifiersJan 22, 2010Status-3 vote up vote down
AM transmitter using no power supplyTransmitters Status3 vote up vote down
NE555 drives a speakes: Pulse Width Modulation AmplifierAmplifiersMar 30, 2010Status-5 vote up vote down
UHF signal generatorTest Status0 vote up vote down
VHF signal generatorTest Status0 vote up vote down
Judge Dredd pinball locking ring modificationGames Status0 vote up vote down
PIC micro frame grabber (TDA8708)VideoFeb 01, 2003Status0 vote up vote down
Digitally Addressable DALI Dimming Ballast (PDF)LightingDec 27, 2004Status0 vote up vote down
New and Improved Sound Card Packet Interface tested with PSK31 and APRSPCOct 27, 2009Status-1 vote up vote down
Home security projectAlarmsNov 17, 2002Status-1 vote up vote down
PC Controlled RC car construction projectModels Status0 vote up vote down
Pulse Circuits for Infrared LEDs and Visible Diode LasersLaserAug 04, 2012Status-1 vote up vote down
Pulse Circuits for Infrared LEDs and Visible Diode LasersLaserMar 04, 2010Status2 vote up vote down
LED Modulation Circuits including 5MHz and 50MHz versionsLEDApr 17, 2011Status0 vote up vote down
Measuring the speed of light with an infrared LED / photodiode (TDOA)IRJun 13, 2011Status0 vote up vote down
Canon DSLR cable shutter release usin 4N25 for optical isolationPhotoSep 25, 2009Status0 vote up vote down
Spatial Distortion Reduction Headphone AmpAmplifiersJan 31, 2003Status-2 vote up vote down
Simple GPS Stabilised 10 MHz OscillatorTiming Status1 vote up vote down
Sanyo 20EZ monitor circuit diagramPCMar 18, 2003Status-1 vote up vote down
Burger Time Arcade Game circuit diagram (PDF)GamesMar 17, 2009Status-1 vote up vote down
Dig Dug Arcade Game (800k ZIP)GamesMar 18, 2003Status1 vote up vote down
Frogger Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status-1 vote up vote down
Frogger Sound/ROM - FROGSND Arcade game circuit diagram (PDF)GamesMar 30, 2014Status0 vote up vote down
Gyrus Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Junior Pacman Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status1 vote up vote down
Ladybug Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status1 vote up vote down
Mappy Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Moon Cresta Arcade circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Mr.Do Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Pengo Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
PacLand Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Q*Bert Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Qix Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status0 vote up vote down
Scramble Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status-2 vote up vote down
Time Pilot'84 Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status-1 vote up vote down
Xevious Arcade Game circuit diagram (PDF)GamesMar 18, 2003Status-1 vote up vote down
Robotic microcontroller boardModelsJan 31, 2003Status0 vote up vote down
Single to 3-phase power conversionPower Status-1 vote up vote down
Low noise PIN diode laser receiver circuitLaser Status0 vote up vote down
Circuits for biasing and modulating laser diodesLaser Status0 vote up vote down
inexpensive high speed microwave data link using an Alpha Gunnplexer for 10 Mbps data rateRF Status0 vote up vote down
18 dB LT1253 DDS amplifier circuit diagramRF_Amplifier Status0 vote up vote down
23 dB Bipolar DDS AmplifierRF_Amplifier Status0 vote up vote down
15M CW Transceiver designRF Status0 vote up vote down
20 Meter CW TransceiverRF Status2 vote up vote down
30 Meter, Discrete Component CW Transceiver Built Manhattan-styleRF Status0 vote up vote down
K8IQY's Original 2N2/40 CW Transceiver RigRF Status0 vote up vote down
40 to 6 Meter "No Tune" TransverterRF Status0 vote up vote down
SW30+ 30 Meter CW TransceiverRF Status0 vote up vote down
-20 dB Couplers for use with a with a spectrum analyzer or other sensitive detectorTest Status0 vote up vote down
-20 dBm, 14.060 MHz Precision Signal SourceTest Status0 vote up vote down
RC Audio OscillatorAudio Status-1 vote up vote down
Precision VXO for Crystal Characterization & MatchingTest Status0 vote up vote down
Return Loss BridgeTest Status-1 vote up vote down
Lossless portable digital audio player using the Microchip PIC32Music Status-1 vote up vote down
Water system controller (PDF)Control Status-1 vote up vote down
GPS LCD Display ProjectMicrocontrollerJul 24, 2002Status-1 vote up vote down
PIC16F84 LED chaserMicrocontrollerNov 17, 2002Status-1 vote up vote down
PIC micro LED projectsMicrocontrollerJun 18, 2003Status-1 vote up vote down
PS/2 keyboard keystroke logger based on Atmel 89C2051MicrocontrollerJun 20, 2004Status-1 vote up vote down
Breadboard supply - very low dropout adjustable power supplyPowerOct 12, 2009Status0 vote up vote down
Bedazzler: Do-it-yourself Handheld LED-Incapacitator (non-lethal weapon)LEDOct 12, 2009Status0 vote up vote down
Dimmable Li-Ion Halogen Bike LightLightingOct 12, 2009Status0 vote up vote down
Solderless Breadboard Arduino Clone for Arduino prototypingArduinoOct 12, 2009Status-1 vote up vote down
Digg Button KitMiscOct 12, 2009Status0 vote up vote down
Drawdio - A very simple musical synthesizer that uses the conductive properties of pencil graphiteMusicOct 12, 2009Status0 vote up vote down
Ethernet shield for Arduino (Xport)ArduinoOct 12, 2009Status-1 vote up vote down
Fuzebox - open source 8-bit game console based on Atmel ATmega644-20PUGamesOct 12, 2009Status0 vote up vote down
GPS / Datalogging shield for Arduino microcontrollerArduinoOct 12, 2009Status0 vote up vote down
Ice Tube Clock - Vacuum fluorescent display (VFD) clockTubeOct 12, 2009Status0 vote up vote down
Real-world MIDI interface platform project including circuit diagram and PCB design filesMusicOct 12, 2009Status0 vote up vote down
Persistance of vision (POV) toyGamesOct 12, 2009Status0 vote up vote down
Portable MP3 music playerMusicOct 12, 2009Status0 vote up vote down
Small battery-powered USB charger including circuit diagram and PCB layoutPowerOct 12, 2009Status0 vote up vote down
Arduino based controller interface for servo motors, stepper motors and DC motorsArduinoOct 12, 2009Status0 vote up vote down
Arduino microcontroller prototyping systemArduinoOct 12, 2009Status-1 vote up vote down
SIM card reader circuit diagramMiscOct 12, 2009Status0 vote up vote down
Persistence of Vision Display for BikesLEDOct 12, 2009Status0 vote up vote down
High power infrared remote control to turn off television sets from a distanceIROct 12, 2009Status0 vote up vote down
USBtinyISP - AVR programmer & SPI interface projectProgrammersOct 12, 2009Status0 vote up vote down
Wave Bubble self-tuning portable RF jammerRF Status0 vote up vote down
Wave Bubble - A design for a self-tuning portable RF jammerRFOct 12, 2009Status1 vote up vote down
Wave (Audio) shield for Arduino microcontrollerArduinoOct 12, 2009Status0 vote up vote down
Bassline synthesizer/sequencerMusicOct 12, 2009Status-3 vote up vote down
YBox2 - DIY networked set-top box that connects to a TV to deliver Internet contentVideoOct 12, 2009Status1 vote up vote down
Mini-Beacon - miniature programmable LED Flasher that is based around a PIC12F629 microcontrollerLED Status0 vote up vote down
Subwoofer Filter, Gainer, Auto Power SystemAudio Status-1 vote up vote down
PC-based ISA data acquisition and control boardPCSep 13, 2006Status-1 vote up vote down
Circuit for driving a liquid crystal (LCD) shutter to simply pass or block lightMiscDec 21, 2009Status0 vote up vote down
Linux Infra-red Remote Control (LIRC)PCApr 12, 2001Status-2 vote up vote down
Simple home made ADS-B receiver that takes IF from a modified receiverRFOct 04, 2010Status1 vote up vote down
Very Simple ADSB Receiver using a TV tunder to allow reception of aircraft transpondersRFOct 04, 2010Status0 vote up vote down
115200 RS232 QPSK RF modem projectRFOct 04, 2010Status0 vote up vote down
Build your own MARES dive computer IRIS interface for RS232PCOct 04, 2010Status-1 vote up vote down
3.3V / 5V Regulated Power Supply CircuitPowerJul 03, 2011Status2 vote up vote down
Acceleration Sensing - gesture controllers for robotic musical instrumentsModelsJan 09, 2010Status1 vote up vote down
Distance Sensing - devices for wireless distance and position determinationModelsJan 09, 2010Status0 vote up vote down
Doppler radar based gesture measurement system capable of delivering positional informationModelsJan 09, 2010Status0 vote up vote down
Infrared Body SensingIRJan 09, 2010Status0 vote up vote down
Homebuilt RS232 LCD InterfacePCJun 18, 2003Status-1 vote up vote down
Lie detectorMisc Status0 vote up vote down
Project to capture infrared remote control signals and play them back, based on Atmel ATMEGA48 microIRJan 17, 2010Status0 vote up vote down
MIDI Controller FootpedalMusicAug 14, 2002Status0 vote up vote down
DIY Serial MIDI Interface (80C51/80C31 Version)MusicAug 14, 2002Status0 vote up vote down
Homemade Serial to Nokia MBus Interface on a PCB, without using Zener diodesPC Status-1 vote up vote down
Microcontroller sensor and actuator interfacesMicrocontrollerApr 27, 2003Status-1 vote up vote down
Hi-Fi Preamp with remote-control and other advanced featuresPreamp Status-2 vote up vote down
Actvie speaker based on a dual op-amp (LM833) and TDA2030 power ampAmplifiers Status-3 vote up vote down
4 channel power amplifier with bi-amping and bridging optionsAmplifiers Status-1 vote up vote down
Amplifier based on LM4780 including a thermal shutdown featureAmplifiers Status-1 vote up vote down
Lead-Acid Battery MonitorPower Status0 vote up vote down
Complete Design for Giant 8-foot LCD Counter (Zip file)MicrocontrollerMar 27, 2009Status-1 vote up vote down
PIC12C509 logic gate replacement for nitrogen filler (ZIP file)MicrocontrollerMar 01, 2003Status-1 vote up vote down
PIC demo boardMicrocontrollerOct 31, 2002Status-1 vote up vote down
Disco light controller (ZIP file)LightingMar 01, 2003Status0 vote up vote down
DS1821 programmable thermostatControlMar 01, 2003Status-1 vote up vote down
PIC12C509 Gym Timer (ZIP file)MicrocontrollerMar 01, 2003Status-1 vote up vote down
PIC LCD and Keypad driverMicrocontrollerOct 31, 2002Status-2 vote up vote down
PIC12C508 Phase Controller for 2kW heater (ZIP file)MicrocontrollerMar 01, 2003Status-1 vote up vote down
PIC16F84 TRIAC / IGBT brightness phase controllerMicrocontrollerMar 01, 2003Status0 vote up vote down
PIC16F84 pulse monitor with date/time output (ZIP)MicrocontrollerMar 01, 2003Status-1 vote up vote down
Simple metal detector based on a PIC12F683 microcontrollerMetalJun 27, 2010Status-2 vote up vote down
Three component bat detector based on a PIC12F683 microcontrollerMiscJun 27, 2010Status-1 vote up vote down
Mini oscilloscope based on PIC18F4620 and standard 16x2 text LCD display moduleTestJun 27, 2010Status2 vote up vote down
PIC based touch clock that demonstrates interfacing a PIC microcontroller to an LCD touch panelMicrocontrollerJun 27, 2010Status-1 vote up vote down
Pico OSD, a PIC video superimposerVideoJun 27, 2010Status0 vote up vote down
A PIC16F84A Alarm ClockMicrocontrollerJun 27, 2010Status0 vote up vote down
PIC16F877A Thermometer with MCP9700A sensorData AcquisitionJun 27, 2010Status0 vote up vote down
A Voice Controlled LED Light Show using a VRStampMicrocontrollerJun 27, 2010Status-1 vote up vote down
PIC PAL Video Library including source code and circuit schematicsVideoJun 27, 2010Status0 vote up vote down
Cheap Ultrasonic Range Finder based on a PIC microcontrollerMicrocontrollerJun 27, 2010Status-1 vote up vote down
Cheap Ultrasonic Range Finder based on PIC16F877A with a 8MHz crystalMicrocontroller Status0 vote up vote down
A PIC16F819 Dymoclock (also demonstrates interfacing 30 LEDs to a PIC using only six I/O pins)MicrocontrollerJun 27, 2010Status-1 vote up vote down
MemoSound game based on a PIC16F84AGamesJun 27, 2010Status-2 vote up vote down
EasyPic2 with on-board Ethernet AdapterMicrocontrollerJun 27, 2010Status-1 vote up vote down
Automatic LED display dimmer using a LED as a light sensorLEDJun 27, 2010Status-2 vote up vote down
DCF-77 PIC LED clock (DCF77 is the name of a German radio station on 77.5 KHz)TimingJun 27, 2010Status0 vote up vote down
DCF77 PIC16F84A Single-Nixie clock (DCF77 is the name of a German radio station on 77.5 KHz)TubeJun 27, 2010Status0 vote up vote down
Yaesu FT-736R doppler compensationRFAug 14, 2002Status0 vote up vote down
AI-1 ("All-in-one") Remote - photographic accessory that you can buildPhoto Status0 vote up vote down
HeadBanger Headphone AmpAmplifiersJan 26, 2001Status-3 vote up vote down
Pad launch controller for model rocketsModelsJun 17, 2003Status0 vote up vote down
Stage center reverb unit circuit schematicMusicApr 14, 2010Status1 vote up vote down
Custom USB tyre pressure monitoring systemAutomotive Status-1 vote up vote down
Simple flashing light circuitModelsJan 26, 2001Status0 vote up vote down
Simple flashing light circuitModelsJan 26, 2001Status0 vote up vote down
A dual alternating flashing light circuitModelsJan 26, 2001Status-1 vote up vote down
Simple flashing light circuitModelsJan 26, 2001Status0 vote up vote down
A dual tandem flashing light circuit powered by a 9 volt batteryModelsJan 26, 2001Status0 vote up vote down
Simulate the Gyralite (dual flashing headlights).ModelsJan 26, 2001Status0 vote up vote down
Moderately complex train detector using an infrared LED and an infrared detectorModels Status0 vote up vote down
Simple train detector using ambient light and a photocellModelsJan 26, 2001Status0 vote up vote down
Aladin interfacePDAJun 13, 2002Status0 vote up vote down
Homemade GPS jammer using a MC145151 frequency synthesizerMiscJan 17, 2011Status-4 vote up vote down
Neon lamp dimmerLightingNov 17, 2002Status-1 vote up vote down
Microphone phantom power supplyAudioJan 31, 2003Status0 vote up vote down
AD9850 DDS daughterboardTestSep 21, 2006Status0 vote up vote down
30M PSK31 Transceiver circuit diagramRFFeb 25, 2003Status1 vote up vote down
SOP receiver (PDF)RFOct 30, 2002Status2 vote up vote down
SOP direct conversion receiverRFJan 06, 2002Status-1 vote up vote down
Popular Electronics Ultrasound DetectorMiscJan 01, 2003Status0 vote up vote down
PIC micro to ISA bus interfaceMicrocontrollerApr 17, 2004Status-1 vote up vote down
Balanced microphone preampPreampNov 01, 2002Status2 vote up vote down
Machine Independent Parallel InterfacePC Status-1 vote up vote down
Navigator 555A radio direction finder (RDF) circuit diagramMiscMay 01, 2004Status0 vote up vote down
Signal Tracer and InjectorTestSep 13, 2006Status-2 vote up vote down
80188XL Engine Tachometer / Race ComputerAutomotiveOct 24, 2002Status-1 vote up vote down
TDS/PPM Meter for measuring of the amount of salts in a solutionTestMar 29, 2009Status0 vote up vote down
Laser Modem with an Arduino MicrocontrollerArduinoNov 13, 2010Status-2 vote up vote down
24" Wall ClockTiming Status0 vote up vote down
Linuxstamp general purpose processor module based on Atmel AT91RM9200Microcontroller Status-1 vote up vote down
PG31 GPS RS232 GPS development boardPC Status-1 vote up vote down
PG31 GPS RS232 USB development boardPC Status-1 vote up vote down
PointLess LED Array - A 8 by 8 array displays something using POVLED Status0 vote up vote down
A "persistence of vision display" (POV display) using LEDsLED Status1 vote up vote down
PC to microcontroller communications using power from the PC serial portMicrocontroller Status-1 vote up vote down
RS232 RS485 USB Converter BoardPC Status-1 vote up vote down
PalmPilot turbo boost guage interfacePDAApr 27, 2003Status0 vote up vote down
1.5V iPod Microphone (PDF)PDASep 25, 2009Status1 vote up vote down
Inverter for fluorescent lights as published in Silicon Chip Magazine February 1991 (PDF)LightingAug 18, 2009Status0 vote up vote down
Solar switching regulator as published in Silicon Chip Magazine January 1994 Part 1/2 (PDF)SolarAug 18, 2009Status-2 vote up vote down
Solar switching regulator as published in Silicon Chip Magazine January 1994 Part 2/2 (PDF)SolarAug 18, 2009Status-1 vote up vote down
LDR light/dark activated relay switchControlJun 17, 2003Status-1 vote up vote down
Dual Voltage Controlled Oscillator w/ModulatorAudioJun 08, 2002Status0 vote up vote down
Spring reverbMusicJun 08, 2002Status0 vote up vote down
MS Stereo DecoderAudioJun 08, 2002Status-1 vote up vote down
Drum percussion sensor schematicsMusicMar 05, 2009Status-1 vote up vote down
2 Note Ribbon ControllerMusicMar 05, 2009Status0 vote up vote down
4 Bit Digitizer / flash ADC using discrete componentsData AcquisitionMar 05, 2009Status0 vote up vote down
Using the Hot Springs Reverb reverberation unitMusicMar 05, 2009Status0 vote up vote down
midi2cv8 to Drum Tone Board ConnectionsMusicMar 05, 2009Status-1 vote up vote down
Practical MS Decoder CircuitMusicMar 05, 2009Status1 vote up vote down
Drum Tone OscillatorsMusicMar 05, 2009Status-2 vote up vote down
Theremax Theramic Circuit SchematicMusicMar 05, 2009Status0 vote up vote down
Touch switchesMiscMar 05, 2009Status-1 vote up vote down
Vocal zapperMusicJun 08, 2002Status-2 vote up vote down
Headphone monitor ampAmplifiersJun 08, 2002Status-3 vote up vote down
RIAA Equalized Stereo Phono PreampPreampJun 08, 2002Status-1 vote up vote down
Theremin controllerMusicJun 08, 2002Status2 vote up vote down
Touch SwitchesControlJan 26, 2001Status-1 vote up vote down
6090 digital decoder schematicsControlOct 30, 2002Status-2 vote up vote down
White LED circuitsLEDOct 13, 2002Status0 vote up vote down
Electroluminescent Receiver Kit includes circuit diagramRF Status1 vote up vote down
Receiver based on NE602RFJan 26, 2001Status0 vote up vote down
Build your own UFO Bino-Scope unit - upgrade binoculars to become a photosensitive bino-scopeMisc Status0 vote up vote down
Controlling your SLR Camera from an IpodPhotoMay 09, 2010Status0 vote up vote down
Deriving power from Lego NXT motor port AModels Status0 vote up vote down
External power supply for Lego NXTModels Status0 vote up vote down
Color sensor circuitMisc Status0 vote up vote down
Wire guidance sensorModels Status1 vote up vote down
GP2D12 distance sensorModels Status0 vote up vote down
Infrared lampIR Status0 vote up vote down
Laser Target Finder SensorLaserOct 06, 2006Status0 vote up vote down
Lego compatible, compact rotation sensorModels Status0 vote up vote down
DC40 - 40M Direct Conversion receiverRFOct 08, 2009Status-1 vote up vote down
SSB linear amplifier made from a bunch of 2N2218 transistorsRF_AmplifierOct 08, 2009Status0 vote up vote down
Homebrew signal generator tunable from 3 to 30 MhzTestOct 08, 2009Status0 vote up vote down
Simple Dual Band SSB Transceiver (20/40 meters)RFOct 08, 2009Status-1 vote up vote down
PASCO scientific model SF-9211 stroboscope schematic (PDF)Misc Status0 vote up vote down
Microchip PIC ICD (in-circuit debugger)MicrocontrollerJun 18, 2003Status-2 vote up vote down
Variety of circuits for RS232 to TTL Signal ConversionMicrocontroller Status-1 vote up vote down
Variety of circuits for TTL to RS232 Signal ConversionMicrocontroller Status-1 vote up vote down
Smooth, fast, strong and cheap stepper motor controller using a PIC microControlNov 04, 2011Status-1 vote up vote down
Tony Nixons Pocket Programmer (PIC)ProgrammersOct 13, 2002Status0 vote up vote down
Simple switching power supplyPowerJul 10, 2002Status-1 vote up vote down
Selection of PWM driver circuits for electric DC motorsControlNov 05, 2009Status-1 vote up vote down
PicoWeb V5.1 (AT90S8515) tiny web serverMicrocontrollerJan 31, 2003Status-1 vote up vote down
RDS EncoderAudioMar 27, 2009Status-1 vote up vote down
Mass storage and printer interface for the FX-700P calculatorPDA Status0 vote up vote down
MP3 Player circuit schematicMusicMay 30, 2007Status1 vote up vote down
Atmel 89C2051 In-Circuit Programmer SchematicProgrammersJun 20, 2004Status0 vote up vote down
8051 Development System Circuit BoardMicrocontrollerSep 13, 2006Status-1 vote up vote down
8051 Development System Circuit BoardMicrocontrollerOct 23, 2002Status-1 vote up vote down
8051 Development System Circuit BoardMicrocontrollerAug 14, 2002Status-2 vote up vote down
50W audio power amplifier circuit diagramAmplifiersJun 20, 2004Status-4 vote up vote down
CCD linear image sensor to PC parallel interfacePCJun 20, 2004Status-1 vote up vote down
MIDI drum machine projectMusicJun 20, 2004Status0 vote up vote down
MIDI Drum Machine Analog Input SchematicMusicApr 27, 2003Status-1 vote up vote down
Microprocessor using Xilinx FPGAMicrocontrollerJun 20, 2004Status-1 vote up vote down
Arduindo based Appliance Remote ControlControlJun 20, 2010Status-1 vote up vote down
Online thermometer based on an ArduinoArduinoJun 20, 2010Status-2 vote up vote down
PS/2 Keyboard Or Mouse based on an ArduinoArduinoJun 20, 2010Status-1 vote up vote down
RFID Access Control System based on an ArduinoArduinoJun 20, 2010Status0 vote up vote down
Oscilloscope / Logic Analyzer based on an ArduinoArduinoJun 20, 2010Status-2 vote up vote down
Arduino Based Security / Automation SensorsArduinoJun 20, 2010Status1 vote up vote down
Arduino speech sythesizerArduinoJun 20, 2010Status-2 vote up vote down
Arduino based Time-Lapse Camera ControllerArduinoJun 20, 2010Status-1 vote up vote down
Interfacing an LCD touch control panel to an ArduinoArduinoJun 20, 2010Status0 vote up vote down
Vehicle Telemetry Platform based on an ArduinoArduinoJun 20, 2010Status-1 vote up vote down
Virtual USB Keyboard based on an ArduinoArduinoJun 20, 2010Status-1 vote up vote down
Arduino based water flow guageArduinoJun 20, 2010Status-3 vote up vote down
Water Tank Depth Sensor based on an ArduinoArduinoJun 20, 2010Status-2 vote up vote down
Weather Station Receiver based on an Arduino and 433MHz RF receiver moduleArduinoJun 20, 2010Status-1 vote up vote down
Temperature controlled based on AT89CX051MicrocontrollerJan 26, 2001Status-2 vote up vote down
Sallen-Key Active Butterworth High Pass Filter Calculator and circuit diagramFilterJan 16, 2010Status0 vote up vote down
Sallen-Key Active Butterworth Low Pass Filter Calculator and circuit diagramFilterJan 16, 2010Status0 vote up vote down
MIDI Pedalboard encoder circuit diagram and background informationMusic Status0 vote up vote down
Tone Filters for Electronic Organs (PDF)Music Status-1 vote up vote down
40m band direct conversion receiverRFJan 06, 2002Status0 vote up vote down
80m band direct conversion receiverRFJan 06, 2002Status-2 vote up vote down
AC Power MeterPower Status-2 vote up vote down
Remote Motor ControllerControl Status-1 vote up vote down
Precision Frequency MarkerTest Status1 vote up vote down
Simple Inductance MeterTest Status0 vote up vote down
Regenerative Short Wave RadioRF Status0 vote up vote down
Sleep TimerTiming Status0 vote up vote down
Super VXOTiming Status0 vote up vote down
Homebrew 20m CW TransceiverRF Status-1 vote up vote down
Homebrew 30m CW TransceiverRF Status1 vote up vote down
Homebrew 40m CW TransceiverRF Status1 vote up vote down
Homebrew 6m SSB/CW TransceiverRF Status0 vote up vote down
Homebrew 6m DSB TransceiverRF Status-1 vote up vote down
TV RGB signal output from a SVGA graphics cardVideoApr 14, 2003Status1 vote up vote down
High Precision GPS/TV controlled Reference OscillatorTimingMay 01, 2004Status0 vote up vote down
u-Blox GPS receiver boardMiscMar 23, 2003Status0 vote up vote down
I2C LCD interfaceMicrocontrollerMay 01, 2004Status-1 vote up vote down
TV based Receiver for a Standard Frequency GeneratorTimingMay 01, 2004Status0 vote up vote down
FPGA Based ADS-B Receiver and DecoderRFDec 09, 2010Status0 vote up vote down
ADMS programming Cable for the Yaesu FT50, VX1 and VX5PCMay 07, 2010Status0 vote up vote down
Radio Interface Box for the Motorola Radius GP300PCMay 07, 2010Status-1 vote up vote down
PG4S programming Cable for the Kenwood TM-V7 and TM-G707PCMay 07, 2010Status0 vote up vote down
Laptop Computer Serial Port Power BoosterPCApr 12, 2001Status-1 vote up vote down
SPDIF RCA to (Optical + RCA) AdapterPCMay 07, 2010Status-1 vote up vote down
136 kHz direct conversion receiverRFJan 06, 2002Status0 vote up vote down
Chebyshev / Butterworth filtersFilterJun 13, 2002Status0 vote up vote down
AFSK 1200 Modem based on PIC16C620MicrocontrollerJul 10, 2002Status0 vote up vote down
PicCon - Hidden Radio Transmitter ControllerMicrocontrollerJul 10, 2002Status0 vote up vote down
Audible S-MeterRF Status0 vote up vote down
40 Segment LED S-Meter circuit diagramRF Status0 vote up vote down
Bi-Directional 2.4 GHz One Watt AmplifierRF_AmplifierJun 13, 2002Status-1 vote up vote down
Bi-Directional 900Mhz One Watt AmplifierRF_AmplifierJun 13, 2002Status0 vote up vote down
20 Watt GaAaFET Power on 2.3 GHzRFJun 13, 2002Status0 vote up vote down
1 Watt 2.3 GHz RF Amplifier Using a MRF2001RF_AmplifierJun 13, 2002Status0 vote up vote down
One Watt 2.45 GHz Linear Amplifier using RF Micro Devices RF2126RF_AmplifierOct 31, 2002Status-1 vote up vote down
VCR Tuner Based RF Spectrum Analyzer SchematicTestSep 21, 2006Status0 vote up vote down
2.3 GHz Power AmplifiersRF_AmplifierJun 13, 2002Status0 vote up vote down
2304 and 3456 MHz Power AmplifiersRF_AmplifierJun 13, 2002Status0 vote up vote down
LCD frequency counter (PIC16F84)TestNov 29, 2002Status1 vote up vote down
AD9852 DDS schematicTimingFeb 14, 2003Status0 vote up vote down
High Frequency VCO Design and SchematicsRFOct 25, 2014Status1 vote up vote down
Dopler RDF (radio direction finder) circuitRF Status0 vote up vote down
Biquad Active Bandpass Filter SchematicFilterNov 01, 2002Status-1 vote up vote down
VFO from 2001 ARRL Handbook, page 17.74RFNov 01, 2002Status1 vote up vote down
VFO from 2001 ARRL Handbook, page 14.20RFNov 01, 2002Status0 vote up vote down
Various sound card interfacing circuit diagramsPC Status-1 vote up vote down
Assorted relay control circuitsControlMar 18, 2003Status-2 vote up vote down
Assorted computer interface circuitsPCMar 18, 2003Status-2 vote up vote down
Assorted digital circuitsMiscMar 18, 2003Status0 vote up vote down
Basic opamp circuitsMiscMar 18, 2003Status0 vote up vote down
Assorted LED circuitsLEDMar 18, 2003Status0 vote up vote down
Miscellaneous simple circuitsMiscMar 18, 2003Status0 vote up vote down
Assorted power source and control circuitsPowerMar 18, 2003Status-1 vote up vote down
Assorted RF circuitsRFMar 18, 2003Status0 vote up vote down
Assorted telephone circuits (ring generator, in-use indicator, audio interface)TelephoneMar 18, 2003Status-1 vote up vote down
PIC16F84 tone generator with source codeMicrocontrollerMar 01, 2003Status0 vote up vote down
PIC16F84 tone generatorMicrocontrollerJul 10, 2002Status0 vote up vote down
PIC16F84 tone generator (6-Bit)MicrocontrollerJul 10, 2002Status0 vote up vote down
14MHz SSB 10mW TransceiverRFFeb 24, 2003Status0 vote up vote down
Decimal DDS Signal GeneratorTiming Status0 vote up vote down
Apple II/II+/IIe IDE Drive InterfacePCOct 31, 2002Status-1 vote up vote down
Circuits to transmit and demoludate RF / video signals over fibre optic cableVideo Status0 vote up vote down
Space invaders game using PIC microcontrollerGamesOct 06, 2006Status0 vote up vote down
High quality exponential VCAAmplifiersApr 17, 2004Status-4 vote up vote down
VLF radio receiver schematicRFApr 17, 2004Status4 vote up vote down
VLF Upconverter for Shortwave ReceiverRFSep 13, 2006Status0 vote up vote down
Accelerometer SchematicData AcquisitionOct 31, 2002Status0 vote up vote down
Basic Vox CircuitRF Status0 vote up vote down
Build A 100Khz Crystal CalibratorTiming Status0 vote up vote down
Build A Simple Rechargeable CMOS BatteryPower Status-1 vote up vote down
Variable Bandwidth CW FilterRF Status0 vote up vote down
Simple electronic keyerMisc Status-1 vote up vote down
An Inexpensive Tone EncoderRF Status0 vote up vote down
Build A High Performance Voltage Regulator From Discrete ComponentsPower Status-1 vote up vote down
Thermal cooling fan controllerControl Status-1 vote up vote down
FM Morse Code KeyerMisc Status0 vote up vote down
12 Volt Gel Cell Charger circuit diagramPower Status-1 vote up vote down
Selection of Integrated Circuit Audio AmplifiersAmplifiers Status-4 vote up vote down
Improved PL tone decoderAudioJan 26, 2001Status0 vote up vote down
Easy Morse Code Keyer CircuitMisc Status-1 vote up vote down
Build A 10 Amp 13.8 Volt Power SupplyPower Status4 vote up vote down
Adjustable Voltage Regulator using a 7805 or other fixed linear voltage regulator instead on LM317Power Status-1 vote up vote down
5 watt, 80 meter QRP CW TransceiverRFJun 08, 2002Status0 vote up vote down
Simple electronic S meterTest Status0 vote up vote down
Audio Speech ProcessorAudio Status-1 vote up vote down
CW Tone KeyerMisc Status0 vote up vote down
Potpourri of Transistor Audio Amplifier CircuitsAmplifiers Status-1 vote up vote down
40 Meter, 5 Watt QRP Transmitter circuit diagramTransmitters Status-1 vote up vote down
Using Pass Transistors Beef Up Voltage Regulator current outputPower Status-2 vote up vote down
R/C digital camera controllerModelsMar 01, 2003Status1 vote up vote down
Digital Call Sign AnnunciatorMiscJun 09, 2002Status0 vote up vote down
R/C helicopter cameraModelsOct 30, 2002Status0 vote up vote down
Monitor output from Motorola Oncore GPS engine in HP Z3801A in GPS Disciplined OscillatorMiscMay 01, 2004Status0 vote up vote down
16 Watt audio amplifier using pair of 8 watt LM383 audio amplifier chipsAmplifiersJan 26, 2001Status-4 vote up vote down
8 watt amplifier circuit diagramAmplifiersJan 26, 2001Status-5 vote up vote down
Magnetic cartridge amplifierAmplifiersJan 26, 2001Status-1 vote up vote down
Electret mic amplifierPreampJan 26, 2001Status2 vote up vote down
Audio preamplifierPreampJan 26, 2001Status-12 vote up vote down
LM358 preamp circuit diagramPreampJan 26, 2001Status-1 vote up vote down
Sound detector circuit diagramAudioJan 26, 2001Status-2 vote up vote down
Tone detector circuit diagramAudioJan 26, 2001Status-1 vote up vote down
Tone generator circuit diagramAudioJan 26, 2001Status-1 vote up vote down
Warbler siren circuit diagramAudioJan 26, 2001Status-1 vote up vote down
40khz IR Tester circuit diagramIRJan 26, 2001Status0 vote up vote down
555 timer 40khz IR OscillatorIRJan 26, 2001Status0 vote up vote down
Basic IR detector / emitter circuit diagramIRJan 26, 2001Status1 vote up vote down
Ultrasonic switch transmitter and receiver circuit diagramMiscJan 26, 2001Status0 vote up vote down
12 volt battery monitor circuit diagramPowerJan 26, 2001Status-1 vote up vote down
12 volt power supply circuit diagramPowerJan 26, 2001Status-1 vote up vote down
5 volt power supply circuit diagramPowerJan 26, 2001Status1 vote up vote down
Battery voltage monitor circuit diagramPowerJan 26, 2001Status0 vote up vote down
LM3914 battery monitor circuit diagramPowerJan 26, 2001Status-2 vote up vote down
Multiple voltage power supplyPowerJan 26, 2001Status-3 vote up vote down
Voltage doubler using a 555 timerPowerJan 26, 2001Status0 vote up vote down
Voltage inverter using a 555 timerPowerJan 26, 2001Status-2 vote up vote down
Miniature FM transmitter circuit diagramTransmittersJan 26, 2001Status0 vote up vote down
Sensitive FM transmitter circuit diagramTransmittersJan 26, 2001Status0 vote up vote down
Simple RF transmitter circuit diagramTransmittersJan 26, 2001Status0 vote up vote down
1.5 volt tracking transmitter circuit diagramTransmittersJan 26, 2001Status0 vote up vote down
Tracking transmitter circuit diagramTransmittersJan 26, 2001Status2 vote up vote down
Speech Amplifier BoxAmplifiers Status-4 vote up vote down
Mini-MosFet Audio AmplifierAmplifiersMar 05, 2009Status-6 vote up vote down
Compact DJ stationMusicMar 05, 2009Status0 vote up vote down
Plant Watering Watcher (moisture meter)Misc Status0 vote up vote down
Automated crib light circuit diagramLighting Status1 vote up vote down
Sound pressure level meter circuit diagramAudio Status-1 vote up vote down
Sensor Electronic Tracker with H-Bridge DriveSolarJun 07, 2002Status0 vote up vote down
Sensor Electronic Tracker with Simple Solar Charge ControllerSolarJun 07, 2002Status0 vote up vote down
Solar tracking control systemSolarNov 16, 2002Status-3 vote up vote down
LED7 solar tracker circuit diagramSolarNov 16, 2002Status1 vote up vote down
Macrovision removal - includes circuit diagram and background informationVideoJan 01, 2003Status-2 vote up vote down
Pressure Sensor-Based Altimeter CircuitData AcquisitionApr 27, 2003Status1 vote up vote down
Build a good GaAs FET preamp for 2 meters, 222MHz or 440MHzRF_Amplifier Status-1 vote up vote down
An Audio Limiter for NBFM useAudio Status-1 vote up vote down
Crystal heater / temperature stablization circuit (TXCO)Timing Status-1 vote up vote down
An Audio-Noise-Based Voting CircuitAudio Status-1 vote up vote down
Low power audio amplifier circuit based on LM386AmplifiersJan 29, 2010Status-3 vote up vote down
LED dimmer circuitLED Status-1 vote up vote down
Build a DIY solar iPod chargerSolarMay 30, 2007Status-2 vote up vote down
Virtual Game System - A game console with a mechanically scanned displayGames Status1 vote up vote down
AVR Color Clock using RGB LEDsLED Status0 vote up vote down
PIC10F200-based electronic diceGames Status0 vote up vote down
PIC16F84-based video game systemGames Status0 vote up vote down
Generate video signals in software using PICVideo Status0 vote up vote down
SX28-based color video game systemGames Status0 vote up vote down
Generate composite color video signals in software using an SX microcontrollerVideo Status0 vote up vote down
DIY Plasma Globe using an automotive ignition coilMisc Status0 vote up vote down
DIY Power Pulse ControllerControl Status-1 vote up vote down
DIY Tesla coil - DC Powered with Plasma OutputMisc Status0 vote up vote down
Circuit diagram for connecting the SRF08/10/235 sonar modules to the BS2p Basic StampModels Status0 vote up vote down
Alphanumeric Led Display ProjectLEDNov 02, 2010Status0 vote up vote down
H-Bridge Motor Driver Using Bipolar TransistorsControlAug 12, 2009Status-3 vote up vote down
Dual fan controller using ATTiny45 microcontrollerControlNov 02, 2010Status-1 vote up vote down
Standalone LED testerTestNov 02, 2010Status0 vote up vote down
DC Motor-Driver H-Bridge CircuitControlJun 09, 2002Status-1 vote up vote down
Infrared Transmitter Project Implemented on a Solderless BreadboardIRNov 02, 2010Status0 vote up vote down
Model rocket launch controllerModelsNov 02, 2010Status0 vote up vote down
How to Make a PWM Circuit without a MicrocontrollerControlAug 12, 2009Status-1 vote up vote down
How to Control LED Brightness with a PWM Circuit using a 74AC14LEDApr 17, 2011Status-1 vote up vote down
Making an Amplified Color Sensor from an LED and an Op AmpLED Status0 vote up vote down
Schematic and breadboard layout for reversed LED color sensor using an opampLEDAug 12, 2009Status1 vote up vote down
Making a FRED photopopperModels Status0 vote up vote down
Simple switching regulator (experimental)PowerNov 16, 2002Status-1 vote up vote down
RS232 interfaced DVM using a PIC12F675 including source code for CCS C CompilerMicrocontrollerSep 09, 2009Status0 vote up vote down
A GPS receiver based frequency standardTimingMar 23, 2003Status0 vote up vote down
Build a breadboard power module for integrated circuitsPowerSep 30, 2009Status-1 vote up vote down
Speaker cabinet simulator - professional-quality frequency response in a DIY-friendly circuitAudioSep 30, 2009Status-1 vote up vote down
Two channel distortion circuitMusic Status2 vote up vote down
Marshall 18W adapted for use as a distortion stompboxMusicSep 30, 2009Status0 vote up vote down
Vox AC-30 Top Boost adapted for use as a distortion stompboxMusicSep 30, 2009Status0 vote up vote down
Closer look at the FET booster based on a vintage Fender 12AX7 input stage.Tube Status-1 vote up vote down
Ampeg SB-12 Portaflex adapted for use as a bass overdrive stompboxMusicSep 30, 2009Status0 vote up vote down
Distortion effects using an LM386 audio amplifier ICMusicSep 30, 2009Status1 vote up vote down
Two 9v battery-powered amps based on the LM386. Schematic and PCB/perfboard layouts.Amplifiers Status0 vote up vote down
Matchless DC/30 adapted for use as a distortion stompboxMusicSep 30, 2009Status0 vote up vote down
Treble Booster/Overdrive including a perf board circuit layoutMusicSep 30, 2009Status0 vote up vote down
Schematic of a Rockman-like distortion. Schematic and PCB/perfboard layouts.Music Status0 vote up vote down
Mr. EQ - a simple, yet potent DIY equalizerMusicSep 30, 2009Status1 vote up vote down
New clipper circuit diagram (based on TL071 opamp)MusicSep 30, 2009Status0 vote up vote down
Versatile FET booster engine. Schematic and perfboard/PCB layouts.Music Status-1 vote up vote down
Peppermill overdrive - A simple, transparent overdrive. Schematic and PCB/perfboard layouts.MusicSep 30, 2009Status0 vote up vote down
Faux-phaser circuit with LFO and manual (wah pedal) modes. Schematic and and PCB layout.MusicSep 30, 2009Status0 vote up vote down
Fender Princeton adapted for use as a distortion stompboxMusic Status0 vote up vote down
Ruby is an "enhanced" version of the Little Gem battery-powered amplifier (LM386 based design)AmplifiersSep 30, 2009Status-1 vote up vote down
Supro 16T adapted for use as a distortion stompboxMusicSep 30, 2009Status0 vote up vote down
Dual parallel buffered effect loops with blend control. Schematic and perfboard/PCB layoutsMusic Status1 vote up vote down
Marshall 100W Super Lead adapted for use as a distortion stompbox. Schematic and PCB layout.MusicSep 30, 2009Status1 vote up vote down
An ultra-flexible tonestack with clean boost. Schematic, photo, and PCB/perfboard layouts.MusicSep 30, 2009Status0 vote up vote down
Tube Screamer-based overdrive. Schematic and PCB/perfboard layouts.Tube Status1 vote up vote down
Umble - A distortion stompbox, inspired by Dumble amplifiers. Schematic and PCB/perfboard layouts.MusicSep 30, 2009Status-1 vote up vote down
Boogie MkI adapted for use as a distortion stompboxMusic Status-1 vote up vote down
Two Transistor Reflex RadioRFAug 17, 2009Status1 vote up vote down
LED flasher using 4584 hex inverting Schmitt triggerLEDAug 17, 2009Status1 vote up vote down
Sound operated switchAudioAug 17, 2009Status-1 vote up vote down
Low power audio amplifier using BC109C along with BD679 and BD680 Darlington pairsAmplifiers Status-3 vote up vote down
Long duration timer using 4060 12-stage binary ripple counterTimingAug 17, 2009Status0 vote up vote down
Infrared headphone system (includes transmistter and receiver schematics along with vero layout)IRAug 17, 2009Status1 vote up vote down
Simple stepper motor driver for PC parallel portPC Status-1 vote up vote down
Optically isolated TRIAC driverControlAug 17, 2009Status-1 vote up vote down
Reaction timer using 4013 flip-flop and 4060 12-stage binary ripple counterGamesAug 17, 2009Status0 vote up vote down
10 watt audio power amplifier using discrete transistors (includes PCB layout)Amplifiers Status-1 vote up vote down
TRIAC based lamp dimmer circuit diagramLightingAug 17, 2009Status2 vote up vote down
StroboscopeMiscAug 17, 2009Status0 vote up vote down
8049 Spy - read the internal ROM contents of a 8048 or 8049 processorMicrocontrollerSep 25, 2009Status0 vote up vote down
MS-DOS EEPROM ProgrammerPCSep 25, 2009Status-1 vote up vote down
Fluke 8010 / 8012 InterfaceTestSep 25, 2009Status0 vote up vote down
6802 Nano computerMicrocontrollerSep 25, 2009Status0 vote up vote down
Nikon IR-Remote Control based on Atmel ATtiny13PhotoSep 25, 2009Status0 vote up vote down
SAA1064 display module projectLEDSep 25, 2009Status0 vote up vote down
SB-Bus Drivers Introduction and Circuit DiagramsPCSep 25, 2009Status-1 vote up vote down
AVR STK200/STK300 ISP Dongle circuit diagramMicrocontrollerSep 25, 2009Status0 vote up vote down
Tiny Eprom SimulatorMicrocontrollerSep 25, 2009Status0 vote up vote down
UTP Cable TesterTestSep 25, 2009Status-2 vote up vote down
PC based biofeedback monitorMedical Status3 vote up vote down
Camera remote control system using Basic StampPhotoMay 01, 2004Status0 vote up vote down
Audio Detector CircuitAudioOct 06, 2006Status0 vote up vote down
RF Modem Robotics ProjectModelsJan 06, 2002Status-1 vote up vote down
Real-time Laser Range Finding Vision SystemLaserOct 06, 2006Status0 vote up vote down
10Hz - 100KHz D.D.S. Function GeneratorTestSep 21, 2006Status0 vote up vote down
RS-232 to TTL cablePCMay 01, 2004Status-1 vote up vote down
Very basic circuitsMiscJan 26, 2001Status-1 vote up vote down
Implementing Infrared Object DetectionIRJan 26, 2001Status0 vote up vote down
R2T2 Haywire Home StationRFOct 07, 2009Status0 vote up vote down
ICOM CI-V interface with RS232 RTS to PTTRFMay 01, 2004Status1 vote up vote down
Bat detectorMiscJan 26, 2001Status0 vote up vote down
30-Meter QRP Transmitter for Morse CodeTransmittersJan 26, 2001Status0 vote up vote down
3rd brake light circuit diagramAutomotiveJan 26, 2001Status-1 vote up vote down
DC to AC inverter using a 555 timerPower Status1 vote up vote down
555 Timer IC Tester circuit diagramTestJan 26, 2001Status1 vote up vote down
555 go / no-go tester circuit diagramTestJan 08, 2002Status-1 vote up vote down
Dual (postive and negative) 12V power supplyPower Status2 vote up vote down
Active Antenna AA-7 HF/VHF/UHF, 3-3000MHzRF Status-2 vote up vote down
Active antenna 1 to 20dB, 1-30 MHz rangeRF Status-1 vote up vote down
Active Antenna for AM-FM-SWRF Status-1 vote up vote down
FM radio active antennaRF Status-1 vote up vote down
Light / dark activated relayControlJan 26, 2001Status-1 vote up vote down
Touch activated alarm systemAlarmsJan 26, 2001Status-2 vote up vote down
Current booster for 78nn series voltage regulatorsPower Status0 vote up vote down
Aviation band receiverRF Status-1 vote up vote down
Car backup / reversing alarmAutomotive Status0 vote up vote down
12V Lead-Acid Battery Monitor using LM3914PowerJan 08, 2002Status0 vote up vote down
Battery Tester for 1.5 and 9VTest Status1 vote up vote down
Charger for gel lead acid batteriesPowerJan 26, 2001Status0 vote up vote down
Broadcast-Band RF AmplifierRF_Amplifier Status-5 vote up vote down
Bug detector with beep using 7413 or 74LS13RFJan 26, 2001Status0 vote up vote down
Bug detector / countersurveillance monitorRF Status0 vote up vote down
Electronic canary doorbellMisc Status0 vote up vote down
12V to 9V car coverter circuit diagramAutomotiveJan 26, 2001Status-2 vote up vote down
Clock generatorTimingJan 26, 2001Status0 vote up vote down
Continuity tester V2 circuit diagramTestJan 26, 2001Status0 vote up vote down
Continuity tester circuit diagramTestJan 26, 2001Status0 vote up vote down
Coin tosserGamesOct 06, 2006Status0 vote up vote down
Compressor-mate power protection for refrigerators, freezers and air conditionersPowerOct 06, 2006Status0 vote up vote down
Cut phone line detectorTelephoneJan 08, 2002Status0 vote up vote down
DSL / ADSL phone line filterTelephone Status0 vote up vote down
Waterpump Safety Guard for fish pond / fish tankAlarms Status-1 vote up vote down
Third brake light pulser circuitAutomotive Status-1 vote up vote down
Miniature FM Transmitter #1TransmittersJan 26, 2001Status-1 vote up vote down
Miniature FM Transmitter #2TransmittersJan 26, 2001Status-1 vote up vote down
Miniature FM Transmitter #3TransmittersJan 26, 2001Status-1 vote up vote down
4-transistor transmitter circuit diagramTransmittersOct 06, 2006Status0 vote up vote down
FM telephone transmitterTransmittersOct 06, 2006Status0 vote up vote down
Electronic dazerMisc Status-1 vote up vote down
High voltage DC generatorPower Status0 vote up vote down
High-Voltage Pulse GeneratorPower Status1 vote up vote down
Jacob's LadderMisc Status-2 vote up vote down
Lightning bulb - Create an electrical storm in a light bulbLighting Status-1 vote up vote down
Negative Ion DetectorMisc Status-2 vote up vote down
Negative Ion GeneratorMisc Status0 vote up vote down
Tesla coilMisc Status0 vote up vote down
Solid state tesla coilMisc Status0 vote up vote down
High voltage zappersMisc Status-4 vote up vote down
Motorcycle battery chargerAutomotive Status-3 vote up vote down
Lamp flasher/dimmerLightingJan 26, 2001Status-1 vote up vote down
Miniature tracking transmitterTransmittersOct 06, 2006Status0 vote up vote down
Motorcycle low battery voltage warning circuitAutomotive Status-2 vote up vote down
Morse Code Practice Keyer 1MiscJan 26, 2001Status-1 vote up vote down
Morse Code Practice Keyer 2MiscJan 26, 2001Status-1 vote up vote down
Motorcycle brake light flasherAutomotive Status0 vote up vote down
Motorctcle turning signal systemAutomotive Status-2 vote up vote down
Automatic 9V NiCad battery chargerPower Status0 vote up vote down
9-pin null modem cablePCJan 26, 2001Status-2 vote up vote down
Audio preampPreampJan 26, 2001Status0 vote up vote down
Logic probeTestJan 26, 2001Status-1 vote up vote down
Pulse width modudulator using 555 timer ICControlAug 03, 2009Status-2 vote up vote down
Active Power ZenerPower Status-1 vote up vote down
Sound activated relay, V1Audio Status-1 vote up vote down
Sound activated relay, V2Audio Status-1 vote up vote down
Basic RF oscillatorRFJan 26, 2001Status-2 vote up vote down
Light sensing RF transmitterTransmittersJan 26, 2001Status0 vote up vote down
ScanMate audio activated recordedMicrocontrollerJan 26, 2001Status0 vote up vote down
Subcarrier adapter to listen to hidden subcarrier signals on FM radioRF Status1 vote up vote down
Water-level sensorData AcquisitionJan 26, 2001Status1 vote up vote down
741 Light SensorMiscJan 26, 2001Status-1 vote up vote down
Fluid level detectorMiscJan 26, 2001Status2 vote up vote down
Solid state relay circuitPower Status-1 vote up vote down
Simplest R/C circuitModels Status-2 vote up vote down
ThereminMusic Status-1 vote up vote down
Touch switch using transistorsMisc Status-1 vote up vote down
1.5V tracking transmitter circuit diagramTransmittersOct 06, 2006Status-1 vote up vote down
Micro-Spy with FETsTransmittersJan 26, 2001Status1 vote up vote down
Micro-Spy with USWTransmittersJan 26, 2001Status0 vote up vote down
Micro-Spy with TTLTransmittersJan 26, 2001Status0 vote up vote down
Wailing alarm sirenAlarms Status-1 vote up vote down
Wireless microphoneTransmittersOct 06, 2006Status1 vote up vote down
Christmas lights testerLightingOct 06, 2006Status-1 vote up vote down
555 Timer Tutorial + CircuitsTimingJan 26, 2001Status0 vote up vote down
Car Nicad chargerAutomotiveJan 26, 2001Status-1 vote up vote down
NiCad Discharger for Tx & Rx PacksPower Status1 vote up vote down
Glowplug driver for radio control modelsModels Status0 vote up vote down
Lead acid battery charger with floatPower Status1 vote up vote down
Simple constant current sourcePower Status0 vote up vote down
Solar cell Nicad charger using Maxim MAX639SolarJan 26, 2001Status2 vote up vote down
Two tone train hornModelsJan 26, 2001Status0 vote up vote down
Low cost Atmel in-system programmerProgrammersApr 17, 2004Status0 vote up vote down
Ultra low-cost programmer for AT90S familyProgrammersApr 17, 2004Status0 vote up vote down
AVR (AT90S2313) composite PAL colour bar generatorVideoApr 17, 2004Status-1 vote up vote down
Connecting AT90S2313 with LCD display 2x16 char and 4x4 keypadMicrocontrollerApr 17, 2004Status0 vote up vote down
Electronic safety lock based on ATtiny26MicrocontrollerApr 17, 2004Status0 vote up vote down
Greek telecard readerTelephoneApr 17, 2004Status0 vote up vote down
128x64 LCD Driver for AT90S2313 (ZIP file)MicrocontrollerApr 17, 2004Status0 vote up vote down
1-Wire Barometer projectData Acquisition Status0 vote up vote down
Simple pH Meter Circuit, A Low Cost Adapter for Your Digital VoltmeterTestNov 02, 2010Status0 vote up vote down
Connecting LED to PIC Micro I/O pins (PDF)MicrocontrollerNov 17, 2002Status-1 vote up vote down
FCTS ProjectMiscMar 25, 2001Status0 vote up vote down
Heart rate sensorMedicalOct 06, 2006Status-2 vote up vote down
Motor walker circuitModelsNov 16, 2002Status0 vote up vote down
Zener-based solar engineSolarNov 16, 2002Status0 vote up vote down
Morse Code Beacon KeyerRFSep 21, 2006Status-1 vote up vote down
PC Automatic Power-on CircuitPCMay 19, 2015Status-1 vote up vote down
Constant Temperature CircuitControlSep 21, 2006Status-1 vote up vote down
Improved FM Stereo ModulatorRFJul 09, 2002Status0 vote up vote down
Count Accumulator for Radiation Levels (CARL)MiscSep 21, 2006Status0 vote up vote down
Modifications for CDV700 Geiger CounterMiscSep 21, 2006Status0 vote up vote down
40-30 CW Transmitter (Tube based)TubeMay 19, 2015Status0 vote up vote down
The WB0RIO 6U8A Code Practice OscillatorTubeMay 19, 2015Status0 vote up vote down
The House Finch Direct Conversion Tube ReceiverTubeMay 19, 2015Status-1 vote up vote down
The Little Chickadee 6U8A QRP TransmitterTubeMay 19, 2015Status0 vote up vote down
Magic Eye Tube WavemeterTubeMay 19, 2015Status-1 vote up vote down
WB0RIO Piglet 6U8A Regenerative Receiver (Tube based)TubeMay 19, 2015Status0 vote up vote down
QRP Antenna TunerRFSep 21, 2006Status0 vote up vote down
All-Ears QSK Timing GeneratorTimingMay 19, 2015Status-1 vote up vote down
Smooth Tone Clickless CW Sidetone GeneratorRFSep 21, 2006Status0 vote up vote down
Power Supply for Vacuum Tube ExperimentsTubeMay 19, 2015Status0 vote up vote down
Regulated 12V Dual LED LampLEDMay 19, 2015Status1 vote up vote down
Regulated Dual 3 Watt White LED LampLEDMay 18, 2015Status0 vote up vote down
Regulated 24 Watt Broad Spectrum LED LampLEDMay 19, 2015Status0 vote up vote down
Lightning activated camera shutter triggerPhotoAug 17, 2009Status-1 vote up vote down
TTL Pulse Reading Logic ProbeTestSep 21, 2006Status0 vote up vote down
High Fidelity FM Stereo Modulator (Rev E2)RFMay 19, 2015Status0 vote up vote down
VXO FM BugTransmittersMay 19, 2015Status0 vote up vote down
Big Ear Stereo Parabolic MicrophoneMiscSep 21, 2006Status0 vote up vote down
Ultra Low Power LCD IndicatorMiscSep 21, 2006Status0 vote up vote down
13 Color LED Rainbow circuit schematicLEDSep 21, 2006Status-1 vote up vote down
Nine Volt Battery EliminatorPowerSep 07, 2009Status1 vote up vote down
Arduino LFO Waveform Generator V2ArduinoMay 19, 2015Status-1 vote up vote down
Vacuum Tube B+ Delay CircuitTubeMay 19, 2015Status0 vote up vote down
Hammonator Organ to Guitar Amp Conversion (tube amplifier)TubeSep 07, 2009Status-2 vote up vote down
Lil' Tiger Hammond AO-43 Organ to Guitar Amp ConversionMusicMay 19, 2015Status0 vote up vote down
Liquidator Tube Phaser/Chorus EffectTubeSep 07, 2009Status1 vote up vote down
Voltage Controlled PannerAudioSep 21, 2006Status-1 vote up vote down
Guitar Reverb Effect Version 2AudioSep 21, 2006Status-1 vote up vote down
Stereo Audio IsolatorAudioSep 21, 2006Status-1 vote up vote down
Panner Waveform GeneratorAudioSep 21, 2006Status-1 vote up vote down
Voltage controlled audio pannerAudioAug 01, 2010Status-1 vote up vote down
Isolated Telephone Interface (phone tap) for tape recorder, PC sound card etcTelephoneSep 21, 2006Status-1 vote up vote down
PWM DC Motor Speed ControlPowerSep 21, 2006Status0 vote up vote down
PWM Motor Speed Controller / DC Light DimmerControlSep 07, 2009Status2 vote up vote down
PWM Motor/Light Controller circuit diagramsControlSep 07, 2009Status-1 vote up vote down
Microprocessor RS-232 ResetMicrocontrollerSep 21, 2006Status0 vote up vote down
18 LED dimmable LED lamp circuit diagramLEDSep 07, 2009Status0 vote up vote down
Regulated Dual White LED LampLEDSep 07, 2009Status0 vote up vote down
Seven Component Regulated LED LampLEDSep 21, 2006Status0 vote up vote down
Buck Mode Switching Regulator for Solar ApplicationsSolarSep 21, 2006Status0 vote up vote down
12 Volt Battery Voltage Monitor (kit available)PowerJun 18, 2015Status1 vote up vote down
Solar Panel Charge Controller / Low Voltage Disconnect CircuitSolarJul 12, 2001Status-1 vote up vote down
Solar Panel Charge Controller / Low Voltage Disconnect Circuit (SPC1)SolarSep 07, 2009Status-1 vote up vote down
12 Volt 10 Amp Dark Activated Switch (kit available)ControlJun 18, 2015Status-1 vote up vote down
DAS1 - 12 Volt 10 Amp Dark Activated SwitchControlSep 07, 2009Status-1 vote up vote down
High Efficiency 12V White LED DriverLEDSep 21, 2006Status0 vote up vote down
12 Volt Differential Temperature ControllerControlSep 07, 2009Status-1 vote up vote down
Solar Panel Current MeterSolarJul 12, 2001Status0 vote up vote down
LED Mood LightLEDJul 12, 2001Status0 vote up vote down
Battery Low Voltage BeeperPowerSep 21, 2006Status0 vote up vote down
12 Volt 15 Amp Low Voltage Disconnect (kit available)PowerJun 18, 2015Status-1 vote up vote down
Remote Solar LED lightSolarSep 21, 2006Status-1 vote up vote down
PWM Motor Speed Controller / DC Light DimmerControlNov 17, 2002Status-1 vote up vote down
PWM Motor Speed Controller / DC Light DimmerPowerJul 12, 2001Status0 vote up vote down
PWM Motor/Light ControllerPowerJul 12, 2001Status-1 vote up vote down
SCC2 10 Amp Solar Charge ControllerSolarOct 30, 2002Status1 vote up vote down
SCC2 10 Amp Solar Charge ControllerSolarSep 07, 2009Status1 vote up vote down
12 Volt 20 Amp Solar Charge Controller (kit available)SolarJun 18, 2015Status0 vote up vote down
12 Volt 20 Amp Solar Charge ControllerSolarSep 21, 2006Status-1 vote up vote down
Shunt-mode Solar/Wind Charge ControllerSolarSep 07, 2009Status1 vote up vote down
Solar Powered Night LightSolarSep 07, 2009Status0 vote up vote down
Solar Charged LED FlashlightSolarJul 12, 2001Status0 vote up vote down
Self Powered Solar Box FurnaceSolarSep 21, 2006Status-1 vote up vote down
SPC2 6 Amp Solar Power CenterSolarSep 21, 2006Status1 vote up vote down
9 Amp in / 10 Amp out Solar Power Center (kit available)SolarJun 18, 2015Status1 vote up vote down
SPC3 9 Amp in / 10 Amp out Solar Power CenterSolarSep 07, 2009Status1 vote up vote down
Solar Powered Reading LampSolarSep 21, 2006Status-2 vote up vote down
12 Volt Toilet Tank Refiller circuit diagramMiscSep 21, 2006Status0 vote up vote down
Low Power LED VoltmeterPowerJul 12, 2001Status1 vote up vote down
WGR1 - 12 Volt Wind Generator RegulatorPowerMay 19, 2015Status0 vote up vote down
Expanded Scale Battery Volt MeterPowerSep 07, 2009Status0 vote up vote down
Stereo Test Tone GeneratorTestSep 21, 2006Status0 vote up vote down
Octopus Curve TracerTestMay 19, 2015Status-1 vote up vote down
Temperature Controlled Nicad ChargerPowerSep 21, 2006Status-1 vote up vote down
12V, 4-AA Cell Differential Temperature ChargerPowerAug 17, 2009Status0 vote up vote down
Motorized Video Camera MountVideoSep 21, 2006Status-2 vote up vote down
Morse Code Beacon KeyerMiscJan 26, 2001Status0 vote up vote down
Constant Temperature CircuitControlJan 26, 2001Status-1 vote up vote down
Lightning Activated Camera Shutter TriggerPhotoJan 26, 2001Status0 vote up vote down
Pulse Reading Logic ProbeTestJan 26, 2001Status0 vote up vote down
Micro Power FM Broadcasting CircuitsTransmittersJan 26, 2001Status0 vote up vote down
Voltage Controlled PannerAudioJan 26, 2001Status0 vote up vote down
PWM DC Motor Speed ControlControlJan 26, 2001Status-1 vote up vote down
Guitar Reverb PedalMusicJan 26, 2001Status0 vote up vote down
AA battery solar chargerSolarJan 26, 2001Status0 vote up vote down
Solar Panel Charge Controller / Low Voltage Disconnect CircuitSolarJan 26, 2001Status0 vote up vote down
Solar Panel Current MeterSolarJan 26, 2001Status0 vote up vote down
LED Mood LightLightingJan 26, 2001Status0 vote up vote down
PWM Motor/Light ControllerPowerJan 26, 2001Status0 vote up vote down
PWM Motor/Light Controller variantsPowerJan 26, 2001Status-1 vote up vote down
Low Power LED VoltmeterPowerJan 26, 2001Status0 vote up vote down
Temperature Controlled NICD ChargerPowerJan 26, 2001Status0 vote up vote down
Circuit for interfacing a relay / solenoid to a PC based on a 2N7000 FETPCSep 01, 2009Status-1 vote up vote down
Variety of receiver converter projectsRFApr 24, 2001Status0 vote up vote down
One transistor FM receiverRFApr 24, 2001Status-1 vote up vote down
42 Mc Band to 88 Mc Band (retrofit converter) ProjectRFApr 24, 2001Status-1 vote up vote down
RF noise bridge for HFRF Status-1 vote up vote down
LC meter with LCD display for readoutTest Status0 vote up vote down
160m mini portable End Fed Half Wave Tuner - MkIIRF Status0 vote up vote down
RF/SS Handie Hopper Transmitter SchematicTransmittersOct 23, 2002Status0 vote up vote down
AT90S8515 experimenter boardMicrocontrollerNov 27, 2002Status0 vote up vote down
DIY shutterglasses controllerGamesJan 26, 2001Status0 vote up vote down
Stop Action 3D-Photography using an audio flash triggerPhoto Status0 vote up vote down
Remote control uses an IR receiver chip to receive the IR signal from the remoteIR Status0 vote up vote down
How to construct Garmin GPS receiver interface cablesPCMar 23, 2003Status-1 vote up vote down
Vacuum Tube Microphone PreampTubeNov 01, 2002Status0 vote up vote down
FCD (Fuel Cut Defencer)AutomotiveOct 30, 2002Status0 vote up vote down
Jasmin floppy disk controller schematicsPCSep 13, 2006Status-2 vote up vote down
Weather station with pressure reading, relative humidity, indoor & remote temperature readingMisc Status0 vote up vote down
Battery Charger IdeasPowerAug 14, 2002Status0 vote up vote down
Crystal radio circuits including diode performance comparisonRFMar 10, 2003Status-1 vote up vote down
Game Show TimersGamesOct 06, 2006Status0 vote up vote down
Induction receiver for tracing wiring behind walls, hearing lightning and other electric dischargesMisc Status0 vote up vote down
Refrigerator Door AlarmAlarms Status-1 vote up vote down
Rain alarm / rain detectorAlarms Status-1 vote up vote down
Homebuilt video digitizer Mark IVideoFeb 01, 2003Status-1 vote up vote down
Homebuilt video digitizer Mark IIVideoFeb 01, 2003Status2 vote up vote down
Daisy MP3 player projectMusic Status0 vote up vote down
Simple open source MP3 player with SD/MMC memory card supportMusicMay 30, 2007Status0 vote up vote down
Archery timerGamesAug 14, 2002Status0 vote up vote down
Windmill DIY Analog MPPT (maximum power point tracker) CircuitPowerMar 09, 2012Status0 vote up vote down
CO2 controller for planted tanksControlJan 26, 2001Status0 vote up vote down
Ultrasonic Distance Measurement With the MSP430 (PDF)Microcontroller Status2 vote up vote down
Texas Instruments collection of differential op-amp circuits (PDF)Misc Status1 vote up vote down
Texas Instruments collection of buffer op-amp circuits for ADCMisc Status1 vote up vote down
Simple MPPT-Based (maximum power point tracker) Lead Acid Charger Using bq2031 (pdf)SolarMar 09, 2012Status-3 vote up vote down
Wireless local network for PalmPilot (large PDF)PDANov 16, 2002Status0 vote up vote down
FET Preamp CablePreampNov 01, 2002Status-3 vote up vote down
Building a Hardware Random Bit GeneratorMisc Status0 vote up vote down
Monostable multivibratorTimingJan 01, 2003Status0 vote up vote down
Altec 1564A Preamp Power SupplyPreampSep 13, 2006Status3 vote up vote down
Neumann U67 microphone preamp power supplyPreampSep 13, 2006Status-2 vote up vote down
Midibox 64MusicAug 09, 2002Status0 vote up vote down
TTL to RS232 adapter using 2N3906 / 2N3904 transistorsMicrocontroller Status0 vote up vote down
VK5JST Aerial analyserRFJun 24, 2015Status-1 vote up vote down
An Ultra Low Distortion Audio Test OscillatorAudioJun 24, 2015Status-1 vote up vote down
A dummy load and power meter for HF (PDF)RFJun 24, 2015Status0 vote up vote down
An ESR Meter For Electrolytic Capacitors (and Low Ohms Meter)TestJun 24, 2015Status-2 vote up vote down
20 amp (peak) power supply for SSB transceiversPowerJun 24, 2015Status0 vote up vote down
Build your own Q Meter projectTestJun 24, 2015Status1 vote up vote down
A Simple RF Probe For Your DVMTestJun 24, 2015Status1 vote up vote down
An RF Voltmeter for Transceiver ServicingTestJun 24, 2015Status-1 vote up vote down
Medium and Very High Quality Two Tone Generators for Transceiver TestingTestJun 24, 2015Status-1 vote up vote down
Highly sensitive and selective Field Strength Meter systemTestApr 14, 2011Status0 vote up vote down
Wide dynamic range Field Strength Meter mark ITestApr 14, 2011Status0 vote up vote down
Wide dynamic range Field Strength Meter mark IITestApr 14, 2011Status0 vote up vote down
RS232 - Lowe HF-225 interfacePCNov 21, 2002Status-1 vote up vote down
Addressable ADCData AcquisitionJul 24, 2002Status-1 vote up vote down
Battery CharacterizerPowerJul 24, 2002Status1 vote up vote down
Delayed shutter control for Kodak DC-20MiscJul 24, 2002Status0 vote up vote down
Combination Lock (PIC16F84)AlarmsJul 24, 2002Status-2 vote up vote down
PIC16F876 DataloggerMicrocontrollerJul 24, 2002Status2 vote up vote down
R/C Emergency locator alarmModelsJul 24, 2002Status0 vote up vote down
Combination lock for car liftgateAutomotiveJul 24, 2002Status-1 vote up vote down
Morse code displayMiscJul 24, 2002Status-2 vote up vote down
Kodak DC-20 camera interface (PIC12C509)PhotoJul 24, 2002Status-1 vote up vote down
Kodak DC-20 camera interface (PIC16F84)PhotoJul 24, 2002Status0 vote up vote down
Angelfire rocket GPS payloadModelsSep 10, 2006Status0 vote up vote down
Relay circuit for relay control via an RS232 portControl Status-1 vote up vote down
Serial to parallel converter - connect a large number of digital outputs to a PC parallel portPC Status-1 vote up vote down
Micro-step driver - connect a bipolar steppe motor to a PC through the parallel portControl Status0 vote up vote down
PC parallel port eight DC power switch cam driver two unipolar stepper motors, lights etcPC Status-1 vote up vote down
80 Metre CW beacon / transmitter circuit diagramTransmittersSep 01, 2009Status0 vote up vote down
ADXL202 break-out boardData Acquisition Status0 vote up vote down
Wisp628 ISP Microchip PIC ProgrammerProgrammersAug 09, 2002Status0 vote up vote down
WLoader - PIC16F877 application loader / bootloaderMicrocontrollerMay 01, 2004Status0 vote up vote down
Lead/acid battery chargerPower Status0 vote up vote down
Simple RIT circuit based on a 2N7000 FETRFSep 01, 2009Status-1 vote up vote down
Circuit for temperature stabilization of a MTP3055E MOSFETMiscSep 01, 2009Status0 vote up vote down
Digital signal processor (DSP) for radio communicationsFilterJun 06, 2003Status0 vote up vote down
Simple LED Constant Current Lighting CircuitLEDJul 11, 2012Status-1 vote up vote down
56K RF Modem circuit diagramRFJan 06, 2002Status-1 vote up vote down
29.85 MHZ bandpass filter schematicFilterNov 01, 2002Status1 vote up vote down
29.85 MHZ notch filter schematicFilterNov 01, 2002Status0 vote up vote down
Altec 428B Microphone Preamplifier schematicPreampSep 13, 2006Status0 vote up vote down
API 321 mic preamp schematicPreampSep 13, 2006Status2 vote up vote down
RCA BA-1A two-stage preamp schematicPreampSep 13, 2006Status0 vote up vote down
RCA BA-21A preamplifier schematicPreampSep 13, 2006Status0 vote up vote down
RCA BA-31A preamplifier schematicPreampSep 13, 2006Status3 vote up vote down
Poor man's analog to digital converter (ADC) using a 2N222 transistor and a few passives (PDF)Microcontroller Status-2 vote up vote down
GPS-based universal clock generatorTiming Status0 vote up vote down
Pic-Plot GPIB to RS-232 converterPC Status1 vote up vote down
Kenwood TH-D7 NMEA GPS bug fixMisc Status-1 vote up vote down
5 tubes SSB QRP Transceiver for 20m Ham bandTube Status1 vote up vote down
Pic-Plot2 GPIB to USB converterPC Status0 vote up vote down
Nixie clock (PIC16F876)TubeJun 18, 2003Status0 vote up vote down
Homemade scope clock using a DG7 tube and a Microchip PIC16F876Tube Status0 vote up vote down
ADC logger 6ch Measurent and serial port logger with wireless longrange linkData Acquisition Status0 vote up vote down
Atmel Mega32 8ch Analog signal measure loggerData Acquisition Status0 vote up vote down
Atmel Mega88 Dual Temperatur meterMicrocontroller Status0 vote up vote down
Atmel Mega88 Temperatur meter, Type K sensor, Heat set and regulatorMicrocontroller Status-1 vote up vote down
PA fan temperature controlled speed motor speed controllerControl Status-2 vote up vote down
PIC16 DemoKit3 with programmer and displaysProgrammers Status0 vote up vote down
144.000 Mhz CW TransmitterTransmitters Status-2 vote up vote down
2m (144MHz) Dual Gate FET Low Noise AmplifierRF_Amplifier Status-1 vote up vote down
Car Timer with Atmel ATiny45 to automatically turn of accessories to prevent flat batteryAutomotive Status-4 vote up vote down
VCO covers 300MHz to 500MHz based on Maxim MAX2608 VCOTiming Status0 vote up vote down
Digital Wattmeter, measures from nanowatts to kilowatts using AD8307, PIC16F876, LCD DisplayTest Status0 vote up vote down
200 Watt Modified PC Power Supply 13.5 Volt 14 AmpPowerJul 24, 2002Status-1 vote up vote down
SWR Bridge 1 to 1000 Mhz (1GHz)Test Status-1 vote up vote down
Homemade Water Drain Pump controllerControl Status-1 vote up vote down
Universal Exposure Timer and Event CounterPhoto Status1 vote up vote down
Computer Sound Port Shutter TesterPhotoAug 17, 2009Status0 vote up vote down
Field strength meter for the 137 kHz bandTestMay 01, 2004Status0 vote up vote down
Five Tube Stereo AmplifierTubeSep 13, 2006Status-1 vote up vote down
Dual stepper motor drivers using UDN2540ControlJul 03, 2011Status-1 vote up vote down
PWM DC motor driver and control with SG3525ControlJul 03, 2011Status-2 vote up vote down
Kenwood TR-7950 manual & schematics (PDF)RFSep 10, 2006Status0 vote up vote down
Battery Meter for Pinball MachinesGames Status0 vote up vote down
Novel BuzzerAlarmsNov 27, 2002Status-1 vote up vote down
Modular Burglar AlarmAlarmsNov 27, 2002Status-2 vote up vote down
Motorcycle alarmAlarmsNov 17, 2002Status0 vote up vote down
Enhanced 5 Digit Alarm KeypadAlarmsNov 27, 2002Status-2 vote up vote down
Enhanced 4 Digit Alarm KeypadAlarmsNov 27, 2002Status-1 vote up vote down
RF AlarmAlarmsNov 27, 2002Status-1 vote up vote down
Single Zone AlarmAlarmsNov 27, 2002Status-1 vote up vote down
Water Activated AlarmAlarmsNov 27, 2002Status1 vote up vote down
Water level alarmAlarmsNov 17, 2002Status-1 vote up vote down
2W Audio Amplifier using BD139 and BD140 transistorsAmplifiersJan 26, 2001Status2 vote up vote down
3-Band audio graphic equalizerAudioJan 26, 2001Status-2 vote up vote down
6-Input mixer circuit diagramAudioJan 26, 2001Status-1 vote up vote down
Doorphone intercomAudioJan 26, 2001Status0 vote up vote down
Hi Fi preampPreampJan 26, 2001Status-3 vote up vote down
Stereo audio line driver for running audio over long distance cablesAudioJan 26, 2001Status-1 vote up vote down
Variable notch filter with both high and low pass filtersFilterSep 13, 2006Status0 vote up vote down
Peak reading audio level meter using CA3140 opampAmplifiersJan 26, 2001Status-3 vote up vote down
Tone control circuit schematicAudioJan 26, 2001Status-2 vote up vote down
TDA2030 8 Watt amplifierAmplifiersJan 26, 2001Status-8 vote up vote down
Infra Red SwitchIRNov 27, 2002Status0 vote up vote down
IR remote control extenderIRJan 26, 2001Status0 vote up vote down
IR Remote Control Extender Circuit (Mark 2)IRNov 27, 2002Status0 vote up vote down
IR Remote Control Extender Circuit (Mark 3)IRNov 27, 2002Status1 vote up vote down
Infra Red wired Repeater circuit to control appliances from a remote locationIR Status0 vote up vote down
IR LinkIRNov 27, 2002Status0 vote up vote down
Multi Rocket LauncherModelsNov 27, 2002Status0 vote up vote down
Model rocket launch controllerModelsNov 27, 2002Status-1 vote up vote down
Doorbell for the deaf that provides a delayed visual indication when a doorbell switch is pressedMiscNov 27, 2002Status0 vote up vote down
Electromagnetic field detectorMiscJan 26, 2001Status1 vote up vote down
Hot Water Tank Level IndicatorControlNov 27, 2002Status-1 vote up vote down
High Quality IntercomMiscNov 27, 2002Status-1 vote up vote down
Basic infrared link for audio communication over distances up to 3 metresIRFeb 05, 2010Status-1 vote up vote down
Magnetic Gun.MiscNov 27, 2002Status0 vote up vote down
Single chip metal detecor with a range of a few inches based on CS209AMetal Status2 vote up vote down
Perimeter monitorAlarmsJan 26, 2001Status-1 vote up vote down
Quiz game circuitGamesNov 27, 2002Status0 vote up vote down
Speaker Microphone CircuitAudioNov 27, 2002Status-1 vote up vote down
Static Electricity / Negative Ion DetectorMiscNov 27, 2002Status0 vote up vote down
Temperature monitor using 741 opampControlJan 26, 2001Status-1 vote up vote down
Ultrasonic dog whistleMiscJan 26, 2001Status0 vote up vote down
Electronic canary sound effectsAudioJan 26, 2001Status-2 vote up vote down
Electronic sirenAudioNov 27, 2002Status0 vote up vote down
Sound Effects GeneratorMusicNov 27, 2002Status1 vote up vote down
Sound Effects Generator 2MusicNov 27, 2002Status-3 vote up vote down
12V 30A power supply circuit diagramPowerJan 26, 2001Status-1 vote up vote down
Dual regulated power supplyPowerJan 26, 2001Status-2 vote up vote down
Fuse blown indicatorPowerJan 26, 2001Status1 vote up vote down
Gyrator circuitPowerJan 26, 2001Status0 vote up vote down
LM317 Regulator CircuitPowerNov 27, 2002Status-2 vote up vote down
Nicad battery chargerPowerJan 26, 2001Status0 vote up vote down
Unregulated power supplyPowerJan 26, 2001Status0 vote up vote down
Camera switching circuit to run multiple cameras with one monitorVideo Status0 vote up vote down
Cold activated switch (frost alarm)AlarmsJan 26, 2001Status-1 vote up vote down
Voltage comparator switchControlJan 26, 2001Status-1 vote up vote down
Dark activated switchControlJan 26, 2001Status0 vote up vote down
Push Button Switch DebouncerTimingJan 26, 2001Status0 vote up vote down
Digital combination lock circuit diagramAlarmsJan 26, 2001Status-1 vote up vote down
Alarm control keypadAlarmsNov 27, 2002Status-1 vote up vote down
Light detectorControlJan 26, 2001Status1 vote up vote down
Electronic night lightLightingJan 26, 2001Status-2 vote up vote down
DC Motor Reversing CircuitControlNov 27, 2002Status0 vote up vote down
Sound operated switchControlJan 26, 2001Status0 vote up vote down
Multi wire cable tester that handles up to eight conductorsTestNov 27, 2002Status0 vote up vote down
Connection tester for checking solder joints and other connectionsTestNov 27, 2002Status0 vote up vote down
EMF field probe (electromagnetic field probe) covering up to 100kHzTestJan 26, 2001Status0 vote up vote down
Function generator based on 8038PCD function generator ICTestJan 26, 2001Status0 vote up vote down
IR remote control testerIRJan 26, 2001Status0 vote up vote down
Zener diode tester based on a 555 timerTestJan 26, 2001Status1 vote up vote down
5 to 30 Minute Timer circuit diagramTimingNov 27, 2002Status1 vote up vote down
NE555 Basic MonostableTimingNov 27, 2002Status0 vote up vote down
Commodore 64 Video Modulator 251025 SchematicsVideoNov 16, 2002Status0 vote up vote down
Commodore 64 Video Modulator 251696 SchematicsVideoNov 16, 2002Status6 vote up vote down
Computerized Infrared RemoteIRAug 27, 2003Status0 vote up vote down
Darkroom timer using PIC16F84AMicrocontrollerMar 07, 2009Status0 vote up vote down
Lego Mindstoms IR Link PIC transceiverGamesMar 07, 2009Status-1 vote up vote down
Lego Mindstorms Double Rotation SensorGamesMar 07, 2009Status0 vote up vote down
LC filter design on-line calculatorFilterJun 13, 2002Status0 vote up vote down
Envelope generator ADSRAudio Status-2 vote up vote down
Scaling ADXL50 accelerometer outputMiscJan 26, 2001Status-1 vote up vote down
Wireless Electrocardiogram MonitorMedicalOct 06, 2006Status0 vote up vote down
Beat Tracking StrobeAudio Status0 vote up vote down
Sniper tag laser beam detectorLaserOct 06, 2006Status0 vote up vote down
Galvanic Skin Response (GSR) CircuitMedical Status1 vote up vote down
Accurate Digital LC Meter based on a PIC16F84TestFeb 20, 2013Status0 vote up vote down
Simple high current pulsed laser driver using an avalanche transistorLaser Status0 vote up vote down
Common Ground for Older VPW OBD CircuitAutomotiveMay 01, 2004Status-1 vote up vote down
USB to parallel port converter using Cypress CY7C68013A-56PVXCPC Status0 vote up vote down
Mini dice - PIC10F200-based electronic diceMicrocontrollerJun 28, 2015Status2 vote up vote down
5V solar power supplySolarJun 28, 2015Status0 vote up vote down
Tic tac toe game based on a PIC16F628GamesJun 28, 2015Status-2 vote up vote down
2A power supply - An adjustable power supply for model railways and general projectsPowerJun 28, 2015Status-1 vote up vote down
A handy 2-Input alarm using the PIC Lick-1 moduleAlarmsJun 28, 2015Status-1 vote up vote down
4 channel RF remote controlControlJun 28, 2015Status1 vote up vote down
Infrasound circuits including several infrasound amplifier circuit diagramsMiscJul 05, 2015Status0 vote up vote down
Collection of eight audio amplifier circuit diagramsAmplifiersJul 05, 2015Status-5 vote up vote down
Clock project based on National Semincondutor MM5402NTimingJul 05, 2015Status0 vote up vote down
Bug Duster - a detector for uncovering RF-based video and audio bugging devicesRFJul 10, 2015Status-1 vote up vote down
Ghost detector - detects if a ghost disturbs the electric field in the vicinity of the deviceMiscJul 10, 2015Status0 vote up vote down
Lightning detector to receive static pulses from lightning at a frequency near 200 kHzMiscJul 10, 2015Status0 vote up vote down
Low Frequency Block Converter - Converts VLF/LF bands to shortwave frequenciesRFJul 10, 2015Status0 vote up vote down
Computer datalogger circuitsData AcquisitionJul 10, 2015Status0 vote up vote down
Simple Computer A/D Uses a Serial PortData AcquisitionJul 10, 2015Status0 vote up vote down
24 Line Parallel Interface for the PC - old ISA based design (PDF)PCJul 10, 2015Status0 vote up vote down
Active antenna that will work from below a few kHz to over 100 MHzRFJul 10, 2015Status0 vote up vote down
Atmospheric receiver to detect crackling static in a radio produced by lightningMiscJul 10, 2015Status-1 vote up vote down
CW transmitter for 80 m and 40 m amateur radio bands based on AD9833 DDSTransmittersJul 13, 2015Status0 vote up vote down
All-Digital Stereo FM Transmitter with RDS based on AD9852 DDS (PDF)TransmittersJul 13, 2015Status1 vote up vote down
FM transmitter based on MC145170 PLL and Mini-circuits POS150TransmittersJul 13, 2015Status0 vote up vote down
SWR protection board for 20W Mosfet FM amplifierRF_AmplifierJul 13, 2015Status2 vote up vote down
25W FM MOSFET RF power amplifier based on BLF245RF_AmplifierJul 13, 2015Status4 vote up vote down
100W FM RF power amplifier based on MRF317RF_AmplifierJul 13, 2015Status-2 vote up vote down
5W PLL FM Transmitter with typical output power of 5 W and no-tune designTransmittersJul 13, 2015Status0 vote up vote down
Programmable PLL (Si570) Local Oscillator for HF Receivers, Transmitters, Transceivers (PDF)RFJul 13, 2015Status-2 vote up vote down
Mini AM transmitter using LM386 and 4 MPF102 FETs for an output stageTransmittersJul 13, 2015Status0 vote up vote down
50W linear amplifier for 40 and 80 meter band using IRFP150 MOSFETsRF_AmplifierJul 13, 2015Status2 vote up vote down
All-purpose 0 - 30 MHz DDS VFO and Signal Generator based on the article by WB2V in QEX July, 1997.RFJul 13, 2015Status0 vote up vote down
DDS based Signal Generator that runs from 1Hz to 60MHz in 1Hz stepsRFJul 13, 2015Status0 vote up vote down
Standalone Multiband WSPR beacon transmitter (MEPT) - PDF fileTransmittersJul 13, 2015Status0 vote up vote down
Simpler temperature datalogger based on PIC12F683 and Maxim DS18B20Data AcquisitionJul 15, 2015Status1 vote up vote down
Gym Agility: A Simple Strategy Game using a 4067 multiplexer and 4093 Schmitt NAND gateGamesJul 15, 2015Status-1 vote up vote down
Anti-Theft Security For Car Audios based on a CMOS NAND chip CD4093AlarmsJul 15, 2015Status-1 vote up vote down
Luggage Security System based on UM3561 melody generator ICAlarmsJul 15, 2015Status0 vote up vote down
Powerful buzzer for use as a doorbell or to notify others in different rooms dinner is ready etcMiscJul 15, 2015Status0 vote up vote down
Infrared Proximity Detector AlarmIRJul 15, 2015Status0 vote up vote down
General purpose alarm using discrete transistorsAlarmsJul 15, 2015Status-1 vote up vote down
Simple Darkness Activated Alarm using a 555 timerAlarmsJul 15, 2015Status-1 vote up vote down
Model Railway Short-Circuit BeeperModelsJul 15, 2015Status0 vote up vote down
Circuit diagram for a simple, gated, pulsed alarmAlarmsJul 15, 2015Status-1 vote up vote down
Simple laser alarm that gets triggered when beam from a laser pointer is brokenLaserJul 15, 2015Status0 vote up vote down
Speed Alarm For CarsAutomotiveJul 15, 2015Status3 vote up vote down
Remote Alarm For Smoke DetectorAlarmsJul 15, 2015Status-1 vote up vote down
Simple 6-Input Alarm that was designed for use in a combined garage and rumpus roomAlarmsJul 15, 2015Status-1 vote up vote down
Night Alert that turns a light on for a short time when a dog is barking to scare off intrudersAlarmsJul 15, 2015Status0 vote up vote down
Simple Knock Alarm With Piezo SensorAlarmsJul 15, 2015Status0 vote up vote down
Smoke Alarm Battery Life ExtenderAlarmsJul 15, 2015Status-1 vote up vote down
Mains Supply Failure AlarmAlarmsJul 15, 2015Status-1 vote up vote down
Water Alarm Circuit DiagramAlarmsJul 15, 2015Status-1 vote up vote down
Midnight Security Light Circuit SchematicAlarmsJul 15, 2015Status-1 vote up vote down
Low Cost Burglar Alarm For BoatsAlarmsJul 15, 2015Status-2 vote up vote down
Water Level Alert - 1.5V battery powered portable unitAlarmsJul 15, 2015Status0 vote up vote down
Two-Tone Siren Using One 4093 ICAudioJul 15, 2015Status0 vote up vote down
Fridge Door Alarm Circuit - Beeps if you leave open the door over 20 secondsAlarmsJul 15, 2015Status-1 vote up vote down
Broken Charger Connection Alarm CircuitPowerJul 15, 2015Status1 vote up vote down
Fire Alarm Using ThermistorAlarmsJul 15, 2015Status-1 vote up vote down
Safety Guard - Simple unit, Protects home appliances from voltage spikesPowerJul 15, 2015Status0 vote up vote down
Powerful Security Siren - Transistors based and operates from 12V power supplyMiscJul 15, 2015Status1 vote up vote down
Mini Alarm - Suitable for doors & windows, Portable anti-bag-snatching unitAlarmsJul 15, 2015Status-2 vote up vote down
Heart Rate Monitor based on a dual op-amp ICMedicalJul 22, 2015Status2 vote up vote down
Model Railway Turnout ControlModelsJul 22, 2015Status0 vote up vote down
Transcutaneous Electrical Nerve Stimulator (TENS)MedicalJul 22, 2015Status0 vote up vote down
Tablet Reminder That Uses Watch ModuleMedicalJul 22, 2015Status1 vote up vote down
LED dice based on a 4060 chipGamesJul 22, 2015Status1 vote up vote down
Cranial Electrotherapy Stimulator Circuit DiagramMedicalJul 22, 2015Status7 vote up vote down
Pulse Generator And Signal Tracer Circuit DiagramTestJul 22, 2015Status1 vote up vote down
Whistle Responder - Beeps when hears your whistle, A gadget suitable for key-holders, games etc.MiscJul 22, 2015Status0 vote up vote down
Sleeping aid circuit diagramMedicalJul 22, 2015Status-1 vote up vote down
Digital Step-Km Counter Circuit SchematicMedicalJul 22, 2015Status1 vote up vote down
Remote-Controlled Fan RegulatorControlJul 30, 2015Status0 vote up vote down
Laser-Guided Door OpenerLaserJul 30, 2015Status1 vote up vote down
Automatic Room Power ControlControlJul 30, 2015Status0 vote up vote down
Water Level Indicator Using 7-Segment DisplayMiscJul 30, 2015Status0 vote up vote down
Rainwater Storage GaugeMiscJul 30, 2015Status-1 vote up vote down
Cat and Dog RepellerMiscJul 30, 2015Status0 vote up vote down
Inexpensive Remote Watering SystemMiscJul 30, 2015Status0 vote up vote down
You Have Mail! Letterbox monitoring systemMiscJul 30, 2015Status-1 vote up vote down
Whistling KettleAudioJul 30, 2015Status-1 vote up vote down
Gentle breeze fan controllerControlJul 30, 2015Status0 vote up vote down
Automatic Range HoodControlJul 30, 2015Status-1 vote up vote down
Running 12V Fan Directly on 220V ACPowerJul 30, 2015Status1 vote up vote down
Environmentally-friendly Mosquito RepellerMiscJul 30, 2015Status0 vote up vote down
Doorbell Memory Circuit DiagramMiscJul 30, 2015Status-1 vote up vote down
Fridge-Door Open Alarm Circuit ProjectAlarmsJul 30, 2015Status-2 vote up vote down
Automatic Water Tank Filler Circuit DiagramControlJul 30, 2015Status0 vote up vote down
Digital Remote ThermometerData AcquisitionJul 30, 2015Status0 vote up vote down
Plant Watering Watcher Circuit SchematicMiscJul 30, 2015Status0 vote up vote down
Salt Taster Circuit DiagramMiscJul 30, 2015Status1 vote up vote down
Fridge Door Alarm Schematic 2nd VersionAlarmsJul 30, 2015Status1 vote up vote down
Room Noise Detector Circuit SchematicAudioJul 30, 2015Status-1 vote up vote down
Heating System Thermostat CircuitControlJul 30, 2015Status2 vote up vote down
The Curious C-Beeper - a probe beeps at a frequency that varies with capacitanceTestSep 03, 2015Status1 vote up vote down
DIY Digital AC Watt MeterTestSep 30, 2015Status-2 vote up vote down
Dual Relay Driver Board Circuit SchematicControlOct 06, 2015Status1 vote up vote down
Relative Field Strength Meter For A DMMTestOct 06, 2015Status1 vote up vote down
Logic Probe With SoundTestOct 06, 2015Status0 vote up vote down
430J Coil Gun circuit schematicMiscOct 13, 2015Status1 vote up vote down
Stun gun circuit diagram and construction detailsMiscOct 13, 2015Status0 vote up vote down
Negative ion generator circuit diagramMiscOct 13, 2015Status1 vote up vote down
Circuit diagram for simple DIY induction heaterMiscOct 13, 2015Status1 vote up vote down
ECG Amplifier using TLC274 opampMedicalOct 22, 2015Status0 vote up vote down
Railway Points SequencerModelsOct 22, 2015Status0 vote up vote down
Pulse rate monitor using TLC274 opampMedicalOct 22, 2015Status-1 vote up vote down
Pills reminder alarm using CMOS logic gatesMedicalOct 22, 2015Status3 vote up vote down
Quick Counter For Young Children - encourages children to countGamesOct 22, 2015Status0 vote up vote down
LED Noughts And CrossesLEDOct 22, 2015Status-2 vote up vote down
LED Chaser Provides Three Game FunctionsLEDOct 22, 2015Status1 vote up vote down
Low-Cost Dual Digital DiceLEDOct 22, 2015Status-1 vote up vote down
Soldering Iron Tip PreserverMiscOct 22, 2015Status-2 vote up vote down
Morse Code Beacon KeyerMiscNov 30, 2015Status0 vote up vote down
The WB0RIO 28 Mhz FSCW Beacon using an ArduinoArduinoNov 30, 2015Status-1 vote up vote down
FuzzniKator Push-Pull Tube Distortion/Preamp BoxTubeNov 30, 2015Status-1 vote up vote down
Voltmeter and Ammeter using PIC MicrocontrollerMicrocontrollerJan 14, 2016Status2 vote up vote down
PIC based digital voltmeter (DVM)MicrocontrollerJan 14, 2016Status-1 vote up vote down
Arduino 7 Segment LED Display and CounterArduinoApr 30, 2016Status-1 vote up vote down
Arduino alarm clock using 16x2 LCD moduleArduinoApr 30, 2016Status-1 vote up vote down
Smart NiMh battery charger based on Attiny85MicrocontrollerApr 30, 2016Status0 vote up vote down
Arduino based distance sensorArduinoApr 30, 2016Status-1 vote up vote down
DIY wattmeter with an ArduinoArduinoApr 30, 2016Status-1 vote up vote down
Realtime GPS+GPRS Tracking of Vehicles Using ArduinoArduinoApr 30, 2016Status-2 vote up vote down
PC-based heart rate monitor using Arduino and Easy Pulse sensorMedicalApr 30, 2016Status-1 vote up vote down
GSM Home Security Alarm System with ArduinoArduinoApr 30, 2016Status-1 vote up vote down
DIY intervalometer based on ArduinoPhotoApr 30, 2016Status-1 vote up vote down
Arduino based line following robot in 10 minutesArduinoApr 30, 2016Status1 vote up vote down
Arduino High speed Oscilloscope with PC interfaceArduinoApr 30, 2016Status-1 vote up vote down
Arduino LCD digital clock using a DS1307 RTCArduinoJun 28, 2016Status-1 vote up vote down
XBee ZNet 2.5 Wireless AccelerometerData AcquisitionJun 28, 2016Status0 vote up vote down
UHF amplifier for 400 ~ 850MHz using a 2SC3358 transisorRF_AmplifierJun 28, 2016Status-2 vote up vote down
HF 10W Power AmplifierRF_AmplifierJun 28, 2016Status-2 vote up vote down
144 MHz 125W Power AmplifierRF_AmplifierJun 28, 2016Status3 vote up vote down
High power mobile phone Jammer circuitTelephoneJun 28, 2016Status-3 vote up vote down
Arduino RF power meter that measures - 43 dBm to - 3 dBm, 1 MHz to 10 GHz using AD8319 and TMP101ArduinoJul 03, 2016Status-1 vote up vote down
DIY 4-Digit LED Digital Voltmeter Module based on ATmega8TestJul 03, 2016Status0 vote up vote down
Microphone preamplifier using an LM321 for interfacing an electret microphone to ArduinoArduinoJul 03, 2016Status-1 vote up vote down
TTL UART to RS232 level converter using ST232CDRPCJul 03, 2016Status0 vote up vote down
UART - USB Adapter using a MCP2200PCJul 03, 2016Status0 vote up vote down
UART - XPORT Adapter to allow embedded devices to be accessed from an Ethernet networkPCJul 03, 2016Status0 vote up vote down
USB - IR - Transceiver (aka Ghetto Blaster)IRJul 03, 2016Status0 vote up vote down
USB - PLL / DDS - InterfacePCJul 03, 2016Status0 vote up vote down
AD9833 Micro Waveform Generator for an ArduinoArduinoJul 03, 2016Status-1 vote up vote down
ARDUINO/Genuino 'Pocket Calculator' ShieldArduinoJul 03, 2016Status-1 vote up vote down
Countdown timer using an ArduinoArduinoJul 03, 2016Status0 vote up vote down
Arduino based environmental datalogger systemArduinoJul 03, 2016Status-1 vote up vote down
Arduino precision voltage reference based on a REF102 reference sourceArduinoJul 03, 2016Status-1 vote up vote down
Arduino shield to make a transistor curve tracerArduinoJul 03, 2016Status0 vote up vote down
Arduino Scalar Network Analyzer, 60 MHz, 80 dBArduinoJul 03, 2016Status-1 vote up vote down
DIY Dual Directional Coupler, 5 - 1000 MHz, 20 dBRFJul 03, 2016Status1 vote up vote down
High Voltage Power Supply step-up converter using a MC34063 ideal for a geiger counter or nixie tubeTubeJul 03, 2016Status0 vote up vote down
Low Voltage Power Supply / step down using a MC34063PowerJul 03, 2016Status1 vote up vote down
A small power supply for universal use based on an LM317 adjustable regulatorPowerJul 03, 2016Status1 vote up vote down
Linear regulated bench power supply 20V, 2A - easy to upgradePowerJul 03, 2016Status0 vote up vote down
Bench power supply with buck converter with a linear afterburnerPowerJul 03, 2016Status0 vote up vote down
Small 2.5 - 50V power supply for universal use based on a LT1074PowerJul 03, 2016Status1 vote up vote down
Linear Power Supply 8 .. 16 V ~ 10A that offers low noisePowerJul 03, 2016Status-1 vote up vote down
Artificial ground to transform an Unipolar Power Supply into a Bipolar Power SupplyPowerJul 03, 2016Status1 vote up vote down
Broadband UHF AmplifierRF_AmplifierJul 03, 2016Status-4 vote up vote down
A universal VCO Board using a MC100EL1648DG and a PGA-103+ as bufferRFJul 03, 2016Status-1 vote up vote down
A universal XCO/PLL Board that replaces crystal oscillator modulesTimingJul 03, 2016Status0 vote up vote down
MEMS oscillator evaluation board for SiT8008/SiT8208/SiT8209 from SiTimeTimingJul 03, 2016Status0 vote up vote down
Homebrew DDS Generator (with AD9851) V2.0TimingJul 03, 2016Status1 vote up vote down
Mini RF frequency synthesizer using an MC12095 and MC12080 or MB 501RFJul 03, 2016Status1 vote up vote down
10 kHz to10 GHz LED-Bargraph Power Meter - W1GHZRFJul 24, 2016Status3 vote up vote down
RF Power CalibratorTestJul 24, 2016Status0 vote up vote down
TDR Test System - WA0PIATestJul 24, 2016Status2 vote up vote down
Satellite FinderTestJul 24, 2016Status-3 vote up vote down
Lighting Storm MonitorMiscJul 24, 2016Status-1 vote up vote down
Simple Crystal Tester - F5JTZTestJul 24, 2016Status2 vote up vote down
Variable PIN Attenuator 1dB to 20dBRFSep 07, 2016Status0 vote up vote down
L-C-R Bridge - G3BIKTestSep 07, 2016Status0 vote up vote down
Microwave Motion DetectorAlarmsSep 07, 2016Status-1 vote up vote down
UHF Movement DetectorAlarmsSep 07, 2016Status-2 vote up vote down
UHF Doppler Motion DetectorAlarmsSep 07, 2016Status-2 vote up vote down
Metal Detector 1 MHzMetalSep 07, 2016Status2 vote up vote down
Metal Detector Simple BFOMetalSep 07, 2016Status1 vote up vote down
Ultrasonic Proximity DetectorAlarmsSep 07, 2016Status1 vote up vote down
Ultrasonic Radar Alarm CircuitAlarmsSep 07, 2016Status-1 vote up vote down
Power Supply 13.8V/20APowerSep 07, 2016Status0 vote up vote down
300 Hz - 3 kHz Microphone FilterFilterSep 07, 2016Status0 vote up vote down
Variable CW Bandpass FilterFilterSep 07, 2016Status0 vote up vote down
Dynamic Noise FilterFilterSep 07, 2016Status-1 vote up vote down
40dB Audio Notch FilterFilterSep 07, 2016Status0 vote up vote down
Headphone MOSFET AmplifierAmplifiersSep 07, 2016Status-1 vote up vote down
3.5W Low Distortion Audio Power AmplifierAmplifiersSep 07, 2016Status-3 vote up vote down
Perfect Sinus 1 kHz OscillatorTimingSep 07, 2016Status0 vote up vote down
Carbon Mike Preamp BPF - W6GXNPreampSep 07, 2016Status-2 vote up vote down
Microphone Preamp MC-80PreampSep 07, 2016Status3 vote up vote down
1MHz-step Harmonic Marker GeneratorTestSep 07, 2016Status1 vote up vote down
1 Hz to 10 MHz Voltage to Frequency ConverterMiscSep 07, 2016Status0 vote up vote down
Tunable Audio FilterFilterSep 07, 2016Status1 vote up vote down
Infrared Audio Transmitter-ReceiverIRSep 07, 2016Status2 vote up vote down
RF Activated Relay - W7ZOIRFSep 07, 2016Status0 vote up vote down
Wide Bandwidth Cell Phone JammerMiscSep 07, 2016Status-1 vote up vote down
800 MHz Base Station Chaos JammerMiscSep 07, 2016Status-1 vote up vote down
800 MHz Phone JammerMiscSep 07, 2016Status0 vote up vote down
1900 MHz Phone JammerMiscSep 07, 2016Status0 vote up vote down
GSM Phone Jammer - P2JBZMiscSep 07, 2016Status0 vote up vote down
Near-Field PCS Phone JammerMiscSep 07, 2016Status1 vote up vote down
PCS Phone JammerMiscSep 07, 2016Status-1 vote up vote down
Laser RX/TX AudioLaserSep 07, 2016Status0 vote up vote down
Device to monitor the power supply voltages of Commodore computers and warn if they are out of specPCMay 01, 2015Status-1 vote up vote down
Digital Logic Based LED Christmas Tree with 64 LEDs (constructed vertically from circuit board)LEDMay 01, 2015Status0 vote up vote down
Nixie-Clock using Neon Lamps to form Logic GatesTubeMay 01, 2015Status0 vote up vote down
555 based beeper signals when file finished loading from Commodore computer tape drivePCMay 01, 2015Status0 vote up vote down
Logic IC Tester with PC Parallel Port Interface - using 8255 Interface ICTestMay 01, 2015Status-1 vote up vote down
555 Based Switch for R/C receivers can be used without loss of R/C channelsModelsMay 01, 2015Status0 vote up vote down
Adapter to use Mega Drive / Genesis Controllers with a Vectrex Video Game ConsoleGamesMay 01, 2015Status0 vote up vote down
600 MHz to 2.2GHz VCOTimingSep 14, 2016Status0 vote up vote down
800 MHz to 2.2GHz Push-Pull VCOTimingSep 14, 2016Status0 vote up vote down
Audio/Video TransmitterVideoSep 14, 2016Status1 vote up vote down
AM TV TransmitterVideoSep 14, 2016Status1 vote up vote down
23cm ATV FM TransmitterVideoSep 14, 2016Status1 vote up vote down
A-V UHF TV ModulatorVideoSep 14, 2016Status2 vote up vote down
Crystal TV Video ModulatorVideoSep 14, 2016Status0 vote up vote down
TV Audio-Video TransmitterVideoSep 14, 2016Status1 vote up vote down
Simple TV Video ModulatorVideoSep 14, 2016Status0 vote up vote down
TV ModulatorVideoSep 14, 2016Status1 vote up vote down
1.3 GHz FMTV Receiver - ZL1WTTVideoSep 14, 2016Status0 vote up vote down
1.3 GHz ATV FM Transmitter - IZ3CTSVideoSep 14, 2016Status0 vote up vote down
10 GHz ATV Modulator Gunn-Diode - GW6BWXVideoSep 14, 2016Status1 vote up vote down
432 MHz to Ch2 ATV Converter - W9NTPVideoSep 14, 2016Status-1 vote up vote down
10 GHz Small ATV Transmitter - HB9SLVVideoSep 14, 2016Status1 vote up vote down
UHF 2W AM ATV TransmitterVideoSep 14, 2016Status0 vote up vote down
UHF 5W AM ATV TransmitterVideoSep 14, 2016Status1 vote up vote down
902 MHz PLL FM ATV TransmitterVideoSep 14, 2016Status-1 vote up vote down
Metal Detector Heathkit GD-1190MetalSep 14, 2016Status-2 vote up vote down
Metal Detector Heathkit GR-1290MetalSep 14, 2016Status2 vote up vote down
Gunn diode proximity detectorAlarmsSep 14, 2016Status-1 vote up vote down
Infrared Proiximity Detector using a CA3240AlarmsSep 14, 2016Status-3 vote up vote down
Thermal Proximity Detector using a RPW100AlarmsSep 14, 2016Status0 vote up vote down
AVR-PG1 - Serial port (RS232) PONY PROG compatible AVR programmerProgrammersSep 14, 2016Status0 vote up vote down
ISP Flash Microcontroller Programmer for 8051 and AVR series devicesProgrammersSep 14, 2016Status-2 vote up vote down
Arduino Flame Sensor InterfaceArduinoSep 14, 2016Status-1 vote up vote down
Electronic Stethescope Amplifier CircuitMedicalSep 14, 2016Status-1 vote up vote down
Open Source Optical Flash Trigger that Works with Any CameraPhotoSep 26, 2016Status0 vote up vote down
Build a Raspberry Pi-Based Cable Shutter Release for Sony CamerasPhotoSep 26, 2016Status0 vote up vote down
Collection of high-speed flash photography circuit diagramsPhotoSep 26, 2016Status0 vote up vote down
50 kHz to 70 MHz Spectrum Analyzer - K7TAUTestSep 28, 2016Status0 vote up vote down
Spectrum Analyzer on the OscilloscopeTestSep 28, 2016Status2 vote up vote down
0 to 60 MHz Spectrum Analyzer - WB5IPMTestSep 28, 2016Status-1 vote up vote down
Spectrum Analyzer using TV-Tuner - W6WTUTestSep 28, 2016Status1 vote up vote down
1 GHz Spectrum Analyzer Front-EndTestSep 28, 2016Status0 vote up vote down
100 MHz Spectrum Analyzer - W6URHTestSep 28, 2016Status-1 vote up vote down
0 - 100 MHz Spectrum Analyzer Tracking Generator - W6URHTestSep 28, 2016Status0 vote up vote down
Panoramic Spectrum Analyzer for HF Receivers - WA6NCXTestSep 28, 2016Status0 vote up vote down
TV Tuner Spectrum Analyzer - WA2PZOTestSep 28, 2016Status0 vote up vote down
20 MHz to 600 MHz Spectrum MonitorTestSep 28, 2016Status0 vote up vote down
IF for TV-Tuner for Spectrum Analyzers - AA4FBTestSep 28, 2016Status0 vote up vote down
200 MHz Spectrum AnalyzerTestSep 28, 2016Status3 vote up vote down
45 MHz to 2050 MHz Spectrum AnalyzerTestSep 28, 2016Status-3 vote up vote down
10 GHz Transceiver from a Radar Detector - WA5VJBRFSep 28, 2016Status0 vote up vote down
161 kHz Metal DetectorMetalSep 28, 2016Status0 vote up vote down
200 kHz Metal DetectorMetalSep 28, 2016Status1 vote up vote down
Baxandall Audio FilterFilterSep 28, 2016Status1 vote up vote down
Active Audio BPF 1kHz BandwidthFilterSep 28, 2016Status0 vote up vote down
CW Filter - DL7HGFilterSep 28, 2016Status-1 vote up vote down
Dynamic Mike Preamplifier for IC-706 - W5RKPreampSep 28, 2016Status-2 vote up vote down
Mike Preamplifier with Dynamic CompressorPreampSep 28, 2016Status-4 vote up vote down
Variable Audio Notch Filter - K4VIZFilterSep 28, 2016Status1 vote up vote down
Simple FET Audio FilterFilterSep 28, 2016Status0 vote up vote down
Two-Tone Audio Generator - M0DGQTimingSep 28, 2016Status0 vote up vote down
Microphone Preamplifier with Variable Gain LM358PreampSep 28, 2016Status-8 vote up vote down
Ipod Shuffle Usb Cable Wiring DiagramPDASep 28, 2016Status0 vote up vote down
Laser Diode ModulatorLaserOct 02, 2016Status1 vote up vote down
VOX circuit diagram (voice operated relay)AudioOct 02, 2016Status1 vote up vote down
RX/TX 27 MHz Wireless Remote ControlControlOct 02, 2016Status1 vote up vote down
3-Tones Controlled RelayControlOct 02, 2016Status0 vote up vote down
Once pulse per pushbutton press circuit diagramMiscOct 02, 2016Status0 vote up vote down
Wireless AM MicrophoneTransmittersOct 02, 2016Status0 vote up vote down
0.5W FM Transmitter 88MHz-108MHzTransmittersOct 02, 2016Status-1 vote up vote down
Laser-Torch Wireless CommunicationLaserOct 08, 2016Status0 vote up vote down
MOSFET Temperature ProtectionMiscOct 08, 2016Status0 vote up vote down
FM Laser Transceiver - VK7MULaserOct 08, 2016Status0 vote up vote down
Laser Detector - W4KAELaserOct 08, 2016Status1 vote up vote down
CW-PWM-AM Laser Transceiver - G0MRFLaserOct 08, 2016Status0 vote up vote down
Build a USB Powered AA NiMH and NiCd Battery ChargerPCOct 15, 2016Status0 vote up vote down
BattMan II: Build a Computer Controlled Battery ManagerPowerOct 15, 2016Status0 vote up vote down
Build a High Speed NiCd Charger for Electric R/CModelsOct 15, 2016Status0 vote up vote down
Build a Low Cost Thermal Peak Detection NiCd ChargerPowerOct 15, 2016Status-1 vote up vote down
Build a Miniature High-Rate Speed Control with Battery Eliminator Circuit (BEC)ModelsOct 15, 2016Status0 vote up vote down
Build a Miniature High-Rate Speed Control with BrakeModelsOct 15, 2016Status2 vote up vote down
Build an Analog Bar Graph Expanded Scale VoltmeterTestOct 15, 2016Status0 vote up vote down
Build an LED Bargraph Optical TachometerTestOct 15, 2016Status1 vote up vote down
Build an On/Off Motor Controller with BrakeControlOct 15, 2016Status0 vote up vote down
Building a Musical Sunrise Quartz Alarm ClockMusicOct 15, 2016Status0 vote up vote down
Chord EGG 2015: Remaking a PAiA ClassicMusicOct 15, 2016Status-1 vote up vote down
Retronome – A Versatile Analog Drum Machine for My Hammond OrganMusicOct 15, 2016Status3 vote up vote down
Make a Dual-Boot IDE CablePCOct 15, 2016Status-1 vote up vote down
Handheld GPS Glareshield (or Dashboard) Mount with Power SupplyMiscOct 15, 2016Status0 vote up vote down
Home built glow plug ignitor and remote controlModelsOct 16, 2016Status0 vote up vote down
Power Supply for Battery Valve RadiosTubeOct 16, 2016Status0 vote up vote down
RF Sweeper - VK2ZAYTestOct 17, 2016Status2 vote up vote down
Pure Sine-Wave Wien OscillatorTimingOct 17, 2016Status1 vote up vote down
Radar Detector - W1SNNMiscOct 17, 2016Status-1 vote up vote down
2 GHz to 10 GHz Cavity MultiplierRFOct 17, 2016Status3 vote up vote down
2 GHz - 7 GHz Wideband BPFFilterOct 17, 2016Status0 vote up vote down
900 MHz Trisection Microstrip BPFFilterOct 17, 2016Status0 vote up vote down
Metal Detector 650 kHzMetalOct 17, 2016Status2 vote up vote down
Metal Detector 1 MHz 3xBJTMetalOct 17, 2016Status1 vote up vote down
Metal Detector 3xBJT HomemadeMetalOct 17, 2016Status-6 vote up vote down
Metal Detector 5.5 MHzMetalOct 17, 2016Status-3 vote up vote down
Metal Detector 111 kHzMetalOct 17, 2016Status10 vote up vote down
Metal Detector 130 kHzMetalOct 17, 2016Status3 vote up vote down
Metal Detector 140 kHzMetalOct 17, 2016Status-3 vote up vote down
Metal Detector 300 kHzMetalOct 17, 2016Status1 vote up vote down
Metal Detector 300 kHz PLLMetalOct 17, 2016Status1 vote up vote down
Metal Detector 300 kHz PNPMetalOct 17, 2016Status23 vote up vote down
Metal Detector 455 kHzMetalOct 17, 2016Status2 vote up vote down
Metal Detector 625 kHzMetalOct 17, 2016Status6 vote up vote down
Metal Detector 4001 - ZL2PDMetalOct 17, 2016Status1 vote up vote down
Metal Detector Beat BalanceMetalOct 17, 2016Status3 vote up vote down
Metal Detector - JF1OZLMetalOct 17, 2016Status-1 vote up vote down
Metal Detector Pin DetectorMetalOct 17, 2016Status-1 vote up vote down
Metal Detector PLL 4046 BeachcomberMetalOct 17, 2016Status12 vote up vote down
Metal Detector Simple 3xBJT BFOMetalOct 17, 2016Status-6 vote up vote down
Metal Detector Surfmaster PiMetalOct 17, 2016Status28 vote up vote down
Metal Detector ToroMetalOct 17, 2016Status-50 vote up vote down
Ultrasonic Proximity Detector 2xBJTMiscOct 17, 2016Status0 vote up vote down
Precise Movement MeterMiscOct 17, 2016Status0 vote up vote down
Proximity Detector NE567MiscOct 17, 2016Status-1 vote up vote down
Charge-Pump Voltage Doubler with RegulatorPowerOct 20, 2016Status3 vote up vote down
Power Supply LCD meter Display - K1QWPowerOct 20, 2016Status-1 vote up vote down
12V to 110V/220V DC-AC 300W InverterPowerOct 20, 2016Status-2 vote up vote down
1.5V to 5V 200mA ConverterPowerOct 20, 2016Status-2 vote up vote down
DC Current MonitorMiscOct 20, 2016Status0 vote up vote down
Air-Speed Sensor for Cooling FanControlOct 20, 2016Status0 vote up vote down
Proportional Temperature Control for Gunnplexer - W4UCHMiscOct 20, 2016Status1 vote up vote down
Fan Speed Temperature Controller - DH8AGControlOct 20, 2016Status2 vote up vote down
Optical LED TransmitterLEDOct 20, 2016Status1 vote up vote down
Ultrasonic Bat Receiver - M0DGQMiscOct 20, 2016Status0 vote up vote down
Theremin with MC1496MusicOct 20, 2016Status2 vote up vote down
Zener Diode Emulator - WA5EKATestOct 20, 2016Status2 vote up vote down
Wireless IR Headphone RX-TX CD4046IROct 20, 2016Status-1 vote up vote down
Measuring speed of light using an oscilloscopeMiscOct 20, 2016Status-1 vote up vote down
Two chips LED Frequency Counter - PA2OHHTestOct 20, 2016Status1 vote up vote down
1 MHz to 1 GHz LED Absorption Meter - GW1TDVRFOct 20, 2016Status0 vote up vote down
True Linear RF Power DetectorRFOct 20, 2016Status2 vote up vote down
500 kHz to 3 GHz LED Field-Strength MeterRFOct 20, 2016Status1 vote up vote down
100 MHz - 2.5 GHz LED RF Signal Meter AD8313RFOct 20, 2016Status1 vote up vote down
800 MHz Phone Jammer ver.AMiscOct 20, 2016Status5 vote up vote down
Noise Canceling Electret Microphones - WB9YBMAudioOct 22, 2016Status0 vote up vote down
1W Audio Amplifier with CompressorAmplifiersOct 22, 2016Status-3 vote up vote down
High-Gain Audio Amplifier for Headphones - W7ZOIAmplifiersOct 22, 2016Status-6 vote up vote down
Active BPF 741 - WA5SNZFilterOct 22, 2016Status0 vote up vote down
1 kHz Quadrature OscillatorTimingOct 22, 2016Status0 vote up vote down
High-Impedance RF ProbeTestOct 22, 2016Status2 vote up vote down
Time Domain Reflectometry Generator - PA3DSCTestOct 22, 2016Status5 vote up vote down
Ultra Simple CRT OscilloscopeTubeOct 22, 2016Status-1 vote up vote down
400 kHz - 30 MHz Low Noise X-tal Oscillator - DJ2LRTimingOct 29, 2016Status0 vote up vote down
1 GHz Test Oscillator BFP450TestOct 29, 2016Status1 vote up vote down
DIY ECG Patient Simulator / ECG TesterMedicalOct 29, 2016Status-5 vote up vote down
Microscope conversion to LED-Light with two transistor current sourceLEDOct 29, 2016Status-1 vote up vote down
Precision Voltage Reference for Multimeter CalibrationTestOct 29, 2016Status0 vote up vote down
DIY LAN Cable TesterTestOct 29, 2016Status-2 vote up vote down
IR Remote Control JammerIRAug 21, 2021Status-2 vote up vote down
Doppler Radar Sensor using CDM324 24GHz radar modulesData AcquisitionSep 06, 2022Status1 vote up vote down
Analog front-end / amplifier for CDM324 24GHz radar moduleData AcquisitionSep 06, 2022Status1 vote up vote down
40MHz-Frequency counter with ATmega8TestSep 30, 2022Status0 vote up vote down
Solar powered, 2-cell Li-Ion battery charger using the LT3652SolarJan 28, 2023Status0 vote up vote down