There are 2698 circuit schematics available. Last circuit added on Sunday, 5 July 2015.

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CircuitCategoryDate AddedOK?Votes 
Battlefield Laser Warning Receiver - Front-End AmplifierLaserMay 30, 20153
Battlefield Laser Warning Receiver - Log Amplifier / Comparator / AlarmLaserMay 30, 20151
13.8V 30-40A Power Supply (PDF)Power 1
Yaesu FT-897 - PC interface (PDF)PC 0
AT89C2051 serial COMs to LED driverMicrocontrollerApr 12, 20010
RCM710 electronic scale, technical manual including schematicTestApr 12, 20011
RS-232 line monitor and loopback cablesPCJan 26, 20010
Serial to parallel converter using the AT89C2051MicrocontrollerJan 26, 20010
Slave flash trigger with counting logic (Silicon Chip Mazine article)PhotoAug 18, 20091
Design of active filters with operational amplifiers (includes circuit and Java filter calculator)FilterJan 16, 20100
Filters for the RadioJove ReceiverFilter 0
Autopilot: Do it yourself UAVModelsSep 10, 20060
Bridge headControlAug 14, 20020
Bat detector microphone pre-amplifiersPreamp 0
Visor cradle serial interfaceGamesAug 09, 20021
TomTom One V3 connector pinoutPDAMar 27, 20090
Simple CW Keyer based on Atmel ATtiny 2313Microcontroller 0
PWM motor controllerControlJun 06, 20030
Single and Two Cell White LED Drivers Without InductorsLEDSep 13, 20060
Laser link communicator project from Electronics Australia magazineLaser 0
12V battery level indicator for car batteriesAutomotive -1
Bicycle rear flashing LED lightLED 0
Car burglar alarm circuitAutomotive 0
Decision maker circuit diagramGames 0
Egg timer circuit diagram, PCB layout and assembly informationTiming 0
Electronic candleLighting -1
Flashing light / emergency beacon for vehicleAutomotive 0
3-up decision maker circuit diagramGames 0
Headlight guardAutomotive 0
Infrared beam door alarmIR -1
LED dice with fast rollGames 0
Interior light extenderAutomotive 0
Little bike light using LEDsLED 0
Simple metronome using LM1458Music 0
LED dice using PIC16F88Games 0
Simple moisture indicatorMisc 0
LM380 2.5 watt audio amplifier circuitAmplifiers 0
One transistor FM transmitter / FM bugging deviceTransmitters 0
Two player quiz master gameGames 0
4 channel 433MHz remote control transmitter / receiver based on SM5162 and SM5172 chipsRF 2
Seatbelt reminder circuitAutomotive 0
Solar trackerSolar 0
Stereo audio amplifier based on TDA2822MAmplifiers 0
Two LED trouble light systemAutomotive 0
Two-tone doorbell using 555 timerMisc 0
Two transistor FM transmitter / FM bugTransmitters 0
Snore alarm electronic deviceMedicalAug 14, 20020
AT89C2051/4051scanning 7-segment display and keypadMicrocontrollerJan 26, 20010
AT89C2051/4051 Driving dot LEDMicrocontrollerJan 26, 20010
AT89C2051/4051stepper motor interfaceMicrocontrollerJan 26, 20010
AT89C2051/4051connecting dumb terminalMicrocontrollerJan 26, 20010
Motorola 68K SBC (single board computer)MicrocontrollerJun 20, 20040
8051 SBC (single board computer)MicrocontrollerJun 20, 20040
8051SBC V1.1MicrocontrollerMar 25, 20090
Atmel 89 Series Device ProgrammerProgrammersMar 25, 20090
89S52 Project BoardMicrocontrollerMar 25, 20090
Digital Clock with Alarm Using DS1307TimingMar 25, 20090
Using the AT89C4051 as a RTC (real-time clock)MicrocontrollerMar 25, 20090
Home Automation Over InternetControlMar 25, 20090
Simple RS232C Level Converter using TransistorsMicrocontrollerJan 26, 20010
AVR ThermometerMicrocontrollerMar 25, 20090
Motorola 68HC11 evaluation boardMicrocontrollerJun 20, 2004-1
C-52 EVB Robot ControllerMicrocontrollerJan 26, 20010
Mains clock controller using AT89C2051MicrocontrollerJan 26, 20010
Data Acquisition & Logging System Using AT89c51 and Visual BasicData AcquisitionMar 25, 20090
DC Voltage and Current SourcePowerMar 25, 20090
Power supply provides +5VDC regulated, +10VDC unregulated and 7.5VACPowerJan 26, 20010
Controller for hybrid (photovoltaic- wind turbine and diesel engine) power plantPowerMar 25, 20090
AT89C2051/4051 Easy-DownloaderMicrocontrollerJan 26, 20010
AT89C51/52/55 Easy-DownloaderMicrocontrollerJan 26, 20010
PIC16F84 programmerProgrammersJan 26, 20011
PIC16F84 miniature real-time controllerMicrocontrollerJan 26, 20011
Isolated RS232 for PIC16F84MicrocontrollerJan 26, 20010
PIC16F84 debugging terminalMicrocontrollerJan 26, 20010
Big 7-segment LED display board with SPI interfaceLEDJun 20, 2004-1
MiniLOGGER V1.0MicrocontrollerJan 26, 20010
Analog datalogger based on T89C51RD2MicrocontrollerJun 20, 20040
RS232C Level ConverterPCJan 26, 20010
MTK-85 8085 Microprocessor Training KitMicrocontrollerMar 25, 20090
The 89C51 PABXTelephoneMar 25, 20090
PC electrically isolated RS422 interface using SN75176B or MAX485PCJun 20, 20040
PC electrically isolated RS485 interface using MAX487 or SN75176BPCJun 20, 20040
Short circuit protected power supply from PC 12V supplyPCJun 20, 20040
Atmel 89C Series Flash Microcontroller ProgrammerProgrammersJan 26, 20010
In-Circuit PIC Loader (ISP programmer) over parallel portProgrammersMar 25, 20090
PIC18F2550 Project BoardMicrocontrollerMar 25, 20090
3rd harmonic distortion meter for measuring the quality of AC supplyPowerMar 25, 20090
Data Acquisition System using ATmega8Data AcquisitionMar 25, 20090
Atmel 89C2051 prototype boardMicrocontrollerJun 20, 20040
Converter that enables long cable wiring for pyranometerSolarMar 25, 20090
AVR Line Following RobotModelsMar 25, 20090
Isolated Full Duplex RS232C InterfacePCJan 26, 20010
RS232 DB-9 switch to flip between two serial portsPCJun 20, 20040
Simple RS422 Converter for MiniloggerData AcquisitionMar 25, 20090
AT89C2051 real-time controllerMicrocontrollerJan 26, 20010
PIC12C508 Night-light saverMicrocontrollerJan 26, 20010
AT89C2051 Night light saverMicrocontrollerJan 26, 20010
Night light saver using AT89C2051LightingMar 25, 20091
Atmel 8051 Flash Based-Microcontroller ProgrammerProgrammersJan 26, 20010
CMOS control voltage for firing Crydom Soft-Start Motor ModuleControlMar 25, 20090
Solar energy meterSolarMar 25, 20090
Measure solar radiation on an Ubuntu ServerSolarMar 25, 20090
SPI Flash Microcontroller ProgrammerProgrammersMar 25, 20090
AT89Sxx Cheap and Simple Learning BoardMicrocontrollerMar 25, 20090
Sensor to display, built with thermistor, 12-bit ADC, 89S52 and LED displayTestMar 25, 2009-1
Thermistor Thermometer: LCD versionTestMar 25, 20090
AT89C2051 Digital thermometer and clockMicrocontrollerJan 26, 20010
Tiny 2313 Project Development BoardMicrocontrollerMar 25, 20090
Simple device for connecting serial instrument with RS485 or RS232 to the internetData AcquisitionMar 25, 20090
4-Channel Timer using Atmel 89C4051 and MAX7219 display driverMicrocontrollerJun 20, 20040
Digital timer with 7-segment display and pushbuttonsTimingMar 25, 20090
FAN Thermostat controlled by IR remote controllerControlMar 25, 20090
Car Ignition Coil Driver from 110V ACPowerSep 23, 20090
Laser beam alarm systemLaser 0
Amplified zener regulatorPower 0
13.5 Watt Power Amplifier using a TL081 opamp and TIP125 / TIP120 power transistorsAmplifiers 0
omentary High Voltage Arc Circuit - can be used to Ignite a barbeque or a Gas in a Potato GunMisc 0
Simple car battery voltage monitorAutomotive 0
Simple BFO metal detector using 2N3906 and 2N3904 transistorsMiscMay 30, 20070
Car Battery Charger, an SCR Design with a 10 Amp ratingAutomotive 0
Car Ignition Coil Driver from 12V DC - Can be used as an electric fencePowerSep 23, 20090
Cat or Dog Detector - can be used to control entry on a Cat or Dog DoorMisc 0
Battery Charger, Current and Voltage Regulated for Sealed Lead Acid batteriesPower 0
Digital Up / Down Counter with 7-segment displayLED 0
Delayed Power Circuit using an SCRControl 0
LED flasher with "Rising and Falling" BrightnessLEDSep 23, 20090
Ground Fault IndicatorTest 0
H-Bridge CircuitControl 0
12 Volt Knight Rider LED displayLEDSep 23, 20090
Digital combination lock using pair of CD4013 CMOS chipsAlarmsSep 23, 20090
Low battery cut-off circuit for a car or truckAutomotiveSep 23, 20090
Fish caller circuitMiscSep 23, 20090
Parabolic microphone project circuit (can be used with shotgun directional microphone also)AudioSep 23, 20090
Voltage and current regulated power supplyPowerSep 23, 20090
High current PWM controller based around a 555 timerControlSep 23, 20090
Electronic roulette wheel circuit diagramGamesSep 23, 20090
SCA Adapter - listen to advertisement free background music on FM broadcast radioRFSep 23, 20090
Simple Sine Wave Oscillator including a PCB layoutTimingSep 23, 20090
Solar cell battery charger circuit diagramSolarSep 23, 20090
Using a speaker as a microphone - impedance matching circuitAudioSep 23, 20090
Sound pressure level meterTestSep 23, 20090
Powerful stun gun / taser circuit diagramMiscSep 23, 20090
Simple switching power supply (mains operated)PowerSep 23, 20090
Relatively simple thermostat circuit diagramControlSep 23, 20090
Electric heater thermostatControlSep 23, 20090
TENS Circuit diagram for muscle stimulationMedicalSep 23, 20090
12 Volt Switching Power Supply circuit diagram and PCB layoutPowerSep 23, 20091
Ultrasonic sound detector / snifferMiscSep 23, 20090
Simple voltage booster based on Linear Technologies LT1372, includes PCB designPowerSep 23, 20090
True RMS Watt MeterTestSep 23, 20090
Two transistor FM transmitter circuit diagram and PCB layoutTransmittersSep 23, 20090
Making a bistable from a normal relay, based on coil hysteresisControlJul 21, 20130
Two-button control for dangerous machinesControlOct 05, 20120
Air flow detectorMisc 0
Bicycle LED POV (persistence of vision display) LED displayLED 0
GSM-900 Mobile Jammer Book (PDF compressed with WinRAR)TelephoneAug 01, 20100
Alkaline battery chargerPowerDec 02, 20020
PIC16F628 controlled FLL (Frequency Locked Loop) VFO for HF (PDF)MicrocontrollerOct 05, 20090
Direct Digital Synthesis VFO for HF Bands - based on Analog Devices AD7009 DDS (PDF)TimingOct 05, 20090
Simple Frequency Reader for conversion VFOsMiscOct 05, 20090
The u-counter, a PIC based programmable frequency meter (PDF)TestOct 05, 20090
Continuous Coverage V.F.O. for H.F. (PDF)TimingOct 05, 20090
Experimental DSB/CW QRP rig for 20 and 40 meter bands (PDF)RFOct 05, 20090
PIC16F84 CW decoder (PDF)MicrocontrollerJul 10, 20020
Simple 40 meters CW QRP Transceiver (PDF)RFOct 05, 20090
20 meters CW QRP Transceiver (PDF)RFOct 05, 20090
Heathkit modulated HeNe laser power supply kit (HK-HI1)Laser 0
Easy Xenon DC-DC Converter using LM386Lighting 0
Large collection of strobe / photoflash circuit diagramsPhotoSep 01, 20090
Slave Flash Trigger CircuitPhoto 0
Car power supply unit for digital projects, small car PCs etcAutomotive 0
Atmel AVR ATtiny45 development boardMicrocontrollerJun 28, 20110
RGB pattern generator based on an Atmel ATtiny2313 running at 20MHzVideoJun 28, 20110
Simple RS232 Level Converter based on a MAX232 including Eagle PCB and schematic filesPCJun 28, 20111
AVR thermometer / thermostat based on an Atmel ATtiny2313MicrocontrollerJun 28, 20110
PCB exposure countdown timer based on an Atmel ATtiny2313TimingJun 28, 20110
VCR ping pong gameGamesApr 27, 20040
Video ping pong gameGamesJul 10, 20020
Video Clock SuperimposerVideoJul 10, 20020
Video clock superimposer using PIC16C711VideoApr 27, 20040
Eddie's Composting Loo fan controllerMiscMar 09, 20120
Dual LED dice (available in kit form)Games 0
Single LED dice kit circuit diagramGames 0
Precision Digital AltimeterData AcquisitionMay 01, 20040
Highly accurate constant current source using LM4140, OP777 and MOSFETPowerMar 17, 20140
MOSFET based H-Bridge controller for DC motorsControlMar 17, 20141
Transistor delay circuits to detect if a door is open for a long periodAlarmsJun 24, 20151
Interfacing a DSLR Hotshoe to an ArduinoArduinoMar 27, 20140
Single supply op-amp audio amplifierAmplifiersJun 24, 20150
USB 0-500MHz RF Power Meter based on a AD8307RFFeb 21, 20130
Serial LCD controller using a PIC16F628Microcontroller 0
Advanced LED temperature indicatorLEDOct 25, 20140
Simple AM transmitter using a BFW10 FETTransmittersDec 07, 20140
Clap operated remove control for fansControlDec 07, 20140
Dry cell battery chargerPowerDec 07, 20140
Electronics Cricket on boardGamesMar 23, 20150
Electronics Lucky NumberGamesOct 25, 20140
Simple FM receiver based on a TEA5591 ICRFMar 23, 20150
Long Time Period Automatic TimerTimingOct 25, 20140
Microprocessor based home security systemMicrocontrollerOct 25, 20140
PC-based candle ignitor (parallel port based design)PCDec 07, 20140
PC-Based DC Motor Speed ControllerPCOct 25, 20140
Power Supply Resumption Alarm using 555 timerPowerOct 25, 20140
Presure based hit switchControlDec 07, 20140
Sensitive Optical Burglar AlarmAlarmsOct 25, 20140
Simple FM transmitter using a single transistorTransmittersMar 23, 20150
Simple quiz display using 74 series logic chipsGamesMar 23, 20150
Single chip dice using a 4060 chipGamesDec 07, 20140
Solid-state voltage indicator with high voltage cutoutPowerDec 07, 2014-1
Sound operated music bell using 555 timerAlarmsDec 07, 20140
Stabilized Power Supply With Short-Circuit IndicationPowerOct 25, 20140
Stereo audio simulatorAudioMar 23, 20150
Temperature Indicator Using AT89C52MicrocontrollerDec 07, 20140
Touch operated Band switch for Radio SetMiscOct 25, 20140
Trangular wave generatorTimingMar 23, 20150
Capacitor voltage stepper using 555 timerPowerDec 07, 20140
White / LF noise generatorAudioDec 07, 20140
Wind Sound GeneratorAudioOct 25, 20140
Home Built Laser ProjectorLaser 0
Arduino Mega 2560 schematic (PDF) - Arduino R3ArduinoJul 21, 20130
DPA 220 amplifier schematicAmplifiers 0
Low impedance microphone amplifierAmplifiers 0
DPA 440 amplifier schematicAmplifiers 0
Low pass filter for subwooferFilter 0
Portable Mixer with high-quality modular design (9V battery powered)Music 0
100W audio amplifier including PCB layoutAmplifiersApr 14, 20110
Quadraphonic Amplifier based on pair of LM1877 devicesAmplifiers -1
DPA 880 amplifier schematicAmplifiers 0
Class-A/AB Amplifier delivering 100W into a 4 ohm loadAmplifiers -1
Audio Indicator - monitor a loudspeaker, alarm, or audio source for presence of an audio waveformAudio 0
Stereo Audio IsolatorAudio 0
Guitar Reverb Effect Version 2Music 0
Guitar Reverb PedalMusic 0
Voltage Controlled PannerAudio 0
25 Watt MOSFET Audio Amplifier using IRF532 / IRF9532 hexfet transistors for output stageAmplifiers 0
Large capacitor charge "controllers" (Car Audio)Automotive 0
Easy to build DIY 50W amplifier based on ICL8063Amplifiers 0
Audio VU Meter based on pair of LM324 quad opampsAmplifiers 0
Voice-Over CircuitAudio 0
20 Watt Audio Power Amplifier using TDA2005MAmplifiers 1
22 Watt Stereo Amplifier using TDA1554Amplifiers 0
Two Transistors Audio AmplifierAmplifiers 0
10 Watt Audio Amplifier circuit diagramAmplifiers 0
Underwater microphone used in a home aquarium to monitor fish soundsAudio 0
DIY intervalometer for Sony NEX 5N cameraPhotoJun 14, 20150
DIY DC Amp Volt Watt Meter using an Arduino and ZXCT1010ArduinoJun 14, 20150
DIY Infrared Thermometer using Arduino Nano and MLX90614ArduinoJun 14, 20150
Speed limit alertAutomotiveJul 05, 20120
Motorcycle AlarmAlarmsJul 05, 20120
Car Alarm and ImmobilizerAlarmsJul 05, 20120
Car Hijack AlarmAlarmsJul 05, 20120
Motorcycle Alarm Number 2AlarmsJul 05, 20120
Motorcycle Alarm Number 3AlarmsJul 05, 20120
Motorcycle Alarm Number 4AlarmsJul 05, 20120
Motorcycle Alarm Number 5 & 6AlarmsJul 05, 20120
Park-Aid - Three LEDs signal bumper-barrier distanceAutomotiveJul 05, 20120
Headlight FlasherAutomotiveJul 05, 20120
Car Voltage Gauge with 7-segment readoutAutomotiveJul 05, 20120
Car Water Temperature Gauge with 7-segment readoutAutomotiveJul 05, 20120
Auto Burglar AlarmAlarmsJul 05, 20120
Automotive Speed IndicatorAutomotiveJul 05, 20120
Simple but reliable car battery tester using LM3914AutomotiveJul 05, 20120
Automotive 12V to +-20V converter (for audio amplifier)AutomotiveJul 05, 20120
Electronic car ignitionAutomotiveJul 05, 20120
Car battery charger with automatic cutoffAutomotiveJul 05, 20120
Automatic Headlight Brightness SwitchAutomotiveJul 05, 20120
Dome Lamp DimmerAutomotiveJul 05, 20120
Light switch using LDRControlJun 26, 20090
Digital Remote ThermometerMiscJun 26, 20090
Fridge door AlarmAlarmsJun 26, 20090
Room Noise DetectorAudioJun 26, 20090
Capacitive SensorMiscJun 26, 20090
Ultra-simple Voltage ProbeTestJun 26, 20090
Emergency Light & AlarmAlarmsJun 26, 20090
Heating System ThermostatControlJun 26, 20090
Touch switch based on CD4011 flip-flopControlJun 26, 20090
Door Alarm circuit diagramAlarmsJun 26, 20090
Mains Remote-Alert - Remotely operates beeper and/or a LED via mains supply lineMiscJun 26, 20090
Low Voltage Alarm for batteries and other volatile DC power sourcesPowerJun 26, 20090
Touch activated switch using CD4011 CMOS NAND gateMiscJun 26, 20090
Voice activated switch (VOX) circuit diagramMiscJun 26, 20090
Everything-that-moves alarm works by inducing eddy currents in living beingsAlarmsJun 26, 20090
Electronic locker digital combination lock circuit diagramAlarmsJun 26, 20090
Electronic Eavesdropping Devices DetectorRFJun 26, 20090
Simple Infa-Red Remote ControlIRJun 26, 20090
IR Remote Control Extender CircuitIRJun 26, 20090
Gate alarmAlarmsJun 26, 20090
Circuit diagram for 5 Zone Alarm SystemAlarmsJun 26, 20090
Miniature Loop AlarmAlarmsJun 26, 20090
Modular Burglar AlarmAlarmsJun 26, 20090
Water Activated AlarmAlarmsJun 26, 20090
Novel buzzer using a relay and transformerAudioJun 26, 20090
Radio Wave AlarmRFJun 26, 20090
Enhanced 5 Digit Alarm KeypadAlarmsJun 26, 20090
Enhanced 4 Digit Alarm KeypadAlarmsJun 26, 20090
Automatic Intruder AlarmAlarmsJun 26, 20090
Single Zone CMOS AlarmAlarmsJun 26, 20090
Travel Touch AlarmAlarmsJun 26, 20090
UltraSonic RadarMiscJun 26, 20090
Cuckoo sound GeneratorAudio 0
TRIAC Light DimmerLighting 0
LEDs or Lamps Sequencer is versatile modular design with no limits on number of lightsLighting 0
Battery-powered Night LampLighting 0
Courtesy light circuit diagramLighting 0
Brightness Control for small LampsLighting 0
12VDC Fluorescent Lamp DriverLighting 0
LED Chaser using 4011 / 4017 CMOS chipsLED 0
Adjustable Strobe LightLighting 0
Fading LEDsLED 0
Dancing LEDs circuit diagramLED 0
Black Light powered by a 6 volt batteryLighting 0
DC Motor Control CircuitControl 0
Fan control based on a TL082 opamp and IRF510 power MOSFETControl 0
Bicycle back Safety LightLighting 0
Simple LASER Transmitter/Receiver using HeNe laser tubeLaser 0
LASER Transmitter/Receiver using Pulse Width Modulator (PWM) for 12V / 24V applicationsLaser 0
Nocturnal Animals WhiskerMisc 0
Seven Component Regulated LED LampLED 0
LED Mood LightLED 0
13 Color LED Rainbow circuit diagramLED 0
Lightning Activated Camera Shutter TriggerPhoto 0
Electronic CanaryAudio 0
Metronome CircuitMusic 0
Sun - Up Alarm that provides an audible alarm when the sun comes up or a dark area is illuminatedAlarms 0
Assortment of Siren CircuitsAudioSep 17, 20090
60 LED ClockLED 0
Bike Light FlasherLighting 0
Simple 120 VAC motor speed controller based on a TRIACControl 0
PIC Light Chaser using PIC16C84Microcontroller 0
Wire tracerTest 0
Flashing neon christmas lightsLighting 0
Doorbell for the DeafAlarms 0
Insect RepellantMiscSep 17, 2009-1
220 Volts Flashing LampsLighting 0
IR Audio linkIRJul 05, 20120
Wireless IR headphone transmitterIRJun 28, 20090
Wireless IR headphone receiverIRJun 28, 20090
IR illuminator for night-vision tv cameras and scopesIRJun 28, 20090
Infra Red Switch that works with commonly available remote controlsIRJul 05, 20120
Infra Red Remote Control Extender (Mark 1)IRJul 05, 20120
IR Remote Control TesterTestJul 05, 20120
IR Remote Control Extender Circuit (Mark 2)IRJul 05, 20120
IR Remote Control Extender Circuit (Mark 3)IRJul 05, 20120
IR Remote Control Extender Circuit (Mark 4)IRJul 05, 20120
IR Remote Control Extender Circuit (Mark 5)IRJul 05, 20120
Infrared Remote Control that operates on 115 volts ACIRJul 05, 20120
Three channel audio spectrum analyzerAudioOct 21, 20090
Digital Voltmeter using ICL7107TestSep 17, 20090
Triangle / Squarewave Generator using a 1458 dual opampTimingOct 21, 20090
Beeper to find short circuitsTestOct 19, 20090
Voltage follower with 1G ohm input resistance based on LM11 opampPreampOct 21, 20090
Led display digital Voltmeter using ICL7107TestSep 17, 20090
MOSFET transistor testerTestNov 05, 20090
Precision Audio MillivoltmeterAudioSep 17, 20090
Oscilloscope testing module (huntron circuit)TestNov 10, 20090
Voltage Monitor using UA741 operational amplifierPowerOct 19, 20090
Logic probeTestOct 19, 20090
Digital Radar SpeedometerMiscOct 21, 20090
Digital Volume Control based around CD4067 CMOS chipsAudioOct 19, 20090
Electromagnetic Field Probe with Meter Output using an LF351 opampMiscOct 19, 20090
Three-Level Audio Power IndicatorAudioOct 19, 20090
Beat Balance Metal DetectorMisc 0
Coil Coupled Operation Metal DetectorMiscNov 10, 20090
Expanded Scale Battery Volt MeterPowerSep 17, 20090
Pulse Reading Logic ProbeTestOct 19, 20090
Stereo Test Tone GeneratorTestOct 21, 20090
Continuity Tester based on 4 x 2N3904 and 1 x 2N3905 transistorsTestOct 19, 20090
Audible Logic Probe based on LM339 operational amplifierTestOct 19, 20090
Single chip digital voltmeter using ICL7129TestNov 05, 20090
Latching Continuity Tester to help find intermittent faults, has quite a few innovative featuresTestOct 19, 20090
Infrared remote control tester using a SFH2030 photodiode and a CA3140 operational amplifierIROct 19, 20090
Linear Resistance MeterTestOct 19, 20090
XTal Tester for testing quartz crystals based on a pair of BC550C PNP transistorsTestOct 19, 20090
Simple RC car for beginners (Android control via Bluetooth)ModelsJun 14, 20150
Arduino RC car (Android control via Bluetooth)ArduinoJun 14, 20150
STM32 RC car (Android control via Bluetooth)ModelsJun 14, 20150
Lighting control with Android device through BluetoothLightingJun 14, 20150
Android controlled RC Vehicle with real-time video (Bluetooth & Wi-Fi)ModelsJun 14, 20150
Portable GSM900 Cellular Phone JammerTelephoneAug 01, 20100
High Power 800 MHz/AMPS Cellular Phone JammerTelephoneAug 01, 20100
Cellular Phone Jammer. Ver 2 circuit diagramTelephoneAug 01, 20100
Portable AMPS Cellular Phone JammerTelephoneAug 01, 20100
Portable AMPS Cellular Phone Jammer - Dual PurposeTelephoneAug 01, 20100
PCS Phone Jammer circuit diagramTelephoneAug 01, 20100
Portable PCS Cellular Phone Jammer circuit schematicTelephoneAug 01, 20100
PCS Cellular Phone Jammer circuit schematicTelephoneAug 01, 20100
GBPPR Cellular Phone Jammer Exciter schematic diagramTelephoneAug 01, 20100
Cellular Phone Jammer RF Amplifier circuit diagramTelephoneAug 01, 20100
Homebrew P2JBZ-style cellular / mobile phone jammer circuitTelephoneAug 01, 20100
Self-powered Fast Battery-Tester - Tests 1.5 to 15 Volt cellsTestSep 17, 20090
Battery Low Voltage BeeperPowerSep 17, 20090
AA Battery Solar ChargerSolarSep 17, 20090
4 Transistor Tracking TransmitterTransmitters 0
AM TransmitterTransmitters 0
FM Telephone BugTelephone 0
FM Transmitter using two transistorsTransmitters 0
AM/FM Simultaneous Transmitter Using Digital ICTransmitters 0
Medium range transmitter using pair of 2N3904 transistorsTransmitters 0
15 watt FM transmitter circuit diagramTransmitters 0
AM TransmitterTransmitters 0
Single transistor FM transmitterTransmitters 0
Small FM transmitter using SMD componentsTransmitters 0
Miniature FM TransmitterTransmitters 0
Low Power FM TransmitterTransmitters 0
FM Voice TransmitterTransmitters 0
Sensitive FM TransmitterTransmitters 0
Small FM TransmitterTransmitters 0
TV Signal Amplifier covers frequencies from 40MHz to 900 MHzVideoJun 28, 20090
Linear FM 50Watt with BLY90RFJun 28, 20090
Motorized Video Camera MountVideoJun 28, 20090
TV Transmitter - VHF band TV transmitter using negative sound modulation and PAL video modulationVideoJun 28, 20090
UHF Preamplifier covers 450MHz - 800MHz based on MPSH10 / BF180 / BCY90RF_AmplifierJun 28, 20090
60W Linear amplifier using IRF840 power MOSFETRF_AmplifierJun 28, 20090
Video Signal AmplifierVideoJun 28, 20090
Cellular Phone calling DetectorTelephoneSep 17, 20090
Simple Phone Tap circuit diagramTelephoneAug 12, 20090
Telephone Hold Button circuitTelephoneAug 12, 20090
Telephone recorder to record phone conversations automaticallyTelephoneAug 12, 20090
Cellular Phone calling DetectorTelephoneAug 12, 20090
Phone line indicatorTelephoneSep 17, 20090
Isolated Telephone InterfaceTelephoneAug 12, 20090
Telephone Record Control using 2N4360, 2N2222 and 2N2102TelephoneAug 12, 20090
Voice ScramblerAudioAug 12, 20090
Phone In Use Indicator circuit diagramTelephoneSep 17, 20090
Phone "Hold" With MusicTelephoneAug 12, 2009-1
Voice / Audio Record / Playback CircuitAudioAug 12, 20090
Simple speakerphoneTelephoneAug 12, 20090
High Quality Intercom using LM380 amplifier ICTelephoneAug 12, 20090
Soft Musical Telephone RingerTelephoneAug 12, 20090
Telephone amplifierTelephoneAug 12, 20090
Cut Phone Line DetectorTelephoneAug 12, 20090
Telephone line monitorTelephoneAug 12, 20090
Phone Busy IndicatorTelephoneAug 12, 20090
Ringing Phone Light Flasher using optocoupler and relayTelephoneAug 12, 20090
ADC conversion using ADC0804LCN and 8051Microcontroller 0
Build a Tape Linearizer and a Distortion AnalyzerAudioApr 14, 20100
Peak-reading metersAudioJan 26, 20010
Microphone polarity tester circuit diagranTestApr 14, 20100
Audio Spectrum Analyzer and Equalizer DesignsAudioMar 30, 20100
Build A Stereo SynthesizerMusicMay 07, 20100
Electronic Control for DC Motors Using Discrete Bridge Circuits (PDF)Control 0
Defeating SCMS on DAY recorders using a Sony CXD2601 chipAudioMay 07, 20100
Bell 202 and CCITT V23 Compatible FSK Modem CircuitPCOct 27, 20090
Strobo Disco Light Using Standard Tube Lamp (TL)Lighting 0
Heartbeat Sensor (Tranduscer)MedicalJan 08, 20140
Low Cost Universal Battery ChargerPowerJan 08, 20140
26V-to-5000V DC-DC ConverterPowerJan 08, 20140
Ring-Around LED FlasherLEDJan 08, 20140
Black Light (UV Tube Lamp) InverterLightingJan 08, 20140
15 Channels Cascaded MAX455 Video MuxVideoJan 08, 20140
Digital Encoder Circuit Using Stepper MotorControlJan 08, 20140
30-Khz Bandwidth High Linearity Opto-Isolated AmplifierAmplifiersJan 08, 20140
Three Wire RS232 To RS485 ConverterPCJan 08, 20140
Low-Drift High-Impedance JFET DC VoltmeterTestJan 08, 20140
Telephone Circuit: Music On HoldTelephoneOct 03, 20130
Loud 10-W Car Alarm SirenAutomotiveOct 03, 20130
Missing Pulse Detector Circuit with 555 ICMiscOct 03, 20130
Binaural Synthesizer/Mono to Stereo Converter for Small Speaker/PhonesAudioOct 03, 20130
Fast Charger for Better Lead-Acid Battery LifePowerOct 03, 20130
5 A Constant Voltage-Constant Current RegulatorPowerOct 03, 20130
Voltage Controlled Variable Gain Video AmplifierVideoOct 03, 20130
Tremolo Effect Circuit for Electric Guitar or Other Musical InstrumentsMusicOct 03, 20130
PC Audio Signal Generator Using RS232 PortPCOct 03, 20130
Powerline Carrier System Transmitter for Audio (Music/Speech)AudioOct 03, 20130
Compact 3W BTL Audio Power Amplifier TDA7056AmplifiersOct 03, 20130
CamTrig - A home-made light-operated camera triggerPhoto 0
A simple home-made light-operated camera triggerPhoto 0
A home-made light-operated camera trigger using the stamp microprocessorPhoto 0
Resistor decade boxTestAug 14, 20020
Gameboy MIDI interface circuit schematic and notes on Linux development for GameboyPDAFeb 05, 20101
Octave screamerMusicJan 26, 20010
Atari Punk Console schematicsGamesOct 04, 20100
Build A Roomba Bluetooth AdapterModels 0
Chaos generatorMiscJan 26, 20010
Various CNC mill circuit diagrams and other DIY CNC mill informationControlJun 17, 20110
Simple test equipment to buildTest 0
A Two-Way Morse Practice SetMisc 0
Send Morse on your VHF RigRF 0
An end-fed antenna, L-match coupler and resistive bridge for HFRF -1
Regenerative receiver for the AM broadcast band using two transistorsRF 0
Two Valve 40m CW TransmitterTransmitters 0
Novel crystal set requires no antenna, earthRF 0
80 meter direct conversion receiverRF 0
3 - 12 MHz Signal GeneratorTiming 0
A compact L-match ATU for portable useRF 0
80m ceramic resonator VXO CW transmitterTransmitters 0
RF Power Meter for the QRP measures up to 25 wattsTest 0
Converter to yune six metres on your two metre receiverRF 0
80 Metre DSB TransmitterTransmitters 0
High quality AM through your FM stereoRF 0
Signal Frequency Beat Frequency OscillatorTiming 0
Dip Oscillator for HFTest 0
Converter to Hear Amateurs on your FM RadioRF 0
RF Actuated Keying MonitorRF 0
LF to HF ConverterRF 0
CMOS IC 1 kHz Audio OscillatorAudio 0
One Valve CW transmitterTransmitters 0
1A Variable Regulated Power SupplyPower 0
Super 80 ultra-simple SSB receiver for 3.5 MHz a basic superhetRF 0
Two Tone Audio OscillatorAudio 0
Wide-swing Variable Crystal OscillatorTiming 0
Palm PDA based dataloggerPDA 0
Traffic light controller with 20-output sequencingModelsSep 10, 20060
4 Photo-Detector circuit with delayed release and bipolar outputAlarmsAug 18, 20090
5 Times Around CircuitModelsSep 10, 20060
8 Photo-Detector Circuit BoardData AcquisitionSep 10, 20060
Fast Electronic Circuit Breaker for Model RailwaysModelsNov 13, 20100
Automatic - Railway Grade Crossing Circuit (2008 design)Models 0
Audible Train Approach Warning CircuitModelsSep 10, 20060
Across The Track Infrared DetectorsModelsSep 10, 20060
Automatic Reversing Circuit for Model TrainsModelsNov 13, 20100
Voltage Comparator Information And CircuitsMiscApr 27, 20030
Block Occupancy Detector For DCCModels 0
Rail Crossing Diamond Protection CircuitModelsSep 10, 20060
Automatic Railway Grade Crossing FlashersModelsSep 10, 20060
H Bridge Motor Control CircuitsControlJun 09, 20020
Incline Railway Control CircuitModelsJan 01, 20030
Infrared Proximity Detector based on Vishay TSOP4830IR 0
LM3909 replacement using discrete componentsLEDFeb 14, 20030
Model Railroad Odometer CarModelsSep 10, 20060
Visible and Infrared Light DetectorsMisc 0
Turnout Anti-Derail Protection CircuitsModelsSep 10, 20060
Regulated Power Supply CircuitsPowerSep 10, 20060
Single Traffic Light Driver CircuitModelsNov 13, 20100
Basic Solid State RelaysPowerSep 10, 20060
Unipolar and bipolar stepper motor driver circuits using 74194 and ULN2803ControlNov 04, 20110
Various Transistor Throttles Cicuit SchematicsModelsSep 10, 20060
Three Terminal Regulator Type Throttle (LM350K)ModelsSep 10, 20060
1200 Watt Lamp Dimmer Circuit using Q4015LT combination DiacLightingSep 10, 20060
LM311 Thermostat circuit diagramsPower 0
10, 8 And 6 Step LED Circuits (CD4017)LEDSep 10, 20060
5 Second Ramp Generator for Locomotive Sound Card DemonstrationModels 0
Transformer Secondary Voltage ReductionPower 0
Adding External Meters to DC ThrottlesModels 0
Back And Forth - Bidirectional Bipolar Stepper Motor DriverPower 0
Grade Crossing Bell Ringer (LM555)Models 0
CA4060B Timer CircuitsTimingSep 10, 20060
Train Mounted Camera Battery ChargerModels 0
Using Common Cathode Or Anode LEDs As Bipolar LEDsLED 0
Timed Uncoupling Ramp Driver (LM555)ModelsSep 10, 20060
Colour Shifting For Bi-Colour LED'sLEDSep 10, 20060
Light Activated Detector Circuit (LM393/LM555)MiscSep 10, 20060
Diode Type Constant Lighting CircuitsLightingSep 10, 20060
High Side Current Monitors (LM358, Zetex - ZXCT-1009)PowerSep 10, 20060
Current Regulators For Light Emitting DiodesLEDSep 10, 20060
DCC To DC - Accessory Power SuppliesModels 0
Grouped DCC Block Occupancy DetectorsModelsSep 10, 20060
HIGH or LOW Power Switch For Lights or Small MotorsControlSep 10, 20060
High Impedance VoltmeterTestSep 10, 20060
Incandescent LED CircuitLEDSep 10, 20060
Model Railroad - Infrared Proximity SwitchModels 0
Infrared Receiver Module SchematicsIRSep 10, 20060
Various LM555 LED Blinker CircuitsLEDSep 10, 20060
Low Battery Voltage Cutout CircuitsPowerSep 10, 20060
Preselect Twin Coil Switch Machine CircuitPower 0
First Across The Line Race Scorer CircuitsModelsSep 10, 20060
School Bus Signals CircuitModelsSep 10, 20060
N.O. Magnetic Reed Switch ON /OFF Circuit (SCR equivalent)Power 0
Servo Motor Test Circuit (LM555)Test 0
Special Function Timer Circuits (LM555)TimingSep 10, 20060
Team digital - SCR16 - Twin Coil Switch Machine AdapterPower 0
LED Out Circuit For Tortoise Switch MachinesModels 0
Push Button Motor Control CircuitsControlSep 10, 20060
Timed DC ThrottleModelsSep 10, 20060
Efficient unipolar stepper motor driver (only uses power when it makes a step)Power 0
DCC - Zero Stretching Simulator (LM555)ModelsSep 10, 20060
Basic 10GHz / 24GHz gunplexer / gunn diode control circuit (PDF)RF 0
10 GHz CW Radar based on a X-band GunnplexerMisc 0
Self made data-logger V2.5 (second edition)Data AcquisitionNov 27, 20020
GoldPic 3 Pulse Induction Metal Detector (has electronic kit available)MiscMay 30, 20070
Apple IIe RGB to CGAVideo 0
Photodiode primer and interface circuit diagrams including photovoltaic and photoconductive modesMiscMar 04, 20100
Build a PIC controlled DDS VFO, 0 to 6 MHzMicrocontrollerJul 12, 20010
MBC5/CPLD for the GameBoyGamesOct 31, 20020
10W 2M CW transmitter circuit diagramTransmittersJun 19, 20110
50 MHz to 10 MHz receive converterRFJun 19, 20110
17M to 6M transveter circuit diagramRFJun 19, 20110
metre receiverRFJun 19, 20110
Passive grid (tube based) linear amplifierRF_AmplifierJun 19, 20110
T-Match ATU (antenna tuning unit)RFJun 19, 20110
Fourth order Butterworth BPF circuit diagram and design notesFilterJun 19, 20110
Frequency counter based on PIC16F628 and LCD displayTestJun 19, 20110
10MHz GPS disciplined frequency standardTimingJun 19, 20110
Iambic keyer based on a PIC16F84 or PIC16C84MicrocontrollerJun 19, 20110
Chebyshev low pass filter, rolls of at 30MHzFilterJun 19, 20110
PIC18F4550 Development Board including PCB layout suitable for home etchingMicrocontrollerJun 19, 20110
Single transistor receiver for SSB, CW, AM using a VHF dual gate MOSFETRFJun 19, 20110
Multi band SSB transceiver construction projectRFJun 19, 20110
Receiver building blocksRFSep 06, 20010
Digital display and VFO stabiliser using a PIC microcontroller and LCDRFJun 19, 20110
SSB transceiver for 80MRFJun 19, 20110
Simple CW transmitter for 80MTransmittersJun 13, 20110
VHF receiver convertererRF 0
Parallel AVR programmerProgrammersMay 01, 20040
Europa30, a 10MHz QRP TXTransmitters 0
A Receive Signal DecoderModelsOct 30, 20020
Motor speed controllersControlJun 17, 20030
How to install LED lights to Mini-Z model car (based on PIC12C509)GamesNov 05, 20090
Alternative power source for Magellan GPS receiversPowerMay 01, 20040
PIC16F84 line following robotMicrocontrollerJan 26, 20010
8 x 8 Audio-video switchVideoMar 23, 20030
Commodore 64 24-bit parallel port interface with 8255PCMar 23, 20030
PIC16C505 IR / wireless remote controlMicrocontrollerMar 23, 20030
DIY 2^16 encoder based on PICMicrocontrollerApr 12, 20140
Electronic door codelock (PIC16F84)AlarmsMar 23, 20030
Automatic door opener with PIC12C508MicrocontrollerMar 01, 20010
Full-duplex doorphone with 3 wires connectionMiscMar 23, 20030
Infrared gate for doorIRMar 23, 20030
Infrared circuits for remote controlIRMar 23, 20030
Serial port controller infrared transmitter (PIC16F628)IRMar 23, 20030
Dual light timer based on PIC - Automatically turn off the lights after 10 minutesLightingApr 12, 2014-1
3-wire serial LCD interface for the PICMicrocontroller 0
Learning IR remote control receiver using a PIC16F628IRApr 12, 20140
Low impedance microphone amplifierPreampMar 23, 20030
RS485-like multi-drop bus with half duplex serial protocolMicrocontrollerMar 23, 20030
EPCOS Principles of SAWR-stabilized oscillators and transmitters application notes (PDF)TransmittersApr 12, 20140
Circuit diagrams for 418/433 MHz short-range communication (Elektor Electronics article)RFApr 12, 20140
88 - 108MHz FM audio transmitter / bug circuit diagramTransmittersApr 12, 20140
Circuit diagram for superregenerative receiver built by GE labsRFApr 12, 20140
X10 RF daughter board - receiver circuit diagramRFApr 12, 20140
RX3302 433MHz superregenerative receiver module circuit diagramRFApr 12, 20140
Automicro RX3304 receiver module schematicRFApr 12, 20140
Automicro TM02 high power data transmitter module circuit diagramTransmittersApr 12, 20140
27MHz toy car receiver L4=9 turns, .15mm wire on 4.5mm diameter tunable ferrite coil formerModelsApr 12, 20140
SAW-based 434MHz transmitter schematic with RO2101 1-port SAW resonatorTransmittersApr 12, 20140
Simple VHF video transmitter / video modulator circuit diagram (not FCC approved)VideoApr 12, 20140
500MHz video signal transmitterVideoApr 12, 20140
RF Audio transmitter circuit diagram that operates in the AM broadcast bandTransmittersApr 12, 20140
49MHz walkie-talkie circuit diagram that uses only three transistorsRFApr 12, 20140
Superregenerative 27MHz receiverRFMar 23, 20030
LCD thermometer using PIC16F871Microcontroller 0
Electronic irrigation controller based on PICMicrocontroller 0
USB digital I/O extender using a PIC18F14K50PCApr 12, 20140
220V live wire-in-wall scannerTestMar 23, 20030
Opendiag OBD-II Schematics & PCB Layout Opendiag OBD-II Schematics & PCB LayoutAutomotive 0
G Strain energy absorberMiscJan 01, 20030
Test oscillator that generates sinewaves, squarewaves, and triangle wavesTestFeb 20, 20130
PPMScope DIY oscilloscope with 1MHz sampling rate and Windows softwareTestFeb 20, 20130
'Almost No Parts' 7-segments 12/24 Hours LED clock with PIC 16F84A or 16F628AMicrocontrollerSep 25, 20090
FM Microphone micro-transmitter that is small and sensitiveTransmitters 0
Montreal Doppler 3 DF (direction finder) unitRFApr 14, 20110
A PIC-based "TDOA" RDF (radio direction finder) antenna unitMicrocontrollerApr 14, 20110
Construction details for 30 meter rig with superhet receiver and crystal controlled transmitterRFApr 12, 20140
All Discrete Components 40 M transceiver with super-het receiver using no IC'sRFApr 12, 20140
Versatile L tuner for end feed wire antennas that fits in an Altoids tin.RFApr 12, 20140
MMR-40 40 meter rig with SSB (voice) and CW (Morse code) operating modes.RFApr 12, 20140
Battery voltage monitor using an LM358 op-ampPowerApr 12, 20140
KD1JV Digital SWR / Power MeterTestApr 12, 20140
An 80 meter rig for the MAS contest by KD1JVRFApr 12, 20140
A unique PSK transceiver, Version 2 By Steven Weber, KD1JVRFApr 12, 20140
(Fairly) Simple 75M SSB rig with PTTRFApr 12, 20140
AM Short Wave Broadcast Receiver circuit diagramRF 0
Low Power Antenna Analyzer and ATU Tuning AidTest 0
Voltage boost and buck circuits using Atmel AVR Tiny13V for driving a white LEDLEDMar 09, 20120
Fixed Frequency "Tuner Dipper"Test 0
0-14 volt, 0-2 amp current limited variable power supply regulatorPower 0
A Variable power supply with adjustable current limiting. 0-14V output up to 5A current.PowerApr 12, 20140
Simple WWV receiver for 10 MHz calibration signalTimingApr 12, 20140
Microcontroller (AT89C2051) based tachometer (PDF)AudioNov 13, 20100
GSM SMS javljalnik ALSMS-01 (page in slovenian )SMS remote control projectControlOct 07, 20090
Singing Christmas tree based on Microchip PIC16F84MicrocontrollerOct 07, 20090
DDS/PLL based VFO synthesizerTimingOct 07, 20090
Universal USB digimode interface supports CAT (Yaesu), CI/V (Icom) and RS-232 (Kenwood) units (PDF)RFOct 07, 20090
50 MHz frequency counter, voltage meter & SWR/PWR indicatorMicrocontrollerJul 12, 20010
Universal frequency counter & voltage meterTestOct 07, 20090
Convert 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radioRFJun 18, 20030
Simple CW identifier for a FM repeater (PDF)RFOct 07, 20090
Transceiver to PC soundblaster interface for digital operating modes (PSK-31, RTTY, SSTV etc)PCOct 07, 20090
6m SSB & CW QRP transceiverRFOct 07, 20090
80m SSB & CW QRP superhet transceiverRFOct 07, 20090
Transceiver to PC interface with a hardware DTMF detector and galvanic isolation (PDF)PCOct 07, 20090
Pocket sized 20m (30m) CW QRP transceiverRFOct 07, 20090
USB / CAT (CI-V) adapter tested with FT-8900, FTB-9800, VX-7R, VX-7, FT-817 and IC-706MkIIGRFOct 07, 20090
Amateur weather station to APRS interface ALWXI-01MiscOct 07, 20090
Collection of quartz crystal ladder filter circuit diagramsFilterOct 07, 20090
Building a Digital Intervalometer - includes circuit diagram and suggested layoutPhotoMay 09, 20100
Serial LCD Controller using Microchip PIC16F628Microcontroller 0
Arduino based motion triggered camera using a PIR sensorArduinoNov 13, 20100
Dynamo Current and Voltage RegulatorPowerSep 21, 20060
Wideband SWR meterRF 0
Spring reverb unitAudioJan 26, 20010
Incoming call indicator (ZIP file)TelephoneJan 26, 20010
A 3m (100 MHz) small bug (ZIP file)TransmittersJan 26, 20010
Digital speedometer for cars with 7-segment display of speedAutomotiveJun 28, 20110
PC serial port parastic mode interface for 1-wire DS18S20 and similar 1-wire temperature sensorsPCJun 28, 20110
Homebrew Wired Remote for Canon EOS 350D CameraPhoto 0
Dreamcast PC serial adapterGamesOct 23, 20020
How to use a SCART TV as a Monitor for MAME arcade game emulatorGames 0
SCA Subcarrier Demodulator for FM broadcast stationsRF 0
ESR MeterTestMay 17, 20020
Line Output / Flyback transformer testerTestMay 17, 20020
LED Voltage Indicator BoardLED 0
Voice Message Recorder / Player (uses an obsolete voice recorder chip)Audio 0
BC547 80M SSB QRP TransceiverTransmitters 0
Timer circuit based on a 14536 and 4011 CMOS chips that can be calibrated using a frequency counterTimingJan 31, 20100
Circuit diagram for basic alarm with delayed triggerAlarmsFeb 09, 20100
General purpose portable DC power supply using rechargeable C cellsPowerFeb 05, 20100
PCB board tester and RF detector circuir diagramsTestFeb 09, 20100
Alarm circuit to remind you to turn off your DMM (digital multimeter)TestJan 31, 20100
Circuit to enable cycling a string of Christmas lightsLightingJan 31, 20100
Pseudo car alarm systemAutomotiveFeb 05, 20100
45 to 90Hz hum filter circuit diagramFilterSep 13, 20060
Sound alarm based on LM741 opamp and LM386 amplifierAmplifiersFeb 09, 20100
General purchase audio preamplifier based on pair of 2N2222 transistorsPreampJan 31, 20100
Audible timer that can be used as a cooking timer for roasting peanuts for exampleTimingJan 31, 20100
Wireless alarm FM transmitter moduleAlarmsFeb 09, 20100
Switch debouncer circuits including transistor, CMOS logic and a 555 timer based designMiscJan 31, 20100
Percussion generator circuitsMusicFeb 09, 20100
Bench power supply that allows a number of varying output voltages to be preset. Includes PCB layoutPowerFeb 26, 20100
Small audio amplifier based on LM386AmplifiersJan 31, 20100
Function generator based on 555 timer and three 2N2222 transistorsTestFeb 05, 20100
Interesesting circuits using diodes ideal for education or introductory courses on electronicsMiscFeb 20, 20100
Sequential flashing arrow circuit using a 4017, also includes a PCB layoutLEDFeb 26, 20100
Selection of run circuits to experiment with the 4017 CMOS decade counter chipMiscFeb 26, 20100
Notes on using LEDs and various LED driver circuit diagramsLEDFeb 26, 20100
Multi-trace scope display that allows up to 4 channels to be viewed on a single oscilloscope channelTestFeb 26, 20100
Small circuit and PCB layout for recording to PC Sound Monitor / Pre-ampPCFeb 26, 20100
FM Microphone transmitter / FM buf circuit diagramTransmittersJan 31, 20100
Model Train Diesel & Horn Sound ModuleModelsMar 30, 20100
Magentic phono cartridge phono preamp circuit diagramPreampFeb 05, 20100
Power supply metering circuits for measuring both voltage and currentPowerFeb 09, 20100
Cicuit diagram for super long range microphone for use with a shotgun microphone or parabolic dishAudioFeb 20, 20100
Fuse or line monitor that will check the status of up to six fuses including a PCB layoutAlarmsFeb 20, 20100
Variety of applications using a CMOS 4001 2-input NOR gate including a PCB layoutMiscFeb 20, 20100
Select of interesting electronic circuits that require only a single transistor ideal for educationMiscFeb 20, 20100
Small selection of useful circuitsMiscFeb 09, 20100
Variety of simple motor control circuit diagrams using SCR or TRIACControlFeb 20, 20100
Super mixer with microphone input / amplifier including a PCB layoutAmplifiersFeb 20, 20100
Selection of 14 oscillator circuits include sinewave, audio, logic and LED flashersTimingFeb 20, 20100
Jeopardy game circuit diagram using three CMOS logic chipsGamesFeb 09, 20100
Selection of audio preamplifiers including circuits suitable for battery operationPreampJan 31, 20100
DDS from 1-60 MHz with built-in amplifier and variable output level using Analog Devices AD9851Test 0
Ericsson phone to PC serial port interfacePCNov 29, 20020
Network car controller provides functions for remote door locks, headlight reminder, and car finderAutomotiveMay 16, 20100
Emergency power systemPowerMay 16, 20100
Digital bench power supply based on a PIC16F870PowerMay 24, 20100
Candle simulator based on a PIC12F675 microcontrollerLightingMay 16, 20100
Magnetic card reader to PC RS-232 port interface based on a PIC12F675 microPCMay 24, 20100
Cat toy using a PIC12F675 and a small weighted motor to keep your cat amusedGamesMay 24, 20100
Dirt cheap video using a PIC16F819 microcontrollerMicrocontrollerMay 16, 20100
Dremel drill speed controllerControlMay 16, 20100
Talking Egyption frog boxGamesMay 24, 20100
Talking fish hack using a PIC16F819 microcontrollerMicrocontrollerMay 16, 20100
Furby Resurrection - Project that replaces the electronics in a Furby with new custom electronicsGamesMay 24, 2010-1
PWM Heater fan controller based on PIC12F675ControlMay 24, 20100
Hexbot robot based on a PIC including source code and circuit diagramModelsMay 16, 20100
433MHz super remote control using a PIC12F683 to boost rangeTransmittersMay 24, 20100
Home theater systemAudioMay 24, 20100
Beam robot / insect based on a PIC16F818 microcontrollerModelsMay 24, 20100
Infrared object detector using a PIC12F629 microcontrollerIRMay 16, 20100
Isolated oscilloscope probeTestMay 16, 20100
Telephone line simulator ideal for testing phone interface projectsTelephoneMay 24, 20100
Lithium Ion Battery Charger based on a PIC micro including circuit diagram and source codePowerMay 24, 20100
Marshmallow Bazooka with a PIC12F615 based capacitor discharge ignition systemMiscMay 16, 20100
Colour Organ based on a PIC16F84 microcontroller including schematics and source codeMusicMay 24, 20100
Touch sensistive touchpad based on a PIC16F627A microMiscMay 24, 20100
Self-powered phone messenger based on a PIC16C819 microcontrollerTelephoneMay 24, 20100
Phone call interceptor to stop unsolicited phone callsTelephoneMay 16, 20100
Telephone call screener with voiceTelephoneMay 24, 20100
Remote RF transmitter based on PIC12F675 or PIC12F629TransmittersMay 24, 20100
Remote infrared terminal for projects requiring IR communicationsIRMay 24, 20100
RS-232 to TTL level translatorPCMay 16, 20100
DIY flying saucer / UFO using a PIC microcontrollerGamesMay 16, 20100
Solar charge controller based on a PIC microcontroller including schematic and source codeSolarMay 16, 20100
SD card interface for PIC microcontroller including schematic and source codeMicrocontrollerMay 16, 20100
Function Generator Sine / Triangle / Square / Saw / Burst Sweep Noise based on PIC16F870TimingMay 16, 20100
Circuit monitoring device logs for over 10 days and can log up to 32k events both digital and analogData AcquisitionMay 24, 20100
Superprobe handheld test device based on a PIC16F870TestMay 24, 20100
Speech Synthesizer Development System using a PIC microcontrollerMicrocontrollerMay 16, 20100
Toy car hack to turn it into a synthetic rodentModelsMay 24, 20100
PIC micro programmer that runs under MAC, Win98, XP, Vista, DOS, Linux, etcProgrammersMay 24, 20100
Video switcher to allow monitoring of multiple video cameras using a single monitorVideoMay 24, 20100
Low cost video motion detection using a PIC16F819 and an LM339VideoMay 24, 20100
YoYo enhancement device using a PIC12F629 to provide LED lighting effectsLEDMay 24, 20100
Electric cockroach zapperMiscMay 24, 20100
Programmer PIC16F84,12C50x and EEPROM 24CxxProgrammersAug 14, 20020
Build an inexpensive Hall effect GaussmeterTest 0
Design for a slightly more expensive GaussmeterTest 0
Home-Built Magnetic LevitatorMisc 0
Project for experimenting with magnetic levitationMisc 0
Adaptive Windscreen Wiper ControlAutomotiveApr 14, 20030
Portable iPod chargerPDA 0
FET based metal detector using MPF102 / J310 BF998 FETsMiscMay 30, 20070
Ultrasound detectorMiscSep 13, 20060
IC tone control preamplifier using single 741 opampPreampJul 03, 20110
1KHz 4th order Butterworth filter using LT1367 quad operational amplifierFilterJul 03, 20110
1.5 volt FM transmitter circuit diagramTransmittersJul 03, 20110
10-30 watt stereo audio amplifier circuitAmplifiersJul 03, 20110
118MHz to 136MHz aircraft receiver circuit diagramRFJul 03, 20110
12V 300W 4 channel car amplifier schematic diagramAutomotiveJul 03, 20110
1300MHz - 1500MHz transmitter with 20 - 50mW output powerTransmittersJul 03, 20110
1300MHz - 1500MHz antenna with amplifier based on two MAR-8 RF amplifiersRF_AmplifierJul 03, 20110
15W mono car amplifier using TA7227PAutomotiveJul 03, 20110
Shortwave received circuit diagramRFJul 03, 20110
Two transistor audio preamplifier with volume controlPreampJul 03, 20110
20KHz Butterworth active filter using Linear Technology LT1124, LT1355 or LT1169FilterMay 25, 20120
2W / 4W audio amplifier using pair of LA4100, LA4101 or LA4102 modulesAmplifiersMay 25, 20121
455KHz oscillator using FET and 455KHz IF transformerTimingMay 25, 20120
6W mono car amplifier using BA521 or BA532 amplifier moduleAutomotiveMay 25, 20120
Basic logarithmic amplifier using op-amp and NPN transistorPreampJul 03, 20110
Beat frequency oscillator for AM/SW radio receiversRFMay 25, 20120
Direct conversion 7MHz receiver using NE602RFMay 25, 20120
Low voltage microphone preamplifier using LM10PreampMay 25, 20120
Micro TV transmistterVideoMay 25, 20120
Mono audio preamplifier using single 2SC732 transistorPreampMay 25, 20120
Relay interface to R/C receiversModelsMay 25, 20120
Small TV transmitter for CCTV observationVideoMay 25, 20120
VCR head amplifier testerTestMay 25, 20120
Video line receiver using AD818VideoMay 25, 20120
Wireless guitar transmitterMusicMay 25, 20120
Wireless microphone using 741 opamp and 2N3904TransmittersMay 25, 20120
WWV receiverRFMay 25, 20120
Casio calculator interface schematicPDASep 10, 20060
Conrad Electronics MM3610D multimeter cable pinoutTestSep 10, 20060
1.5 GHz PLL Frequency SynthesizerRFApr 10, 20140
Tiny EEG interface schematicMedical 0
OpenEEG open hardware EEG projectMedical 0
Fitting a JTAG interface to an iPAQ 3600PDASep 10, 20060
Diode laser electronic circuits for atom opticsLaser 0
Build Your Own Video-Rate 2-photon MicroscopeMiscSep 25, 20090
LED driving and controlling methods including constant current drivers and PWM brightness controlLEDJul 11, 20120
Touch senstor based on Atmel AT90S2313Microcontroller 0
VHF/UHF TV modulatorVideoNov 16, 20020
Programming hardware and softrware for 14-bit FLASH PIC microcontrollersProgrammersFeb 25, 20110
Single cell LED flasher with two-year battery life (LM3909 replacement)LED 0
Volvo 164 electric fan thermostatAutomotiveFeb 25, 20110
RS232 to RS485 converter schematic to connect PC to RS485 networkPCApr 09, 20100
RS232 serial to USB converter cable circuit schematicPC 0
Sony RS-422 ADAT sync cable pinoutMiscSep 10, 20060
Mac to HP48 cable pinoutPCSep 10, 20060
Digital cameras (AGFA, Olympus) to PC (COM) cable pinoutPhotoSep 10, 20060
Garmin Foretrex 101,201, Forerunner 101,201 to Serial DB9 cable schematic pinoutMiscSep 10, 20060
Apple iPod and iPhone dock pinoutPDASep 13, 20060
Palm Pilot, Palm III, V, VII, VIIx, Handera interface port pinoutPDASep 13, 20060
Car OBDII diagnostic interface cable schematic pinoutAutomotiveSep 10, 20060
Car OBD II J1850 PWM, J1850 VPW, ISO-9141 cables schematic pinoutAutomotiveSep 10, 20060
Simple DTMF Repeater Controller using PIC16F84Misc 0
LCD clock based on AVR Attiny2313Microcontroller 0
Music player built on microcontroller AT91SAM7S256 with ARM coreMusic 0
Build a Simple Bat DetectorMiscJan 08, 20140
Various radio control schematicsModels 0
Linear constant current source dimmer for a white 24-LED arrayLEDMar 03, 20110
Simple current limiting for LED flashlightsLEDMar 03, 20110
Single-Wire-Telephones for caves and minesTelephoneMar 03, 20110
Transverter for Converting SSB CB to LF for Thru-the-Earth Voice CommunicationsRFMar 03, 20110
A simple and inexpensive laser power meter (PDF)LaserFeb 21, 20130
101 AT Keyboard to ASCII Decoder using 68HC705J1A MCUMicrocontrollerJan 26, 20010
Traffic light controller using an Arduino microcontrollerArduinoAug 26, 20100
Simple ADS-B aircraft transponder decoder based on a PIC18F2550 microcontrollerRFDec 09, 20100
PIXpand - TI calculator to Playstation memory card interfaceMicrocontrollerJul 12, 20010
Constant current LED driver schematic using a pair of BC547 transistorsLEDJul 11, 20120
Simple laser communicatorLaserJun 09, 20020
Arduino UNO based CW decoderArduinoJun 24, 20150
PIC 18 programmer (PIC18F458, PIC18F452, PIC18C252, PIC16C745, PIC18F6620, PIC18F6720)ProgrammersJun 06, 20030
Game boy camera PC serial interfacePCSep 13, 20060
Build a synchronous clock locked to the mains frequencyTimingAug 18, 20090
Simple Class A Amplifier - 10W audio outputAmplifiersJan 22, 20100
Better Volume (and Balance) control circuit diagramsAudioApr 14, 20100
Low Noise Microphone PreamplifierPreampJun 04, 20100
Bridging Adapter For Audio Power AmplifiersAmplifiersJan 29, 20100
Audio MillivoltmeterTestApr 14, 20100
'A' Weighting Filter For Audio MeasurementsFilterSep 13, 20060
Simple surround sound decoder circuit schematicAudioApr 14, 20100
Stereo Width ControllersMusicMay 07, 20100
Power Amplifier Clipping Indicator Circuit DiagramAmplifiersJan 29, 20100
Collection of phono preamplifier circuitsPreampApr 21, 20100
Digital Delay Unit For Surround SoundMusicMay 07, 20100
100W Guitar Amplifier Mk II circuit diagramMusicJan 29, 20100
Parametric And Sub-Woofer EqualiserAudioApr 14, 20100
High Quality Audio MixerAudioMar 17, 20100
Simple Car Preamplifier and Artificial EarthPreampJan 29, 20100
Loudspeaker Protection and MutingAudioJan 29, 20100
Spring Reverb Unit For Guitar or KeyboardsMusicApr 14, 20100
Audio Signal Detecting Auto Power-On UnitControlMar 30, 20100
Soft-Start Circuit For Power AmpsAmplifiersMar 30, 20100
Mains Power Load Sensing Automatic SwitchControlMar 30, 20100
Thermo-Fan to keep your amplifier or other equipment coolControlMar 30, 20100
Guitar Vibrato Unit Circuit DiagramMusicApr 14, 20100
Microphone Circuit Test OscillatorTestApr 14, 20100
Distortion analyser circuit diagramTestApr 14, 20100
VU And PPM Audio MeteringAudioMay 07, 20100
Variable Amplifier ImpedanceAmplifiersMar 30, 20100
The ESP SIM (Sound Impairment Monitor)TestApr 14, 20100
Linkwitz Cosine Burst GeneratorTestApr 14, 20100
Multiple Feedback Bandpass FilterFilterNov 01, 20020
High quality audio preamplifier (OPA2134)PreampSep 13, 20060
Automatic Charger for Battery Operated Hi-Fi PreampsPreampJun 17, 20030
Capacitance to Voltage conversionMisc 0
LED dice project based on 555 timer and CD4017 decade counterGames 0
CMoy pocket headphone amplifierAmplifiers 0
Biasing Op-Amps into Class AMiscJan 01, 20030
Laser high-voltage power supplyLaserOct 06, 20060
THE FOX - 40 milliwatt transmitterTransmittersApr 14, 20110
THE FOX 750 - 750 milliwatt transmitterTransmittersApr 14, 20110
Active RF antennuatorRFApr 14, 20110
FOX BOX - Transmitter controllerTransmittersApr 14, 20110
Amplified field strength meter / RF snifferTestApr 14, 20110
THE FOX - 250mw transmitter with timerTransmittersApr 14, 20110
Simple Time-Difference-Of-Arrival RDFRFApr 14, 20110
555 Time-Difference-Of-Arrival RDFRFApr 14, 20110
PIC-Bot II using Microchip PIC16LF84Models 0
Arduino MIDI interface (Arduino MIDI Drum Kit and Spooky Sound Trigger)ArduinoAug 26, 20100
Solar robotsSolarNov 16, 20020
Bleeper box for time referenceMiscMay 01, 20040
3 in one tester (audio, tone generator, diode/circuit tester)Test 0
50MHz converter project based on a NE602/SA602/NE612RF 0
AF variable frequency generator using 555 ICTiming 0
Regulatable audio amplifier using a 741opampAmplifiers 0
HF/6M Antenna Tuner Preselector and Antenna SwitcherRF 0
Bass EQ pre-amp correction for high impedance ceramic crystal pickupAmplifiers 0
300/1200 baud BAYCOM MODEM (revision and improved)PC 0
Direct Crystal radio receiver examplesRF_Amplifier 0
Crystal switcher using diodesTiming 0
MW Enhanced Crystal Receiver using 741 ICRF 0
455 Khz MF to AF converter used for DRM reception in a Yaesu FRG-100 receiverRF 0
Emergency light flasher schematicLighting 0
Sensitive LW/MW/SW Shortwave general coverage receiverRF 0
HAMCOM (SSTV, RTTY, FAX...) modem using PC-speaker for TXPC 0
10 meter (28MHz) band RF amplifierRF_Amplifier 0
12 watt audio amplifier with tone using TDA1020Amplifiers 0
5 watt audio amplifier using TDA1010Amplifiers 0
Low frequency / audio frequency dB output meterAudio 0
Basic low frequency preamplifier circuitsPreamp 0
Microphone pre-amp with high emphasisPreamp 0
MW/SW Radio receiverRF 0
Bipolar transistor RF mixerRF 0
IC oscillator 1...30MHz using 74LS04 chipTiming 0
Simple AF-oscillator / signal generator using pair on 2N2222 transistorsTiming 0
HF/VHF mini portable antenna tunerRF 0
Microphone preamp for portable transceiversPreamp 0
Wideband VHF/UHF/SHF 22dB RF preamp with MAR-6 or MAR-8 (MSA-0885)RF_Amplifier 0
PTT and/or soundcard interfacePC 0
PTT and soundcard interface for the TM255/455PC 0
HF 10 watt amplifier for 18MHz using a 2SC1969/2SC1944 transistorRF_Amplifier 0
RF Power meter / dummy loadRF 0
HAMCOM (SSTV, RTTY, FAX...) modem using serial audio for TXPC 0
HAMCOM & SoundCard MODEM using serial- or soundcard audioPC 0
SWR bridge covering HF to VHFRF 0
Active bandpass filter with TDA2320AFilter 0
1 Watt audio amp using a TDA7052Amplifiers 0
TM-441 9600bps packet modificationPC 0
1 Watt AM transmitter for the 10 meter band (28MHz)Transmitters 0
12-meterband QRP AM oscillator transmitter using a 2N2219 transistorTransmitters 0
500mW AM transmitter for the 20 meter band (14MHz)Transmitters 0
VHF 6 Meterband RF amplifierRF_Amplifier 0
HF/VHF portable antenna tunerRF 0
90S2313 AVR Robot BoardMicrocontrollerMay 01, 20040
A selection of robotics projectsModelsJun 09, 20020
Digital clock based on 74 series logicTiming 0
LH0032 video amplifierVideoOct 24, 20020
LM359N video amplifierVideoOct 24, 20020
ATmega8 based TNC with GPS and WX supportMicrocontrollerMar 27, 20090
Atmel AVR 90s2313 based POCSAG encoder (ZIP file)MicrocontrollerMar 27, 20090
Atmel 90s2313 based TNCMicrocontrollerMar 27, 20090
ATmega48 based Nixie ClockMicrocontrollerMar 27, 20090
POCSAG encoder/decoder (Zip file)MicrocontrollerJul 10, 20020
Simple alarm with telephone dialler interfaceTelephoneMar 27, 20090
In-circuit electrolytic capacitor checkerTestMar 27, 20090
Logic probe with pulserTestMar 27, 20090
Telephone line simulatorTelephoneMar 05, 20010
Making your own RS-60E3 Remote Control for Canon EOS camerasPhoto 0
Home made PBX / PABXTelephoneJun 17, 20030
Headphone amplifier based on 12AX7 tubesAmplifiers 0
Two nixie display clockTiming 0
Pocket Ignignokt LED displayLED 0
VFD (vacuum flourescent display) clockTiming 0
Single-digit Nixie clockTiming 0
Oscilloscope CRT ClockTiming 0
Weston Voltmeter ClockTiming 0
Using a PC power supply as a benchtop power supplyPC 0
Digibox interface circuit diagramIRAug 09, 20020
Six-channel Mixer and AmplifierAmplifiersJan 31, 20030
Audio Signal SourceAudioOct 30, 20020
Random noise generatorMiscJan 26, 20010
Analog pulse counterMiscAug 12, 20010
Analog opto-isolatorMiscAug 12, 20010
Voltage controlled amplifierAmplifiersAug 12, 20010
Current loop interfaceControlAug 12, 20010
Audio graphic equaliserAudioAug 12, 20010
Intercom preampPreampAug 12, 20010
Electric field & leakage detectorTestAug 12, 20010
Pulse width modulators (PWM)MiscAug 12, 20010
30W ultra-low distortion audio power amplifierAmplifiersJan 22, 20100
Pulse width to voltage converterMiscAug 12, 20010
Ultrasonic remote control & alarm systemAlarmsAug 12, 20010
Grand Cherokee Off-Highway LightsAutomotive 0
Flashing LED circuit using 555 timerLEDJul 03, 20110
Engine control unit schematicsAutomotiveNov 16, 20020
3 Channel Spectrum AnalyzerAudioSep 01, 20090
3 Watt FM Transmitter circuit diagramTransmittersSep 01, 20090
6V to 12V ConverterPower 0
AC Motor Speed ControllerControlSep 01, 20090
Aircraft Radio Communications ReceiverRFSep 01, 20090
Air flow detector using an incandescent lamp to detect airflowMisc 0
Wire Loop Alarm using 4001UBE Quad NOR GateAlarmsSep 01, 20090
Circuit diagram for 8 watt audio ampAmplifiersJan 26, 20010
22 Watt Audio Amplifier using TDA1554 two channel audio amp chipAmplifiersSep 01, 20090
50 Watt Amplifier circuit diagramAmplifiersSep 01, 20090
Fantastic Atom ExpanderLEDSep 01, 20090
Car Alarm Arming Horn Beep CancellerAutomotiveSep 01, 20090
Black LightLightingSep 01, 20090
Portable CD Player Adapter For CarAutomotiveSep 01, 20090
Car Battery ChargerAutomotiveSep 01, 20090
Automatic 12V Lead Acid Battery ChargerPowerSep 01, 20090
LED ChaserLEDSep 01, 20090
Simple Two Speed Contactor DC Motor ControllerControlSep 01, 20090
Digital Keypad Combination LockAlarmsSep 01, 20090
Computer Controlled Frequency Counter/Logic ProbePCSep 01, 20090
Simple Colour OrganMusicSep 01, 20090
7 Segment LED CounterLEDSep 01, 20090
Crystal RadioRFSep 01, 20090
Circuits to computerize your room/housePCSep 01, 20090
TRIAC Light DimmerLightingSep 01, 20090
12VDC Fluorescent Lamp DriverLightingSep 01, 20090
FM Transmitter with range of about 300 feetTransmittersSep 01, 20090
Guitar Fuzz EffectMusicSep 01, 20090
Automatic Headlight Brightness SwitchAutomotiveSep 01, 20090
Solid State Tesla Coil/High Voltage GeneratorPowerSep 01, 20090
Simple Parallel (Printer) Port InterfacePCSep 01, 20090
12V to 120V Inverter circuit diagramPowerSep 01, 20090
Infa-Red Remote ControlIRSep 01, 20090
IR Remote Control JammerIRSep 01, 20090
LASER Power SupplyLaserSep 01, 20090
LASER Transmitter/ReceiverLaserSep 01, 20090
LED ThermometerLEDSep 01, 2009-1
Simple Lie DetectorMiscSep 01, 20090
Light/Dark Detector drives a relayControlSep 01, 20090
Low Voltage AlarmMiscSep 01, 20090
Video Stabilizer/MacroVision RemovalVideoSep 01, 20090
FET Audio MixerAudioSep 01, 20090
Microphone MixerAudioSep 01, 20090
Pulse Width Modulation DC Motor ControllerControlSep 01, 20090
8 Note Tune PlayerMusicSep 01, 20090
Colour (Sound) OrganMusicSep 01, 20090
Ringing Phone Light FlasherTelephoneSep 01, 20090
Phone Busy IndicatorTelephoneSep 01, 20090
FM Telephone BugTelephoneSep 01, 20090
Cut Phone Line DetectorTelephoneSep 01, 20090
Simple Phone Tap CircuitTelephoneSep 01, 20090
Telephone Hold ButtonTelephoneSep 01, 20090
Telephone RecorderTelephoneSep 01, 20090
Simple Polarity TesterTestSep 01, 20090
Water Detector With Sump/Bilge Pump ControllerControlSep 01, 20090
Pine Racecar Victory JudgeGamesSep 01, 20090
Op Amp RadioRF_AmplifierSep 01, 20090
Rain DetectorMiscSep 01, 20090
Time Delay RelayControlSep 01, 20090
Time Delay Relay IIControlSep 01, 20090
Remote Telephone Bell RingerTelephoneSep 01, 20090
Simple Servo Controller using 555 TimerControlSep 01, 20090
Flash Slave TriggerPhotoSep 01, 20090
Stepper Motor Controller using 4027 flip-flop and 4070 XOR gateControlSep 01, 20090
Mono To Stereo Synthesizer / SimulatorAudioSep 01, 20090
Electronic StethoscopeMedicalSep 01, 20090
Strobe lightLightingJan 26, 20010
Adjustable Strobe LightLightingSep 01, 20090
Basic Power SupplyPowerSep 01, 20090
High Current Power SupplyPowerSep 01, 20090
Dual Polarity Power SupplyPowerSep 01, 20090
High Voltage High Current Power SupplyPowerSep 01, 20090
Transformerless Power SupplyPowerSep 01, 20090
Fixed Voltage Power SupplyPowerSep 01, 20090
Wireless Auto TachometerAutomotiveSep 01, 20090
Tone Control using TDA1524A Tone Control ICAudioSep 01, 20090
Simple Transistor OrganMusicSep 01, 20090
Touch Switch using 4011 CMOS NAND Gate ICControlSep 01, 20090
Video Activated RelayVideo 0
Voltage Inverter using 555 TimerPowerSep 01, 20090
Voltage Inverter using LM380 audio amplifier ICPowerSep 01, 20090
Digital Volume Control using DS1669 Digital Pot ICAudioSep 01, 20090
Sound Level MeterAudioSep 01, 20090
89C2051 microcontroller programmerProgrammers 0
JFET Bass PreampPreamp 0
Dual power supplyPowerJan 31, 20030
Magnetic levitation deviceMiscAug 14, 20020
Tesla power receiverMiscJan 06, 20020
Class B series modulatorRF 0
The KD2BD Pacsat ModemPCJul 10, 20020
SHARP palm-top/hand-held to RS232 serial converterPDA 0
1.9 Kilojoule Coil GunMiscNov 16, 20100
20kV Digital High Voltage MeterTestNov 16, 20100
Build your own radio controlled switch from a cordless telephoneTelephoneNov 16, 20100
A spark throwing tesla coil made entirely of garbageMiscNov 16, 20100
Measuring Acceleration Using a PIC Microcontroller (ADXL202 + PIC16F84A)MicrocontrollerJan 09, 20100
PIC serial communications tutorial, includes circuit diagram and PIC16F84 assembler codeMicrocontrollerJan 09, 20100
Eight simple power supplies for your workbench (mainly vacuum tube based)TestApr 10, 20140
Build a Crystal Set (simple AM radio receiver)RFApr 10, 20140
Filter Choke AnalyzerTestApr 10, 20140
Vacuum Tube Grid Leak Detector: Needs an AmplifierTestApr 10, 20140
A Load Box for testing power suppliesTestApr 10, 20140
Low resistance adapter for a DMM (digital multimeter)TestApr 10, 20140
Vacuum Tube Plate Detector: Needs an AmplifierTestApr 10, 20140
Precision Frequency Control for AM Radios - A Frequency Synthesized Local OscillatorRFApr 10, 20140
Miniature SWR / RF power meter circuitTestFeb 15, 20140
Home Brew Compass SensorData AcquisitionApr 27, 20030
Higher Order Analog Butterworth Filter Designs, includes on-line filter calculatorFilterJan 16, 20100
SWTP PR-40 Printer Interface SchematicsPCSep 10, 20060
Interfacing Sony control stick to EmpegGamesJun 09, 20020
Negative voltage generatorPowerAug 12, 20010
Basic Homebuilt Discrete DTL gate circuits (Diode Transistor Logic)Misc 0
Electronic shutter release with ultrasonic remote controlPhoto 0
Lazer Tag Equipment ModificationsMiscMar 23, 20030
A Serial Infrared Remote ControllerPCJan 26, 20010
Driving high-power loads with a microprocessorMicrocontroller 0
Control your camera (Canon DSLR) with your Palm PDAPhoto 0
Simple 10 bit DAC for the Arduino using TLC274 opampArduinoJun 07, 20110
Connect a NTC with a wheatstone bridge to a normal AD-InputData Acquisition 0
IDE interface to a Microchip PIC16F877 microcontrollerMicrocontroller 0
Inexpensive APRS Weather StationMiscAug 14, 20020
1381 solar engineSolarNov 16, 20020
Collection of BEAM robot circuitsModelsSep 01, 20090
Walking robotModelsAug 14, 20020
Computerized Shutter Control of Canon DSLRsPhoto 0
Binary clock using LED matrix to display a binary clock with 6 digits of 4 binary bits eachTiming 0
Making an LM35 temperature recorder (based on PIC12F675) - logs to EEPROMData Acquisition 0
Schematics and C code for a PIC frequency counter operating up to about 50 MHz (7 segment)Test 0
Universal Serial Infrared ReceiverIR 0
Schematics and C code for a 0-5V PIC LCD volt meterTest 0
Driving led display matrix from a PIC microLED 0
Schematics and C code for a PIC frequency counter operating up to about 50 MHz (LCD)Test 0
PIC sonar (ultrasonic) range finding project with seven segment display using PIC microMicrocontroller 0
A Real Time Clock IC (DS1307) project using the PIC microMicrocontroller 0
PIC Serial LCD project - An RS232 serial LCD interface using a standard HD44780 LCDMicrocontroller 0
Stepper motor driver using PIC12F675 that offers serial port command interfaceControl 0
Stepper motor driver using PIC12F675Control 0
Making an LM35 temperature recorder (based on PIC12F675) - serial outputData Acquisition 0
Infrared remote control with intervalometer function for Nikon camerasPhoto 0
IR Remote Control for Nikon cameras, standard versionPhoto 0
Not So Tiny Power Meter - Measures power consumption for entire apartment Not So Tiny Power MeterTestFeb 21, 20130
Accelerometer with microcontroller and displayData Acquisition 0
Using a 555 Timer as an A/D converterData Acquisition 0
Serial cable for Casio QV-200 digital cameraPhoto 0
Locomotive signal braking moduleModels 0
H-Bridge Motor Control with Power MOSFETSControlMar 23, 20150
Connect a Serial LCD Display to Raspberry PiMicrocontrollerMar 23, 20150
DSP-RDF Doppler Radio Direction Finder circuit schematic - complete kit availableRFApr 14, 20110
Sea & Sea TTL (Motormarine II, SX-1000) Flash Interface (underwater photography flash)PhotoSep 25, 20090
White LED Drive CircuitLED 0
Solar Powered Garden Light with PCB layoutSolarFeb 25, 20110
Low Power PLL FM Transmitter based on LMX1601 and Atmel ATtiny2313 or AT90S2313 microcontrollerTransmitters 0
Simplest LED Flasher Circuit using a 2N2222 transistor Simplest LED Flasher Circuit ledLED 0
White LED StroboscopeLEDFeb 25, 20110
4th Order Butterworth filter schematic and calculatorFilterJan 16, 20100
Wave Multiplier for music synthesizersMusicApr 27, 20030
Infinite melody for music synthesizersMusic 0
Nikon Coolpix 950 / 990 / 995 Flash-adapterPhotoSep 25, 20090
Digital clock that receives and displays the time from the Rugby MSF radio transmission (PIC16F877)Timing 0
Remote shutter (or 'cable release') for SLR and DSLR camerasPhoto 0
Transistor based single zone intruder alarmAlarms 0
CMOS single zone intruder alarmAlarms 0
Automatic Intruder Alarm - a simple single-zone burglar alarm circuit based on a 4011 quad NAND gateAlarms 0
Hijack alarmAutomotive 0
Two-component metal detector using a 4093Misc 0
Simple temperature regulated FAN speed controllerControl 0
RS-232 to TTL TranslatorMicrocontroller 0
Car acceleration meterAutomotive 0
Serial port I/O interface using AVR microcontrollerMicrocontroller 0
150W audio amplifier that's cheap to build using TIP142 / TIP147 Darlington power transistorsAmplifiers 0
Infrared motion detector circuitIRNov 13, 20100
LED based transistor tester LED based transistor testerTestOct 05, 20120
Electronic Nicad glow plug driverGamesApr 27, 20030
A Scenix (and PIC) ProgrammerProgrammersJan 26, 20010
Induced voltage sensor delta-peak trigger for coilgunMisc 0
Open loop pulse trigger module for coilgunMisc 0
Optical speed trap to measure the the velocity of the projectileMisc 0
Optical trigger module for coilgunMisc 0
Power MOSFET module for coilgunMisc 0
Three stage induced voltage triggered coilgunMisc 0
Thyristor fired coilgun circuit diagramMisc 0
KITT (from Knight Rider) Car scanner using incandescant lampsAutomotive 0
Magnetic levitation project from Electronics Now, February 1996Misc 0
LNS Technologies Levitator Kit circuit diagramMisc 0
Magnetic levitation project from Popular Electronics, May 1966Misc 0
Magnetic levitation project from Popular Electronics, May 1989Misc 0
Barry's magnetic levitation projectMisc 0
Barry's Coilgun Mark I circuit diagramsMisc 0
Barry's Coilgun Mark II circuit diagransMisc 0
Barry's Coilgun Mark III circuit diagransMisc 0
Barry's Coilgun Mark IV circuit diagransMisc 0
Circuit diagram for Coilgun Pistol Pskov 1100Misc 0
MMC to PIC16F876 circuit diagramMicrocontrollerJun 18, 20030
Three electronic circuit diagrams for thermal controllers including linear and PWM controlControl 0
Circuits for interfacing microcontrollers to a wide number of real-word interfacesMicrocontroller 0
Crest Audio LT Series LT100, LT1500 and LT2000 Schematic Set - class D amplifier (PDF)AmplifiersMar 17, 20100
50O Load and Power MeterRFFeb 21, 20130
Simple Audio Tone Control CircuitAudioFeb 21, 20130
TTL pulse counter/logic probeTest 0
General purpose ISA interface card for PCPC 0
PC ISA Card Random Number GeneratorPC 0
Hardware Random Number Generator with an SX microcontrollerMicrocontroller 0
MIDI cable for Sound Blaster cardsPC 0
PC ISA board containing a Z80 microprocessor (coprocessor card)PC 0
8088 maximum mode SBCMicrocontrollerNov 16, 20020
External antenna for the GPS-38, Magellan 2000, or Eagle Explorer GPS receiversRFMay 01, 20040
EZ80 single board computer schematic (Z80)MicrocontrollerApr 27, 20030
8051 Development System Circuit Board circuit diagramMicrocontrollerJun 20, 20040
Inexpensive infrared reflectometerIR 0
Sallen-Key Low Pass Filter Calculator (handles Butterworth filters, Bessel filters and Chebychev)FilterJan 16, 20100
Multi-User Jeopardy Game (Fastest Finger First)GamesOct 06, 20060
Commodore RF modulatorVideoJan 01, 20030
Shadow activated (or hand wave) motion detectorControl 0
Constant current LED driver circuit using LM334 plus a transistorLEDJul 11, 20120
Laser light output intensity meterLaserOct 06, 20060
175KHz inductive pulse transmitter (PDF)TransmittersJan 26, 20010
175KHz inductive pulse receiver (PDF)RFJan 26, 20010
1-line telephone status indicator powered from a 3V battery (PDF)TelephoneJan 26, 20010
1uS light pulse descriminator plus F to V converter (PDF)MiscJan 26, 20010
1.5V LED flasher B (PDF)LEDJan 26, 20010
200-400 MHz voltage controlled oscillator (PDF)RFJan 26, 2001-1
20MHz VCSEL 3mW laser test circuit (PDF)LaserJan 26, 20010
20MHz laser light detector (PDF)LaserJan 26, 20010
Broadband 2MHz optical fiber receiver (PDF)MiscJan 26, 20010
Line in use indicator that handles two independent phone lines (PDF)TelephoneJan 26, 20010
3KHz low-pass filter plus audio amp (PDF)FilterJan 26, 20010
Low current LED flasher (PDF)LEDJan 26, 20010
Pushbutton one-shot and latch (PDF)ControlJan 26, 20010
Modulated light receiver circuit (PDF)MiscJan 26, 20010
Micro-power 40KHz burst laser diode driver (PDF)LaserJan 26, 20010
40KHz light receiver (PDF)IRJan 26, 20010
40KHz laser burst detector (PDF)LaserJan 26, 20010
40KHz TV-VCR repeater (PDF)IRJan 26, 20010
4-line telephone status indicator that is polarity independent (PDF)TelephoneJan 26, 20010
1uS light pulse receiver plus post amp (MISC)MiscJan 26, 20010
Broadband 5MHz optical fiber receiver (PDF)MiscJan 26, 20010
5W Fluorescent light intensity modulator (PDF)LightingJan 26, 20010
Line powered 60Hz clock generator (PDF)TimingJan 26, 20010
High-speed 75MHz light receiver (PDF)MiscJan 26, 20010
Micro-power pulse generator (PDF)TimingJan 26, 20010
1.5V LED flasher A (PDF)LEDJan 26, 20010
Flashing LED advertising badge (PDF)LEDJan 26, 20010
Flashing LED advertising badge (PDF)LEDNov 17, 20020
Honey Bee counter (PDF)Data AcquisitionJan 26, 20010
Power reminder beeper (PDF)PowerJan 26, 20010
Very loud beeper (PDF)AudioJan 26, 20010
Darkroom camera shutter timerPhotoJan 26, 20010
Capacitance type liquid level measurement (PDF)Data AcquisitionJan 26, 20010
Unplugged power cord alarmPowerJan 26, 20010
Modulated laser diode tester (PDF)LaserJan 26, 20010
Divide by 1.5 counter (PDF)TimingJan 26, 20011
Door knob alarm (PDF)AlarmsJan 26, 20010
Basement doorbell beeper (PDF)MiscJan 26, 20010
Time to dust indicator - battery powered dust indicator (PDF)MiscJan 26, 20010
Charge coupled bi-directional power MOSFET relay (PDF)ControlJan 26, 20010
Finger touch activated switch (PDF)ControlJan 26, 20010
High-output square wave generator (PDF)TimingJan 26, 20010
1W Fluorescent lamp night light (PDF)LightingJan 26, 20010
Water seepage alarm (PDF)AlarmsJan 26, 20010
Machine vibration triggers hour meter (PDF)ControlJan 26, 20010
LASER/LED light output intensity meter (PDF)LaserJan 26, 20010
Solid state relay (PDF)ControlJan 26, 20010
Digital noise generator (PDF)AudioJan 26, 20010
D Flip-flot one-shot circuits (PDF)TimingJan 26, 20010
Low-power optical interrupter (PDF)MiscJan 26, 20010
Micro-power over temperature alarm (PDF)AlarmsJan 26, 20010
Machine power loss beepter (PDF)PowerJan 26, 20010
Simple nitrogen spark generator (PDF)MiscJan 26, 20010
Pulsed LED test circuit (PDF)LEDJan 26, 20010
Low battery voltage flasher (PDF)LEDJan 26, 20010
Video signal edge enhancementVideoJan 26, 20010
Long-period watchdog timerMicrocontrollerJan 26, 20010
Line-powered Xenon flash transmitter (PDF)ControlJan 26, 20010
9V Xenon photoflash controller (PDF)ControlJan 26, 20010
Series Notch Fliter Designer / Calculator (displays circuit diagram after calculation)FilterJan 16, 20100
Cellular Phone calling DetectorTelephone 0
7MHz QRP transmitterTransmittersJul 09, 20020
Tone display systemAudioOct 30, 20020
Tube amplifierAmplifiersAug 14, 20020
Infrared proximity detector based on Microchip PIC12C508 or PIC12C509IRAug 17, 20090
Simple NiCad battery charger using LM317PowerAug 17, 20090
Quickie servo tester for testing servo motors (based on Atmel AT90S2343)TestAug 17, 2009-1
Low cost gyro / accelerometer combo sensorData AcquisitionAug 17, 20090
Analog Filters for Data Conversion (ADC filter)FilterJan 16, 20100
Simple DIY BFO metal detectorMiscJun 27, 20100
Transducer AmplifiersData Acquisition 0
Equivalent circuit and SPICE model of 555 timerTimingApr 11, 20110
ADC Input Driver DIFFERENTIAL to DIFFERENTIALData AcquisitionApr 11, 20110
ADC Input Driver DIFFERENTIAL to SINGLE-ENDEDData AcquisitionApr 11, 20110
ADC Input Driver FULLY DIFFERENTIAL AMPLIFIERData AcquisitionApr 11, 20110
ADC Input Driver SINGLE-ENDED to DIFFERENTIALData AcquisitionApr 11, 20110
ADC Input Driver SINGLE-ENDED to SINGLE-ENDEDData AcquisitionApr 11, 20110
Op-Amp Current Source with Floating Load including SPICE simulationPowerMar 26, 20110
H-Bridge Power Amp circuit diagram and SPICE simulation filesAmplifiersJan 17, 20110
Op Amp Comparator with Hysteresis with SPICE simulationMiscMar 26, 20110
Op Amp Precision Half-wave Rectifier including SPICE simulationMiscMar 26, 20110
Op Amp based PID Controller circuit with SPICE simulationControlMar 26, 20110
Op Amp Triangle-Wave Generator circuit diagram and SPICE simulation filesTimingJan 17, 20110
RC Low-Pass Filter with Op Amp Buffer (single pole filter) with SPICE simulation filesFilterJan 17, 20110
Single-Supply AC Inverting Op Amp amplifier with SPICE simulationMiscMar 26, 20110
Sallen-Key Low-Pass Filter (Double-Pole) with SPICE simulation filesFilterJan 17, 20110
Wien Bridge Oscillator with SPICE simulationTimingMar 26, 20110
Basic Audio Amplifier including a SPICE modelAmplifiersApr 11, 20110
Thermostat node schematicData AcquisitionOct 31, 20020
No-Hum Fan ControllerControlSep 13, 20060
PIC Web Server SchematicMicrocontrollerSep 13, 20060
Micro based PIR to IR remote converterIROct 23, 20020
DIY Microphone Cable for iPod Touch (2nd Gen)PDASep 25, 20090
Hacking the Hot Wheels Radar Gun - includes circuit of analog front endMisc 0
Laser range finder and reflectivity meter for the MARS-96 international space project (PDF)LaserOct 06, 20060
AM/FM/SW active antennaRFJan 26, 20010
Caller ID decoder (requied Postscript file viewer and/or Ordcad schematic capture)TelephoneJan 26, 20010
Clock dividerTimingJan 26, 20010
Clock doublerTimingJan 26, 20010
Headlight reminderAutomotiveJan 26, 20010
Quiz show indicatorGamesJan 26, 20010
Frequency and capacitance meterTestJan 26, 20010
CMOS oscillator using 74C14 inverting Schmitt triggerTimingJan 26, 20010
Adjustable flashing LEDLEDJan 26, 20010
Crystal 32.768KHz CMOS OscillatorTimingJan 26, 20010
Crystal oscillator using a CMOS or HCMOS inverterTimingJan 26, 20010
Video amplifierVideoJan 26, 20010
Condenser microphone hookupAudioJan 26, 20010
Phase shifterAudioJan 26, 20010
Ultrasonic transducer oscillator circuitMiscJan 26, 20010
HV supply: 12VDC in, 12KV outPowerJan 26, 20010
Generating -5VDC from +5VDCPowerJan 26, 20010
IR-related ASCII Schematics V1.00IRAug 27, 20030
Infrared remote transponderIRJan 26, 20010
Cheap 40KHz clock using one gate of a 74C14TimingJan 26, 20010
Astable 40KHz clockTimingJan 26, 20010
Build an Infrared night scopeIRJan 26, 20010
Decoding IR Remote ControlsIRJan 26, 20010
Analog Signal Acquisition for PC Printer PortPCJan 26, 20010
AC switching with TRIAC from TTLControlJan 26, 20010
'Rounding Off' a square waveTimingJan 26, 20010
More accurate PC/AT clockPCJan 26, 20010
Filtering PC bus POWERPowerJan 26, 20010
Control 120VAC relay with TTLControlJan 26, 20010
Build logic gates using discrete partsMiscJan 26, 20010
Driving a relay with a CPUControlJan 26, 20010
Telephone in use lightTelephoneJan 26, 20010
Detecting a telephone ring signalTelephoneJan 26, 20010
Phone In-Use LightTelephoneJan 26, 20010
Phone to audio interface for SSI202 inputTelephoneJan 26, 20010
Phone Off-Hook Indicator using CD4049 hex inverterTelephoneJan 26, 20010
'phone rang' indicator lightTelephoneJan 26, 20010
Phone line to audio interfaceTelephoneJan 26, 20010
Phone in-use (manually activated)TelephoneJan 26, 20010
Telephone Line MonitorTelephoneJan 26, 2001-1
Use old telephones as an intercomTelephoneJan 26, 20011
Phone-In-Use indicatorTelephoneJan 26, 20010
Hold function for TelephoneTelephoneJan 26, 20010
Digital/Standard Phone Line TesterTelephoneJan 26, 20010
IR detectorIRJan 26, 20010
Jacob's LadderMiscJan 26, 20010
100W RMS Amplifier circuit diagramAmplifiersJan 26, 20010
Simple microphone preamplifierPreampJan 26, 20010
PC IR Remote Control HardwareIRAug 27, 20030
Paradoxical Sound SyntheizerAudioJan 26, 20010
Switch debounce using 555TimingJan 26, 20010
RF Sniffer under 0.5MHz to above 500MHzRFJan 26, 20010
Getting power from RS-232 interfacePCJan 26, 20010
Square wave to sine wave converterTimingJan 26, 20010
Small Radio TransmitterTransmittersJan 26, 20010
12 Volt DC Fluorescent Lamp DriverLightingNov 13, 20100
Battery juicer provides a night light from almost flat batteries that would otherwise be dischardedLightingNov 13, 20100
Beam-break Detector For Camera Shutter or Flash ControlPhotoNov 13, 20100
Dual Polarity Unregulated PSU For High-End Audio AmpsPowerNov 13, 20100
High Voltage Converter: 90V From 1.5VPowerNov 13, 20100
Infra-red Light Barrier Using 555IRNov 13, 20100
Infra-Red Sensor/MonitorIRNov 13, 20100
IR On/Off Switch Using a PIC12F629 MicrocontrollerMicrocontrollerNov 13, 20100
Infrared S/PDIF ReceiverIRNov 13, 20100
RC5 Repeater to extend distance of infrared remote controlsIRNov 13, 20100
Super Simple 3 Watt Audio Power Amplifier based on TDA1015AmplifiersNov 13, 20100
Transistor TesterTestNov 13, 20100
VGA to BNC Adapter (Converter)VideoNov 13, 20100
White LED LampLEDNov 13, 20100
Wire Tracer (Receiver)TestNov 13, 20100
Wire Tracer (Transmitter)TestNov 13, 20100
PIC ICDMicrocontrollerOct 23, 20020
Dreamcast interfaceGamesAug 09, 20020
Ultrasonic Range Finder & ImagerData AcquisitionJun 09, 20020
iPod / USB MP3 charger using MC34063 switchmode regulatorPDA 0
Elecraft XG2 receiver test oscillator (PDF)TestSep 13, 20060
Infrared beam barrier / proximity detectorIR 0
Simple electronic buzzerAudio 0
Big Ben sound effects generatorAudio 0
Charge Monitor for 12V lead acid batteryPower 0
Wiper Speed ControlAutomotive 0
PC based Frequency MeterPC 0
7 segment rolling display using PCPC 0
JAM(Just A Minute) Quiz Game CircuitGames 0
Running Message DisplayLED 0
Simple car battery chargerAutomotiveJun 18, 20030
Clap activated remote controlControl 0
Contactless Mains Voltage IndicatorTest 0
Automatic Staircase Light 1Lighting 0
Automatic Staircase Light 2Lighting 0
Clack Clack Electronic BellAudio 0
Electronic Astrologer (decision maker)Games 0
Electronic diceGames 0
Light Operated SwitchControl 0
Mini emergency lightLighting 0
Mini tester: Handles continuity testing, resistor testing, capacitor testing and diode testingTest 0
Musical Electronic BellAudio 0
MW Transmitter can be used as an inter-room radio telephoneTransmitters 0
NiCd Cell ChargerPower 0
Pocket Transmitter that can cover 20 to 25 meters with a telescopic antennaTransmitters 0
Reflex Action GameGames 0
Simple Traffic Light ControllerModels 0
Voice AmplifierAmplifiers 0
Discrete LED Color OrganLED 0
Automatic Plant Irrigation System Circuit for Watering Plants without any Human Interference.MiscDec 07, 20140
BCD to 7 Segment LED Display Decoder CircuitLEDApr 26, 20140
25W MOSFET audio amplifierAmplifiersFeb 21, 20050
50W audio amplifier using ICL8063AmplifiersFeb 21, 20050
Digital volume controlAudioFeb 21, 20050
Electronic attenuatorAudioFeb 21, 20050
Speech recorded using ISD2560AudioFeb 21, 20050
Precision audio millivoltmeterTestFeb 21, 20050
Amplified ear for surveillanceAmplifiersFeb 21, 20050
Flashing / pulsing third brake like for carsAutomotiveFeb 21, 20050
Headlight flasherAutomotiveFeb 21, 20050
Speed alert - wireless portable unitAutomotiveFeb 21, 20050
Parking aid senses distance to rear of vehicleAutomotiveFeb 21, 20050
Automatic headlight brightness switchAutomotiveFeb 21, 20050
Flashing heartGamesFeb 21, 20050
Electronic millipede robotModelsFeb 21, 20050
Circuit diagram of 3V LED chaser using 4017LEDFeb 21, 20050
6V ultra-bright LED chaser using 74HC4017LEDFeb 21, 20050
Smart card programmerProgrammersFeb 21, 20050
Decoder for encoded transmissions in Videocrypt and D2MACVideoFeb 21, 20050
Circuit for gold wafer cardMiscFeb 21, 20050
Jupiter card programemrProgrammersFeb 21, 20050
PIC16F84 based diode testerTestFeb 21, 20050
Nokia 3310 Lcd Thermometer using DS18B20MiscFeb 21, 20050
Lost keys finder using HCF4069MiscFeb 21, 20050
SmartCard PC EmulatorPCFeb 21, 20050
Economy radar detectorAutomotiveFeb 21, 20050
S-Video to RCA adapterVideoFeb 21, 20050
Digital pedometer circuit diagramMedicalFeb 21, 20050
Cellular Phone calling detector (detects RF field)TelephoneFeb 21, 20050
Cuckoo sound generatorAudioFeb 21, 20050
RS-232 Laser TransceiverLaserMay 01, 2004-1
RS-232 laser transceiverLaserFeb 21, 2005-1
Casio dataloggerPDAFeb 21, 20050
Relay interface add-on board for PCPCFeb 21, 20050
8-way relay interface board for PC parallel printer portPCFeb 21, 20050
Stepper motor controller for PC parallel portPCFeb 21, 20050
3-axis stepper motor controller for PC parallel portPCFeb 21, 20050
Optically isolated stepper motor controllerControlFeb 21, 20050
PC based thermometer based on Dallas DS1621PCFeb 21, 20050
VGA to SCART adapterVideoFeb 21, 20050
Basic UPS Power SupplyPowerFeb 21, 20050
Fuse monitor / alarmPowerFeb 21, 20050
4 watt FM transmitter circuit diagramTransmittersFeb 21, 20050
FM transmitter bugTransmittersFeb 21, 20050
Television signal amplifierVideoFeb 21, 20050
Small radio transmitterTransmittersFeb 21, 20050
Electronic Eavesdropping Devices Detector (bug detector)RFFeb 21, 20050
20dB VHF AmplifierRF_AmplifierFeb 21, 20050
30 watt FM linear amplifier circuit diagramRF_AmplifierFeb 21, 20050
AM transmitterTransmittersFeb 21, 20050
2 Transistor FM Voice TransmitterTransmittersFeb 21, 20050
Linear FM 50 watt amplifier with BLY90RF_AmplifierFeb 21, 20050
15 watt FM transmitter circuit schematicTransmittersFeb 21, 20050
Video signal amplifier circuitVideoFeb 21, 20050
CB (27MHz citizens band) receiverRFFeb 21, 20050
Circuit for three axis robot arm based on stepper motors out of 5 1/4" drivesModelsNov 10, 20090
Lightning DetectorMiscFeb 21, 20050
Geomagnetic field detectorMiscFeb 21, 20050
Frost alarmAlarmsFeb 21, 20050
Ultrasonic radar alarmAlarmsFeb 21, 20050
iRDA transceiver to extend IR port range up to 15 metersIRFeb 21, 20050
Remote digital thermometer sends data over AC power lineData AcquisitionFeb 21, 20050
Phone line in use indicatorTelephoneFeb 21, 20051
Telephone music on hold interfaceTelephoneFeb 21, 20050
Soft musical telephone ringerTelephoneFeb 21, 20050
Telephone amplifierTelephoneFeb 21, 20050
Telephone line monitorTelephoneFeb 21, 20050
Cut telephone line detectorTelephoneFeb 21, 20050
FM telephone line bug transmitter (88MHz to 94MHz)TelephoneFeb 21, 20050
Continuity tester using transistorsTestFeb 21, 20050
Latching continuity tester using 4093TestFeb 21, 20050
IR remote control testerIRFeb 21, 20050
Linear Resistance MeterTestFeb 21, 20050
Crystal tester circuit diagramTestFeb 21, 20050
Capacitance meterTestFeb 21, 20050
Digital voltmeter (DVM)TestFeb 21, 20050
Transistor tester using 555 timer and 4027TestFeb 21, 20050
Function generator based upon 8038 waveform generator ICTestFeb 21, 20050
Triangle / Square wave generatorTimingFeb 21, 20050
Picoammeter circuit schematic with 4 ranges using CA3420TestFeb 21, 20050
Beeper to find short circuits (continuity tester)TestFeb 21, 20050
Voltage follower with 1G ohm input resistanceData AcquisitionFeb 21, 20050
Led display digital VoltmeterLEDFeb 21, 20050
MOSFET tester for N-type MOSFET transistorsTestFeb 21, 20050
Inductive meter adapter to measure inductance using a frequency counterTestFeb 21, 20050
Crystal tester that covers a range of 32kHz to 24MHzTestFeb 21, 20050
Oscilloscope testing module (Huntron circuit) that shows Lissajous patternsTestFeb 21, 20050
Voltage monitor with LED indicatorPowerFeb 21, 20050
Logic probe with 7-segment display based on 74LS00 and 74LS47TestFeb 21, 20050
Wireless transmitter for PIR using Holtek HT12ETransmitters 0
OPT301 Laser receiverLaser 0
Heartbeat transducer using infrared LED / detectorMedical 0
ECG amplifier with right leg driveMedical 0
High current regulated power supplyPowerOct 31, 20020
Low-voltage light dimmerLightingNov 17, 20020
Active bandpass filtersFilterNov 01, 20020
Bandpass filtersFilterNov 01, 20020
AM BCB radio receiverRFOct 23, 20020
Regenerative shortwave receiverRFJun 08, 20020
Miniature audio amplifierAmplifiers 0
Optical Heart Rate MonitorMedicalSep 10, 20060
PIC Project #1 - RS232 to I2C InterfaceMicrocontrollerJan 26, 20010
RF front-end for triple conversion GPS receiver (PDF)RFMar 01, 20030
Design and build your own iPod docking stationPDAMay 30, 20070
Various tube crossover circuitsAudioJan 31, 20030
Serial Port A/D-converterData AcquisitionJan 26, 20010
Audio amplifier output relay delayAmplifiersJan 26, 20010
TV/Radio antenna cable galvanic isolatorVideoJan 26, 20010
Audio line isolatorAudioJan 26, 20010
Connect two CD-ROM drives to one soundcardPCJan 26, 20010
Centronics port D/A converters and low-pass filterData AcquisitionJan 26, 20010
4-channel dimmer rack circuit diagramLightingNov 17, 20020
Dynamic microphone to electret microphone inputAudioJan 26, 20010
Fogger smoke machine controllerMiscJan 26, 20010
Headphone driving circuit for soundcardsPCJan 26, 20010
Simple line mixerMusicJan 26, 20010
Simple IR transmitter circuitIRJan 26, 20010
Simple infra-red detectorIRJan 26, 20010
Experimental laser data linkLaserJan 26, 20010
Simple light sensor adapter for oscilloscopeTestJan 26, 20010
Line level signal to microphone input adapterAudioJan 26, 20010
Simple two line output combinerAudioJan 26, 20010
Adjustable power supply using LM317PowerJan 26, 20010
Get power out of PC parallel portPCJan 26, 20010
Simple microphone preamplifierPreampJan 26, 20010
Electret microphone powering circuitsAudioJan 26, 20010
Simple MIDI testerMusicJan 26, 20010
Null Printer AdapterPCJan 26, 20010
PC speaker volume control circuitPCJan 26, 20010
Use amplifier phono input as line level inputAmplifiersJan 26, 20010
How to get power from PC to your circuitsPCJan 26, 20010
Simple +5V power supply circuitPowerJan 26, 20010
RS-232 surge protectionPCJan 26, 20010
Simple RS-232 serial port buffer circuitPCJan 26, 20010
Get power out of PC RS-232 portPCJan 26, 20010
Sound Blaster Microphone PreamplifierPCJan 26, 20010
Sega 3D glasses interface circuit diagramsPCJan 26, 20010
0-10V control for RC servosModelsJan 26, 20010
Speaker signals to line level inputsAudioJan 26, 20010
S-video to composite video adapterVideoJan 26, 20010
TDR cable reflection tester (Time Domain Reflectometer)TestSep 21, 20060
Telephone privacy adapterTelephoneJan 26, 20010
Telephone ringing circuitsTelephoneJan 26, 20010
Simple circuit to connect telephone equipment to audio mixerTelephoneJan 26, 20010
VGA to RGB + composite sync -converterVideo 0
VGA to TV converterVideoJan 26, 20010
VGA to PAL and NTSC converterVideoJan 26, 20010
A-weighting filter from an old Ampex service manualFilterMay 07, 20100
Convert Atari-style joystick to PC joystick portPCJan 26, 20010
Fake Joystick circuitPCJan 26, 20010
Using the joystick port as general purpose inputPCJan 26, 20010
Connect other circuits to PC joystick portPCJan 26, 20010
HeNe laser power supplyLaserJun 09, 20020
Video/Audio Wireless TransmitterVideoOct 23, 20020
Using an ADXL330 accelerometer with an AVR microcontrollerMicrocontrollerJan 09, 20100
Peggy - A Light Emitting Pegboard DisplayLED 0
LPG leakage alarm using SEN-1327 gas sensor module (detects 4 other dangerous gases)AlarmsJul 17, 20120
Build your own iRDA SIR Transceiver (Dongle) using MCP2120PCAug 27, 20030
Programmable Optical Slave Flash Trigger for Digital Cameras using PIC12F675Photo 0
7MHz SSB TransceiverRFMay 01, 20040
Homebuilt MP3 PlayerMusic 0
5 Zone Alarm Circuit circuit diagramAlarms 0
Strain gauge sensor interfaceData Acquisition 0
Ultrasonic Distance Measurer based on Freescale MC9RS08KA2 (PDF)Microcontroller 0
Model 2030 XRAY monitor instruction manual including schematics (PDF)MedicalSep 13, 20060
Rangefinder with Fast Multiple Range CapabilityLaserOct 06, 20060
Laser diode transmitter RF sectionLaser 0
DC Fault Protection Circuit for Audio AmplifiersAmplifiersJan 29, 20100
Soft Power On Tester for AmplifiersTestJan 29, 20100
Zonk Machine and Treble BoosterMusicJan 31, 20030
One 9V battery gives +18, +25, +33VPowerJul 24, 20020
+9V *and* -9V from one batteryPowerJul 24, 20020
Pulse Induction Metal Detector part 1 (PDF)MiscJun 27, 20100
Pulse Induction Metal Detector part 2 (PDF)MiscJun 27, 20100
Lightning shutter trigger for a camera using an ArduinoArduinoNov 13, 20100
Camera Axe open hardware and open software project for camera triggeringPhotoNov 13, 20100
Direction sensing infrared motion detector using PIR (PDF)IR 0
Universal telephone holdTelephoneJan 26, 20010
Video switcher - run up to four cameras into one video monitor (PDF)Video 0
Talking phone dial monitor (PDF)TelephoneJan 26, 20010
Stepper motor positionerControlJan 26, 20010
Infrared Motion Detector using a PIR sensor (PDF)IR 0
Pyroelectric Infrared (PIR) SensorIRJan 26, 20010
Mobile APRS / GPS tracking systemMiscMay 01, 20040
GPS receiver support kitMiscMay 01, 20040
GPS receiver (Gamin, Eagle etc) to PC interface cablesPCMar 23, 20030
Heart of LEDsLEDOct 23, 20020
Christmas StarLEDOct 23, 20020
Christmas treeLEDOct 23, 20020
Simple Skype VoIP analog adapterTelephoneSep 10, 20060
Brain-Wave MachineMedicalNov 27, 20020
Cranial Electrotherapy Stimulation (CES) circuit diagramMedical 0
Lie detectorMedicalOct 30, 20020
Simple lie detectorMedicalOct 30, 20020
Furby reverse-engineered circuitGamesApr 27, 20030
Circuit and Arduino sketch for interfacing to a DS18B20 1-wire temperature sensorArduinoJul 21, 20130
Simple MPPT (maximum power point tracker) for photovoltaic arrays (PDF)SolarMar 09, 20120
TXTVb - 70cm ATV Test Generator (PDF)Test 0
BCD readout frequency counterTestAug 18, 20090
Binary clock circuit diagramTimingAug 18, 20090
Experimental DDS frequency synthesizer uses the AD9851TimingOct 08, 20090
Dekatron circuit diagram - device used for dividing by 10 during the valve eraMiscOct 25, 20090
Circuit diagrams for making logic gates from discrete componentsMiscOct 25, 20090
Simple intercom circuit diagramTelephoneOct 25, 20090
LCD Frequency CounterTestAug 18, 20090
Circuit for remote lighting controller using a 433MHz AM keyfob transmitterLightingOct 25, 20090
LED matrix clock circuit diagramTimingAug 18, 20090
Miniscope - simple all-valve 1-inch CRT oscilloscopeTestOct 25, 20090
Positive Feedback Circuit for Isometric Muscle ExperimentsMedicalNov 05, 20090
Z80 Computer circuit diagramPCAug 18, 20090
Giant nixie clock circuit diagramTimingAug 18, 20090
Panel-mounting clock circuit diagramTimingAug 18, 20090
Basic 78xx series regulator mains power supply circuit diagramPowerOct 25, 20090
Simple QRSS callsign keyer based on an Atmega AVR programmed in CProgrammersNov 05, 20090
Panel Mounting Radio Frequency CounterTestAug 18, 20090
Giant T-shaped LED matrix display board for financial applications containing 275 8x8 LED modulesLEDOct 25, 20090
Simple Frequency CounterTestAug 18, 20090
Sidereal clock project with circuit diagramsTimingAug 18, 20090
Heathkit signal generator user manual and circuit diagramTestOct 25, 20090
Spectrum analyzer Mk 1TestAug 18, 20090
Spectrum analyzer Mk 2TestAug 18, 20090
TinyScope - simple all-valve 1-inch CRT oscilloscopeTestOct 25, 20090
Asynchronous 40-bit TTL CPUMicrocontrollerAug 18, 20090
USB charger circuit diagramPowerAug 18, 20090
Z80 controlled Viscometer projectTestAug 18, 20090
Wind speed loggerData AcquisitionOct 25, 20090
Wind speed logger Mk2Data AcquisitionOct 25, 20090
The Great Z80 Computer ProjectPCAug 18, 20090
AVR-Based Serial Port IR ReceiverMicrocontrollerOct 23, 20020
Ethernet interface for Commodore 64 computerPC 0
i2c-tiny-usb, a simple i2c interface for the usb portPC 0
LCD2USB, cheap open source text LCD interfacePC 0
LEDMATRIX, a 80x32 pixel DIY LED matrix displayLED 0
Interfacing ADXL202 accelerometer to PalmPilotPDAApr 27, 20030
SPI2CF, a fast and efficient WLAN interface for the AVRMicrocontroller 0
TiltStick, a motion sensing device (USB interface to accelerometer)PC 0
Building an Infrared Transmitter for Your PCPC 0
Minimum Theremin Kit SchematicAudioSep 13, 20060
FM radio for a PIC (uses TDA7000 IC which is now obsolete)PCSep 08, 20090
Lightning detector circuit diagramMiscSep 08, 20090
Build an iButton electronic lock based around a AT91C2051 microcontroller (includes ASM source code)AlarmsNov 10, 20090
AM receiver circuit diagramRFSep 08, 20090
Using an Apple II+ Computer as a Flash Intervalometer (PDF)PhotoMay 09, 20100
Heathkit Groundtrack GR-1290 VLF metal detector circuit diagram and detector coil construction notesMiscJun 27, 20100
White's Surfmaster PI (pulse induction) metal detector schematic diagramMiscJun 27, 20100
Ultrasonic Radar Alarm Circuit DiagramAlarms 0
10 tricks for interfacing to the PIC16C508MicrocontrollerNov 05, 20090
Circuit to connect a rotary encoder to a Arduino UNOArduinoJul 21, 20130
555 Based Simple Servo ControllerControl 0
Fluorescent Tube "Strip light" DriverLighting 0
Field Strength Meter (FSM) covers 2Mhz - 1Ghz with peak reception at 3-200MhzTest 0
Simple Function Generator using TL084 or other opampTiming 0
H Bridge controller for DC motorsControl 0
Advanced High Voltage PSU circuitPower 0
Authentic Looking Knight Rider Led ProjectAutomotive 0
6 Pole ElectroMagnet Motor (aka Simple Brushless motor)Misc 0
88-108Mhz FM Radio Transmitter with 3 transistor stagesTransmitters 0
Serial servo controller for interfacing hobby servos via RS232 to a PCPC 0
Solid State Tesla Coil and Wireless PowerMisc 0
Tesla coil construction projectMisc 0
12 Vdc - 120 Vac Inverter SchematicPowerJan 01, 20030
POV Persistence Of Vision 2 x 32 LED displayLED 0
Vareity of circuits for interfacing to/from TTL logicMisc 0
Victoria TAFE programmer (based on AT89C2051)ProgrammersJan 31, 20030
JDM programmer circuit diagramProgrammersJan 31, 20030
PIC micro programmer circuit diagramProgrammersJan 31, 20030
Dinsmore 1490 digital compassMiscNov 29, 20020
Geiger counter circuit diagramMiscNov 29, 20020
Speech recognition using HM2007MicrocontrollerNov 29, 20020
PIC microcontroller servo motor interfaceMicrocontrollerNov 29, 20020
PIC micro multiple servo motor interfaceMicrocontrollerNov 29, 20020
Electric field disturbance monitorMiscJan 26, 20010
3 KHz low pass filter plus audio amplifier circuit diagramFilterApr 14, 20100
Micropower pulse generator (PDF)TimingJan 26, 20010
Inexpensive seismometer projectMiscDec 15, 20020
Constant current LED driver circuit using an NPN transistor to control an N-channel MOSFETLEDJul 11, 20120
Simple 430MHz band FM transmitter uses only 2 FETtransistorsTransmitters 0
110mW emitter follower audio power amplifierAmplifiersJan 22, 20100
AM transmitter using no power supplyTransmitters 0
NE555 drives a speakes: Pulse Width Modulation AmplifierAmplifiersMar 30, 20100
UHF signal generatorTest 0
VHF signal generatorTest 0
Judge Dredd pinball locking ring modificationGames 0
PIC micro frame grabber (TDA8708)VideoFeb 01, 20030
Digitally Addressable DALI Dimming Ballast (PDF)LightingDec 27, 20040
New and Improved Sound Card Packet Interface tested with PSK31 and APRSPCOct 27, 20090
Home security projectAlarmsNov 17, 20020
PC Controlled RC car construction projectModels 0
DC Motor Controller using 74 series chipsControl 0
Pulse Circuits for Infrared LEDs and Visible Diode LasersLaserAug 04, 20120
Pulse Circuits for Infrared LEDs and Visible Diode LasersLaserMar 04, 20101
LED Modulation Circuits including 5MHz and 50MHz versionsLEDApr 17, 20110
Measuring the speed of light with an infrared LED / photodiode (TDOA)IRJun 13, 20110
Canon DSLR cable shutter release usin 4N25 for optical isolationPhotoSep 25, 20090
Spatial Distortion Reduction Headphone AmpAmplifiersJan 31, 20030
Simple GPS Stabilised 10 MHz OscillatorTiming 1
Sanyo 20EZ monitor circuit diagramPCMar 18, 20030
Burger Time Arcade Game circuit diagram (PDF)GamesMar 17, 20090
Dig Dug Arcade Game (800k ZIP)GamesMar 18, 20030
Frogger Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Frogger Sound/ROM - FROGSND Arcade game circuit diagram (PDF)GamesMar 30, 20140
Gyrus Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Junior Pacman Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Ladybug Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Mappy Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Moon Cresta Arcade circuit diagram (PDF)GamesMar 18, 20030
Mr.Do Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Pengo Arcade Game circuit diagram (PDF)GamesMar 18, 20030
PacLand Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Q*Bert Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Qix Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Scramble Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Time Pilot'84 Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Xevious Arcade Game circuit diagram (PDF)GamesMar 18, 20030
Robotic microcontroller boardModelsJan 31, 20030
Single to 3-phase power conversionPower 0
Low noise PIN diode laser receiver circuitLaser 0
Circuits for biasing and modulating laser diodesLaser 0
inexpensive high speed microwave data link using an Alpha Gunnplexer for 10 Mbps data rateRF 0
18 dB LT1253 DDS amplifier circuit diagramRF_Amplifier 0
23 dB Bipolar DDS AmplifierRF_Amplifier 0
15M CW Transceiver designRF 0
20 Meter CW TransceiverRF 0
30 Meter, Discrete Component CW Transceiver Built Manhattan-styleRF 0
K8IQY's Original 2N2/40 CW Transceiver RigRF 0
40 to 6 Meter "No Tune" TransverterRF 0
SW30+ 30 Meter CW TransceiverRF 0
-20 dB Couplers for use with a with a spectrum analyzer or other sensitive detectorTest 0
-20 dBm, 14.060 MHz Precision Signal SourceTest 0
RC Audio OscillatorAudio 0
Precision VXO for Crystal Characterization & MatchingTest 0
Return Loss BridgeTest 0
Lossless portable digital audio player using the Microchip PIC32Music 0
Water system controller (PDF)Control 0
GPS LCD Display ProjectMicrocontrollerJul 24, 20020
PIC16F84 LED chaserMicrocontrollerNov 17, 20020
PIC micro LED projectsMicrocontrollerJun 18, 20030
PS/2 keyboard keystroke logger based on Atmel 89C2051MicrocontrollerJun 20, 20040
Aurora Alarm: Automated Detection System for the Northern LightsMisc 0
6502 Microprocessor KitMicrocontrollerMay 19, 20150
68k Single Board ComputerMicrocontrollerMay 19, 20150
AT89C4051based digital clock with 16x2 LCDMicrocontrollerMay 19, 20150
Digital Clock with Alarm Using DS1307MicrocontrollerMay 19, 20150
Realtime Clock with LCD based on an Atmel AT89C4051MicrocontrollerApr 22, 20140
Simple RS232C Level Converter using TransistorsPCJun 19, 20110
AVR910 - AVR ProgrammerProgrammersJun 07, 20110
AVR thermometer using AT90S2313 and DS1820MicrocontrollerMay 19, 20150
HC-11 Evaluation BoardMicrocontrollerMay 19, 20150
SBC built with 16-bit Intel Embedded Microprocessor, 80C186EBMicrocontrollerMay 19, 20150
16-bit microprocessor learning board based on Intel 80C188EB Embedded MicroprocessorMicrocontrollerMay 19, 20150
C-52 Evaluation Board based on a 89C52MicrocontrollerMay 19, 20150
C-52 Evaluation Board V2.0 based on a 89C52MicrocontrollerMay 19, 20150
C-52 Evaluation Board Robot ControllerMicrocontrollerMay 19, 20150
Cheap Loader Cable of Asim's ISP for 89S51 89S52MicrocontrollerMay 19, 20150
Data Acquisition& Logging System UsingAT89c51Data AcquisitionMay 19, 20150
DC Voltage and Current SourcePowerMay 19, 20150
Student DC power supplyPowerJun 19, 20110
Electronic distance meter based on Motorola 68HC908QY4MicrocontrollerJun 20, 20040
MCS-51 Propeller LEDLEDMay 19, 20150
Easy-Downloader V1.1 for ATMEL 89C2051/4051MicrocontrollerMay 19, 20150
Easy-Downloader V1.1 with SDCCMicrocontrollerMay 19, 20150
Atmel AVR ATMega 8535/16/32 and AT89S5x family learning kitMicrocontrollerJun 07, 20110
Make your own PIC ProgrammerProgrammersMay 19, 20150
F84 low-cost and very simple serial programmer for a PIC16F84 Microchip Flash MicrocontrollerProgrammersMay 19, 20150
F84 simple real-time controller with PIC16F84 running at low powerMicrocontrollerMay 19, 20150
Fan timer based on Motorola 68HC908QT2MicrocontrollerJun 20, 20040
Isolated RS232C for PIC16F84 or other microcontrollersMicrocontrollerJun 19, 20110
ISP Flash Microcontroller Programmer for Atmel DevicesProgrammersMay 19, 20150
Atmel AVR and 8051 series ISP programmerProgrammersJun 20, 20040
Interfacing Alphanumeric LCD to Parallel Port using Visual Basic 6.0PCMay 19, 20150
Easy debugging serial terminal with LCD displayMicrocontrollerMay 19, 20150
SPI Interface Big 7-Seg LEDLEDJun 19, 20110
AT89C2051 line-follower robotMicrocontrollerJan 26, 20010
Interface LTC1298 with Standard Parallel PortPCMay 19, 20150
RS232C level converters based on Maxim MAX232 or Dallas DS275PCMay 19, 20150
M-Logger V1.0 based on PIC18F46J11 microcontroller and a DS1820 temperature sensorMicrocontrollerMay 19, 20150
MTK-85 8085 Microprocessor Training KitMicrocontrollerJun 07, 20110
Isolated RS422 adapter for PC serial portPCJun 19, 20110
Simple and easy build RS232C-RS485 converterPCJun 19, 20110
Circuit that provides a short circuit protected power supply from PC 12V supply voltage.PowerMay 19, 20150
Digital pH MeterTestMay 19, 20150
In-Circuit PIC Loader (parallel port based)MicrocontrollerMay 19, 20150
PIC18F2550 Project BoardMicrocontrollerMay 19, 20150
PIC Harmonic Distortion Meter for measuring the quality of AC supplyTestMay 19, 20150
Data Acquisition System using ATmega8Data AcquisitionJun 07, 20110
Atmel 89C2051prototyping boardMicrocontrollerApr 22, 20140
4-Channel Pt100 ThermometerData AcquisitionMay 19, 20150
Pyranometer to Current ConverterData AcquisitionJun 19, 20110
PC Power Reboot Circuit for ATX power suppliesPCJun 19, 20110
AVR Line Following RobotModelsMay 19, 20150
Isolated Full Duplex RS232C Interface for a PCPCJun 19, 20110
RS232 Expander - Expands PC's COM port from COM1 to COM1/1 and COM1/2. No active partsPCMay 19, 20150
Miniature Real-time Controller based on a 89C2051ControlApr 22, 20140
S-52 Simple Learning Board using Atmel AT89S52MicrocontrollerMay 19, 20150
Night light saver (PIC12C508)MicrocontrollerJun 09, 20020
Night Light Saver V5.0 using a AT89C2051 and TRIACLightingApr 22, 20140
Night Light Saver V6LightingApr 22, 20140
Cheap oscilloscope and sensor probes for physics experiment in schoolTestMay 19, 20150
Circuit for soft start module for induction motorControlJun 19, 20110
Solar Energy MeterSolarMay 19, 20150
Solar Recorder for measuring daily insolationSolarMay 19, 20150
Solar station for insolation measurement with Ubuntu server 7.10 and a 24-bit Delta-sigma converterSolarJun 07, 20110
SPI Flash Microcontroller Programmer for 8051 and AVR series devicesProgrammersMay 19, 20150
Java Bot - Simple line follower robotModelsJun 19, 20110
Atmel 89S and AVR Programmer (STK200)ProgrammersJun 07, 20110
Thermistor Thermometer using 12-bit ADC, 89S52 and LED displayMicrocontrollerMay 19, 20150
Thermistor Thermometer: LCD versionMicrocontrollerMay 19, 20150
DigiThermo - a laboratory instrument that measures time and temperatureTestApr 22, 20140
Time switch with two optotriacs to control resistive AC loads directlyControlMay 19, 20150
Tiny 2313 Project Development BoardMicrocontrollerJun 07, 20110
USB and GLCD expansion board for 8051 SBCMicrocontrollerJun 20, 20040
USB Easy-Downloader V5.0 for 89S52 and SST89E516RD chips with USB port connectionMicrocontrollerMay 19, 20150
+/-5A Voltage Controlled Current SourcePowerMay 19, 20150
AT89C2051 Programmer using Linux terminalProgrammersApr 22, 20140
xTimer V1.0 a 4-Channel Timer based on a 89C4051 + MAX7219 display driverTimingApr 22, 20140
xTimer using CMOS shift register 4094 for driving 7-segment LED directlyTimingApr 22, 20140
Z80 Microprocessor KitMicrocontrollerMay 19, 20150
FAN Thermostat controlled by IR remote controllerIRMay 19, 20150
Breadboard supply - very low dropout adjustable power supplyPowerOct 12, 20090
Bedazzler: Do-it-yourself Handheld LED-Incapacitator (non-lethal weapon)LEDOct 12, 20090
Dimmable Li-Ion Halogen Bike LightLightingOct 12, 20090
Solderless Breadboard Arduino Clone for Arduino prototypingArduinoOct 12, 20090
Digg Button KitMiscOct 12, 20090
Drawdio - A very simple musical synthesizer that uses the conductive properties of pencil graphiteMusicOct 12, 20090
Ethernet shield for Arduino (Xport)ArduinoOct 12, 20090
Fuzebox - open source 8-bit game console based on Atmel ATmega644-20PUGamesOct 12, 20090
GPS / Datalogging shield for Arduino microcontrollerArduinoOct 12, 20090
Ice Tube Clock - Vacuum fluorescent display (VFD) clockTimingOct 12, 20090
Real-world MIDI interface platform project including circuit diagram and PCB design filesMusicOct 12, 20090
Persistance of vision (POV) toyGamesOct 12, 20090
Portable MP3 music playerMusicOct 12, 20090
Small battery-powered USB charger including circuit diagram and PCB layoutPowerOct 12, 20090
Arduino based controller interface for servo motors, stepper motors and DC motorsArduinoOct 12, 20090
Arduino microcontroller prototyping systemArduinoOct 12, 20090
SIM card reader circuit diagramMiscOct 12, 20090
Persistence of Vision Display for BikesLEDOct 12, 20090
High power infrared remote control to turn off television sets from a distanceIROct 12, 20090
USBtinyISP - AVR programmer & SPI interface projectProgrammersOct 12, 20090
Wave Bubble self-tuning portable RF jammerRF 0
Wave Bubble - A design for a self-tuning portable RF jammerRFOct 12, 20090
Wave (Audio) shield for Arduino microcontrollerArduinoOct 12, 20090
Bassline synthesizer/sequencerMusicOct 12, 20090
YBox2 - DIY networked set-top box that connects to a TV to deliver Internet contentVideoOct 12, 20090
Mini-Beacon - miniature programmable LED Flasher that is based around a PIC12F629 microcontrollerLED 0
Subwoofer Filter, Gainer, Auto Power SystemAudio 0
PC-based ISA data acquisition and control boardPCSep 13, 20060
Circuit for driving a liquid crystal (LCD) shutter to simply pass or block lightMiscDec 21, 20090
Linux Infra-red Remote Control (LIRC)PCApr 12, 20010
Simple home made ADS-B receiver that takes IF from a modified receiverRFOct 04, 20100
Very Simple ADSB Receiver using a TV tunder to allow reception of aircraft transpondersRFOct 04, 20100
115200 RS232 QPSK RF modem projectRFOct 04, 20100
Build your own MARES dive computer IRIS interface for RS232PCOct 04, 20100
3.3V / 5V Regulated Power Supply CircuitPowerJul 03, 20110
Acceleration Sensing - gesture controllers for robotic musical instrumentsModelsJan 09, 20100
Distance Sensing - devices for wireless distance and position determinationModelsJan 09, 20100
Doppler radar based gesture measurement system capable of delivering positional informationModelsJan 09, 20100
Infrared Body SensingIRJan 09, 20100
Homebuilt RS232 LCD InterfacePCJun 18, 20030
Lie detectorMisc 0
Project to capture infrared remote control signals and play them back, based on Atmel ATMEGA48 microIRJan 17, 20100
MIDI Controller FootpedalMusicAug 14, 20020
DIY Serial MIDI Interface (80C51/80C31 Version)MusicAug 14, 20020
Homemade Serial to Nokia MBus Interface on a PCB, without using Zener diodesPC 0
Microcontroller sensor and actuator interfacesMicrocontrollerApr 27, 20030
Hi-Fi Preamp with remote-control and other advanced featuresPreamp 0
Actvie speaker based on a dual op-amp (LM833) and TDA2030 power ampAmplifiers 0
4 channel power amplifier with bi-amping and bridging optionsAmplifiers 0
Amplifier based on LM4780 including a thermal shutdown featureAmplifiers 0
Lead-Acid Battery MonitorPower 0
Complete Design for Giant 8-foot LCD Counter (Zip file)MicrocontrollerMar 27, 20090
PIC12C509 logic gate replacement for nitrogen filler (ZIP file)MicrocontrollerMar 01, 20030
PIC demo boardMicrocontrollerOct 31, 20020
Disco light controller (ZIP file)LightingMar 01, 20030
DS1821 programmable thermostatControlMar 01, 20030
PIC12C509 Gym Timer (ZIP file)MicrocontrollerMar 01, 20030
PIC LCD and Keypad driverMicrocontrollerOct 31, 20020
PIC12C508 Phase Controller for 2kW heater (ZIP file)MicrocontrollerMar 01, 20030
PIC16F84 TRIAC / IGBT brightness phase controllerMicrocontrollerMar 01, 20030
PIC16F84 pulse monitor with date/time output (ZIP)MicrocontrollerMar 01, 20030
Simple metal detector based on a PIC12F683 microcontrollerMiscJun 27, 20100
Three component bat detector based on a PIC12F683 microcontrollerMiscJun 27, 20100
Mini oscilloscope based on PIC18F4620 and standard 16x2 text LCD display moduleTestJun 27, 20100
PIC based touch clock that demonstrates interfacing a PIC microcontroller to an LCD touch panelMicrocontrollerJun 27, 20100
Pico OSD, a PIC video superimposerVideoJun 27, 20100
A PIC16F84A Alarm ClockMicrocontrollerJun 27, 20100
PIC16F877A Thermometer with MCP9700A sensorData AcquisitionJun 27, 20100
A Voice Controlled LED Light Show using a VRStampMicrocontrollerJun 27, 20100
PIC PAL Video Library including source code and circuit schematicsVideoJun 27, 20100
Cheap Ultrasonic Range Finder based on a PIC microcontrollerMicrocontrollerJun 27, 20100
Cheap Ultrasonic Range Finder based on PIC16F877A with a 8MHz crystalMicrocontroller 0
A PIC16F819 Dymoclock (also demonstrates interfacing 30 LEDs to a PIC using only six I/O pins)MicrocontrollerJun 27, 20100
MemoSound game based on a PIC16F84AGamesJun 27, 20100
EasyPic2 with on-board Ethernet AdapterMicrocontrollerJun 27, 20100
Automatic LED display dimmer using a LED as a light sensorLEDJun 27, 20100
DCF-77 PIC LED clock (DCF77 is the name of a German radio station on 77.5 KHz)TimingJun 27, 20100
DCF77 PIC16F84A Single-Nixie clock (DCF77 is the name of a German radio station on 77.5 KHz)TimingJun 27, 20100
Yaesu FT-736R doppler compensationRFAug 14, 20020
AI-1 ("All-in-one") Remote - photographic accessory that you can buildPhoto 0
HeadBanger Headphone AmpAmplifiersJan 26, 20010
Pad launch controller for model rocketsModelsJun 17, 20030
Stage center reverb unit circuit schematicMusicApr 14, 20100
Custom USB tyre pressure monitoring systemAutomotive 0
Simple flashing light circuitModelsJan 26, 20010
Simple flashing light circuitModelsJan 26, 20010
A dual alternating flashing light circuitModelsJan 26, 20010