Click any of the quicklinks below to access area of interest:

Alarms and security related schematics
Audio power amplifiers
Audio preamplifiers
Automative and car related schematics
Data acquisition and data logging schematics
Filter schematics
Games and fun stuff (schematics)
Infrared based schematics
Laser related power supplies and data transmission
LED related schematics
Lighting schematics
Medical and health related schematics
Microcontroller based schematics
Misc audio (also see Music, Amplifiers, Preamp)
Miscellaneous schematics
Model and remote control schematics
Motor and general control schematics
Music related schematics (also see Audio)
PC related schematics
PDA interfaces and related schematics
Power supplies and control schematics
Radio-frequency schematics (also see Transmitters)
Solar-powered schematics
Telephone and intercom related schematics
Test equipment schematics
Timing, oscillators etc. (schematics)
MISC. SCHEMATICS
Transmitter schematics
Video related schematics

Alarms and security related schematics

• Proximity alarm
  
• Electronic lock
  
• Electronic door codelock (PIC16F84)
  
• Moisture alarm
  
• Fridge door alarm
  
• Ultrasonic remote control & alarm system
  
• Wire loop alarm
  
• Digital entry lock
  
• Proximity switch
  
• Toxic Gas Detector
  
• Door knob alarm (PDF)
  
• Water seepage alarm (PDF)
  
• Micro-power over temperature alarm (PDF)
  
• Personal silent alarm system
  
• Active IR motion detector
  
• A Basic RF Transmitter for PIR Sensors
  
• PIR motion detector
  
• Simple alarm system
  
• Automatic door opener using PIC12C508
  
• Home security project
  
• 5 Zone alarm circuit
  
• Miniature loop alarm
  
• Novel Buzzer
  
• Gate alarm circuit
  
• Modular Burglar Alarm
  
• Motorcycle alarm
  
• Enhanced 5 Digit Alarm Keypad
  
• Enhanced 4 Digit Alarm Keypad
  
• RF Alarm
  
• Single Zone Alarm
  
• Water Activated Alarm
  
• Water level alarm
  
• Perimeter monitor
  
• Digital combination lock
  
• Alarm control keypad
  
• Almost Ultrasonic Motion Sensor
  
• Touch activated alarm system
  
• Combination Lock (PIC16F84)
  
• Low power RFID transponder
  

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  CYBER MAX FM 15W
  Meet the Cyber MAX FM; professional rack mount transmitter, backlit LCD display, digital stereo encoder, power regulation from 0 to max, stylish enclosure. Comes with a built-in power supply and requires absolutely no tuning, making this unit very easy to use!!
  
  
  Audio power amplifier schematics

• Two transistor audio amplifier
  
• Personal stereo audio amp
  
• Headphone amplifier
  
• 1.5W Audio amplifier
  
• Low-level audio amp
  
• 10W amplifier
  
• 80W amplifier
  
• LM383 12V Amplifier
  
• 100W Amplifier
  
• 18W Audio amplifier
  
• 25W MOSFET amplifier
  
• Headphone amplifier
  
• Portable headphone amplifier
  
• 2W amplifier
  
• 4W amplifier
  
• 8 watt audio amp
  
• 20W Amplifier
  
• 50W Amplifier
  
• 100W Audio amplifier
  
• 100W RMS Amplifier
  
• 2-Channel Power Amplifier
  
• Push-Pull Class A Amp using type 5687 dual triodes
  
• Push-Pull Class A 2A3 Stereo Amp
  
• Single Ended Class A2 SV811-10 Stereo Amp
  
• Audio amplifier output relay delay
  
• Spatial Distortion Reduction Headphone Amp
  
• HeadBanger Headphone Amp
  
• 2W Amplifier
  
• TDA2030 8 Watt amplifier
  
• Headphone distribution amp
  
• Headphone monitor amp
  
• 50W audio power amplifier
  
• Bi-Directional 2.4 GHz One Watt Amplifier
  
• Bi-Directional 900Mhz One Watt Amplifier
  
• 20 Watt GaAaFET Power on 2.3 GHz
  
• 1 Watt 2.3 GHz RF Amplifier Using a MRF2001
  
• 2.3 GHz Power Amplifiers
  
• 2304 and 3456 MHz Power Amplifiers
  
• High quality exponential VCA
  
• 16 Watt amplifier
  
• 8 Watt amplifier
  
• Power amp schematic (PDF)
  
• 20 Watt Class-A Power Amplifier
  
• El-Cheapo - A Really Simple Power Amplifier
  
• Single Chip 50 Watt / 8 Ohm Power Amplifier
  
• Hi-Fi Headphone Amplifier
  
• 100W Guitar Amplifier
  
• Death of Zen (DoZ) - A New Class-A Power Amp
  
• Soft-Start Circuit For Power Amps
  
• Thermo-Fan To Keep Your Amp Cool
  
• Audio Amp Output Power Limiter
  
• 55W (Originally 75W) Power Amplifier
  
• 300W Subwoofer Power Amplifier
  
• 20 Watt / Channel Stereo Power Amplifier
  
• Mini bench amplifier (LM386)
  
• 12 Watt Valve Guitar Amp
  

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  New DSP 10W AM transmitter with crisp audio! The long awaited AM transmitter is finally here. With built-in compression, limiting and low pass filtering. Covers shortwave, mediumwave and long wave.

  
  
  
  
  

Audio preamp circuits

• Microphone amplifier
  
• RIAA phono amplifier
  
• Low impedance microphone amplifier
  
• Dynamic microphone preamplifier
  
• Phono preamp
  
• Masthead preamp
  
• Preamplifier for microphone or guitar use
  
• Simple microphone preamplifier
  
• Tube microphone preamp
  
• Simple Stereo Electret Microphone Preamplifier
  
• Simple Stereo Electret Microphone Preamplifier
  
• Phono Preamp
  
• Simple microphone preamplifier
  
• ECM Mic preamp
  
• Hi Fi preamp
  
• Balanced microphone preamp
  
• Audio preamp
  
• Electret mic amplifier
  
• Audio preamplifier
  
• Vacuum Tube Microphone Preamp
  
• FET Preamp Cable
  
• Audio preamp
  

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  ARRL handbook, the holy bible of RF, a complete and extensive guide to radio frequency circuits and electronics in general (link goes to 2004 version)
  
  Automative, car and motorcycle schematics

• Electronic auto stethoscope
  
• Turn signal alarm
  
• Motorcycle turn-signal system
  
• Cigarette lighter 9V adaptor
  
• Analog Tachometer for Gasoline Engines
  
• Headlight On reminder with Light
  
• Adaptive Windscreen Wiper Control
  
• Car clock
  
• Car message display
  
• Car interval wiper
  
• Safety indicator light
  
• Speed limit alert
  
• Grand Cherokee Off-Highway Lights
  
• Engine control unit schematics
  
• Portable CD Player Adapter For Car
  
• Car battery charger
  
• Wireless Auto Tachometer
  
• Alternator Signal Detector
  
• Automotive alarm system
  
• Road ice alarm
  
• Automotive Anti-Lock Brake Control Driver
  
• Headlight reminder
  
• Breath Alcohol Tester controlling a car ignition system
  
• Simple car battery charger
  
• Parking sonar
  
• Fuel injector pulse width monitor
  
• BMW R Series Motorcycle Regulator Schematic
  
• 80188XL Engine Tachometer
  
• Integrate Fuel Pump Wire Security Cut Off with a Turbo Timer
  
• Simple Car Preamplifier and Artificial Earth
  
• FCD (Fuel Cut Defencer)
  
• Interface between GM's 5 Volt 8192 baud ALDL data stream and a PC serial port
  
• 5301 wideband fuel mixture display
  
• Wide Band Fuel Mixture Display
  
• 3rd brake light
  
• 12V to 9V car coverter
  
• Car Nicad charger
  
• Combination lock for car liftgate
  
• BMW motorcycle side stand protection mod
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  Data acquisition and data logging schematics

• Air flow detector
  
• Air flow detector
  
• Strain gauge sensor
  
• Digital Water Wave/Tide/Level Meter (PIC16F876)
  
• Self made data-logger V2.5 (second edition)
  
• Magnetometer
  
• Analog input section based on AD9220
  
• uModem 4+4/8 channel A/D board
  
• ADXL202 accelerometer to CV output
  
• Light direction sensor
  
• 12-Bit ADC interface
  
• Digital thermometer
  
• Universal flight controllers / datalogger
  
• Rain detector
  
• Home Brew Compass Sensor
  
• Using 555 Timer as an A/D converter
  
• ADC0804LCN 8-bit A/D converter
  
• Web-based thermometer project
  
• Low Flow-Rate Thermal Flowmeter
  
• Geiger counter
  
• Differential Capacitance Measurement for Tilt Meter
  
• Honey Bee counter (PDF)
  
• Capacitance type liquid level measurement (PDF)
  
• Thermostat node schematic
  
• Digital PC Oscilloscope
  
• Ultrasonic Range & Imager
  
• Precision Digital Altimeter
  
• Digital compass schematic
  
• Temperature datalogger
  
• Serial Port A/D-converter
  
• Centronics port D/A converters and low-pass filter
  
• LCD Thermometer
  
• Acceleration monitor using Analog Devices ADXL202
  
• Optical sensor using PIC12C508
  
• Wireless Liquid Level Sensing for Restaurant Applications
  
• Accelerometer Schematic
  
• Pressure Sensor-Based Altimeter Circuit
  
• Ultrasonic range finder circuit
  
• 1-wire barometer
  
• Water-level sensor
  
• Addressable ADC
  
• Electronic altimeter using PIC16F877
  
• Wireless weater station
  

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  SE3, turn your FM transmitter into STEREO FM TRANSMITTER. Digital/analog technology at work.
  
  
  Filter schematics

• Galaxy Noise Filter
  
• Low-pass active filter
  
• Filter Circuit for the Earthworm Seismic Data Acquisition System
  
• Active 2nd Order Filters
  
• RC Notch Filter (Twin T)
  
• Multiple Feedback Bandpass Filter
  
• CW filters
  
• Self-tune filter
  
• SSB AF filter
  
• Helical Resonator Notch Filter
  
• 3KHz low-pass filter plus audio amp (PDF)
  
• Active bandpass filters
  
• Bandpass filters
  
• Butterworth filters
  
• Narrow band audio bandpass filter
  
• Inversal notch and bandpass filter
  
• DC Accurate, Active RC Lowpass Filter
  
• Chebyshev Bandpass Filter
  
• Bandpass filters
  
• Chebyshev / Butterworth filters
  
• Biquad Active Bandpass Filter Schematic
  
• "A" Weighting Filter For Audio Measurements
  
• Multiple Feedback Bandpass Filter
  
• Digital signal processor (DSP) for radio communications
  
• 29.85 MHZ bandpass filter schematic
  
• 29.85 MHZ notch filter schematic
  
• LC filter design
  

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  Games and fun stuff (schematics)

• Visor cradle serial interface
  
• Electronic coin tosser
  
• Electronic craps game
  
• First response monitor
  
• VCR ping pong game
  
• Video ping pong game
  
• MBC5/CPLD for the GameBoy
  
• GameBoy Camera Parallel Port Interface
  
• Mobile robot (PDF)
  
• PSX controler to PC MIDI converter
  
• Dreamcast PC serial adapter
  
• GameBoy Cart Programmer
  
• Memory game
  
• 32 Kb x 8 emulator for the GameBoy
  
• Project: NES to Atari 2600 controller interface
  
• Battery Meter for Pinball Machines
  
• SRX1 (Stephane's Robotic eXperiment 1)
  
• Pine Racecar Victory Judge
  
• Interfacing Sony control stick to Empeg
  
• Electronic Nicad glow plug driver
  
• April Fools LEDs
  
• Pinewood Derby logic
  
• Quiz Master
  
• GameBoy Schematic
  
• GameBoy LCD schematic
  
• GameBoy Power & Cartridge schematic
  
• GameBoy ROM+RAM+MBC1 Cart Schematic
  
• GameBoy MBC1 circuit equivalent
  
• Super GameBoy schematic
  
• Quiz show indicator
  
• Dreamcast interface
  
• Bingo!!! (on your tv)
  
• Slot car TV cronograph
  
• Furby reverse-engineered circuit
  
• Sanyo 20EZ monitor Arcade Game (300k ZIP)
  
• Burger Time Arcade Game (500k ZIP)
  
• Dig Dug Arcade Game (800k ZIP)
  
• Frogger Arcade Game (500k ZIP)
  
• Galaga Arcade Game (542k ZIP)
  
• Gyrus Arcade Game (800k ZIP)
  
• Junior Pacman Arcade Game (400k)
  
• Ladybug Arcade Game (335k ZIP)
  
• Mappy Arcade Game (470k ZIP)
  
• Moon Cresta Arcade Game (300k ZIP)
  
• Mr.Do Arcade Game (554k ZIP)
  
• PacLand Arcade Game (316k ZIP)
  
• Pengo Arcade Game (313k ZIP)
  
• Q*Bert Arcade Game (600k ZIP)
  
• Qix Arcade Game (476k ZIP)
  
• Scramble Arcade Game (600k ZIP)
  
• Time Pilot'84 Arcade Game (870k ZIP)
  
• Xevious Arcade Game (450k ZIP)
  
• Magic Wand Conjuring Trick
  
• Quiz game circuit
  
• E.S.P. Conjuring Trick
  
• Video game system using PIC18F252 (direct video generation)
  
• Video game system using SX28 (direct video generation)
  
• DIT shutterglasses controller
  
• Tic-tac-toe game using PIC16F628
  
• Archery timer
  
• PIC micro Tetris game
  
• Magic lamp, IR remote control jammer and other fun circuits (PDF)
  
• Lego Mindstorms Double Rotation Sensor
  

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  Infrared based schematics

• IR detector
  
• Infrared body heat detector
  
• Stereo IR audio receiver
  
• General purpose IR receiver
  
• Wireless IR headphone transmitter
  
• Wireless IR headphone receiver
  
• Infrared remote control shutter release system
  
• Infrared transmitter for locomotives
  
• Infrared gate for door
  
• Infrared circuits for remote control
  
• Serial port controller infrared transmitter (PIC16F628)
  
• IR Receiver (Amplitude Modulated IR)
  
• IR Transmitter for Audio (Amplitude Modulated IR)
  
• Digibox interface
  
• IR remote control
  
• Long Range Infrared Remote
  
• iRDA to TTL interface
  
• 40KHz light receiver (PDF)
  
• 40KHz TV-VCR repeater (PDF)
  
• Micro based PIR to IR remote converter
  
• IR-related ASCII Schematics V1.00
  
• Infrared remote transponder
  
• Build an Infrared night scope
  
• Decoding IR Remote Controls
  
• IR detector
  
• PC IR Remote Control Hardware
  
• PC IR Remote Control
  
• An Ambient-Light-Ignoring Infrared Active Motion Detector
  
• Infrared Transmitter and Receiver schematic diagrams
  
• Pyroelectric Infrared Sensor
  
• Minimal Infrared transmitter for PC
  
• Simple IR transmitter circuit
  
• Simple infra-red detector
  
• AVR (AT90S2313) serial port infrared receiver
  
• Infra Red Switch
  
• IR remote control extender
  
• IR Remote Control Extender Circuit (Mark 2)
  
• IR Remote Control Extender Circuit (Mark 3)
  
• IR Link
  
• IR remote control tester
  
• 40khz IR Tester
  
• 555 timer 40khz IR Oscillator
  
• IR detector / emitter
  
• Fire-Stick infrared remote control
  
• Simple infrared remote control
  
• Infrared / Ultrasonic beacon
  
• Implementing Infrared Object Detection
  
• IR detector for robotics
  
• Computerized Infrared Remote
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
  Laser related power supplies and data transmission

• Light beam receiver for laser pistols
  
• 12V supply for He-Ne laser
  
• Laser diode transmitter
  
• Laser power supply
  
• Laser transmitter/receiver
  
• Laser harp
  
• Laser Telephone Receiver Circuit
  
• Fiber Optic Voice Communications
  
• Efficient Laser Supply
  
• 20MHz VCSEL 3mW laser test circuit (PDF)
  
• 10MHz to 20MHz laser light detector (PDF)
  
• Micro-power 40KHz burst laser diode driver (PDF)
  
• 40KHz laser burst detector (PDF)
  
• Modulated laser diode tester (PDF)
  
• Ar/Kr Ion Laser Power Supply
  
• Laser diode power supply circuits
  
• RS-232 Laser Transceiver
  
• HeNe laser power supply
  
• OPT201 Laser receiver
  
• OPT301 Laser receiver
  
• Laser transmitter schematics
  
• Diode Laser Power Supplies
  
• Laser bug circuit
  
• RS-232 Laser Transceiver
  
• Experimental laser data link
  
• Ar/Kr Ion Laser Power Supply Design
  
• Simple laser communicator
  

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  LED related schematics

• Big 7-segment LED display board with SPI interface
  
• LED Flasher
  
• LED pulser with audible output
  
• IR Illuminator
  
• Flashing Christmas LED display
  
• ICL7660 LED flasher
  
• LM3909 replacement using discrete components
  
• Color fade
  
• LEDs shimmer randomly as though on fire
  
• LED power supplies for AA cells
  
• 1.5 Volt LED Flashers
  
• AC Line Powered LEDs
  
• Astable Multivibrator
  
• 9 Second Digital Readout Timer
  
• 9 Second LED Relay Timer
  
• 16 Stage Bi-Directional LED Sequencer, other sequencer and flaser circuits
  
• 10 Stage LED Sequencer
  
• 28 LED Clock Timer
  
• Fading Red Eyes
  
• Two Transistor LED Flasher
  
• 16 Stage Bi-Directional LED Sequencer
  
• Expandable 16 Stage LED Sequencer
  
• LED Photo Sensor Circuit
  
• LED chaser
  
• 7 Segment LED Counter
  
• 7 by 10 LED Moving Sign ( 27C512 EPROM)
  
• Sequencial LED Flasher with Reversable Direction
  
• Tri Color LED Controller with Serial Interface
  
• 1.5V LED flasher B (PDF)
  
• Low current LED flasher (PDF)
  
• 1.5V LED flasher A (PDF)
  
• Flashing LED advertising badge (PDF)
  
• Flashing LED advertising badge (PDF)
  
• Pulsed LED test circuit (PDF)
  
• Low battery voltage flasher (PDF)
  
• Adjustable flashing LED
  
• PWM white LED drivers
  
• Heart of LEDs
  
• Christmas Star
  
• Christmas tree
  
• LED Counter
  
• PIC16F84 LED chaser
  
• PIC16F84 LED signboard
  
• PIC16F84 LED signboard 2
  
• White LED circuits
  
• Assorted LED circuits
  
• LED Mood Light
  
• LED Audio VU Meter
  
• Robot Beacon rotating light using PIC12C508
  
• LM3909 LED flasher
  
• Animated LED signboard (PIC16C84)
  
• Picxie 2 - 8x8 Animated LED Signboard
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
  Lighting schematics

• Garden light switch
  
• DMX lighting and special effects
  
• Microcontroller Multichannel Light Dimmer
  
• Digital timer light switch
  
• Hand clap lamp control
  
• Radio controlled light switch
  
• Disco style Strobe Light
  
• Varying Brightness AC Lamp
  
• 12 Volt Lamp Dimmer
  
• 120VAC Lamp Chaser Using Solid State Relays
  
• Flashing Neons (NE-51 / NE-2)
  
• Sequencing Neons (NE-51 / NE-2)
  
• Touch Activated Lamp
  
• 220V Flashing lights
  
• Coutesy lamp
  
• Bedside lamp timer
  
• TRIAC light dimmer
  
• 12VDC Fluorescent Lamp Driver
  
• Strobe light
  
• Adjustable Strobe Light
  
• RHINO8 EL Sequencer
  
• Light Sequenced Candelabra
  
• Light timer
  
• 5W Fluorescent light intensity modulator (PDF)
  
• 1W Fluorescent lamp night light (PDF)
  
• Low-voltage light dimmer
  
• Light chaser
  
• 4-channel dimmer rack
  
• PIC16F873 light controller
  
• Disco light controller
  
• Neon desklamp
  
• Electronic night light
  
• Neon lamp dimmer
  
• LED Mood Light
  
• LX-800 Lighting system
  
• Xenon Strobe Light
  
• Lamp flasher/dimmer
  

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Cyber max LCD, professional stereo FM transmitter at an affordable price!

 

Medical and health related schematics

• Snore alarm electronic device
  
• Heartbeat transducer
  
• ECG Amplifier
  
• EKG/EEG circuit
  
• Radiation Dosage-Rate Meter
  
• Heartbeat monitor
  
• Cranial Electrotherapy Stimulator
  
• Automated crib lights
  
• Jogging timer
  
• Tan timer
  
• Muscular Bio-stimulator
  
• Pedometer
  
• Simple lie detector
  
• EEG preamp, anti alias filter and isolation circuit
  
• Self Contained Electromyograph (EMG)
  
• Cardiac monitor
  
• Galvanic Skin Response (GSR) Schematic
  
• Brain-Wave Machine
  
• Lie detector
  
• Simple lie detector
  
• ECG project page
  
• The ESP SIM (Sound Impairment Monitor)
  
• Respiration system
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
  Microcontroller based schematics

• PIC based packet radio encoder (PDF)
  
• RS485-Version of the SAB80C535-Microcontrollerboard
  
• PC IR receiver based on PIC16F84
  
• Record and play fast 1-bit sound on a PIC micro
  
• AT89C2051/4051scanning 7-segment display and keypad
  
• AT89C2051/4051 Driving dot LED
  
• AT89C2051/4051stepper motor interface
  
• AT89C2051/4051connecting dumb terminal
  
• Motorola 68K SBC (single board computer)
  
• 8051 SBC (single board computer)
  
• Simple RS232C Level Converter using Transistors
  
• Motorola 68HC11 evaluation board
  
• C-52 EVB Robot Controller
  
• Mains clock controller using AT89C2051
  
• AT89C2051/4051 Easy-Downloader
  
• AT89C51/52/55 Easy-Downloader
  
• PIC16F84 programmer
  
• PIC16F84 miniature real-time controller
  
• Isolated RS232 for PIC16F84
  
• PIC16F84 debugging terminal
  
• MiniLOGGER V1.0
  
• Analog datalogger based on T89C51RD2
  
• Atmel 89C Series Flash Microcontroller Programmer
  
• Atmel 89C2051 prototype board
  
• AT89C2051 real-time controller
  
• PIC12C508 Night-light saver
  
• AT89C2051 Night light saver
  
• Atmel 8051 Flash Based-Microcontroller Programmer
  
• AT89C2051 Digital thermometer and clock
  
• 4-Channel Timer using Atmel 89C4051 and MAX7219 display driver
  
• PIC16F84 CW decoder (PDF)
  
• 12C508 Smart Lock
  
• 80C31 stepper motor controller
  
• Build a PIC controlled DDS VFO, 0 to 6 MHz
  
• PIC controlled DDS VFO, 0 to 6 MHz
  
• Basic Stamp Lightning Activity Monitor
  
• Parallel AVR programmer
  
• PIC16F84 line following robot
  
• PIC16C505 IR / wireless remote control
  
• Automatic door opener with PIC12C508
  
• RS485-like multi-drop bus with half duplex serial protocol
  
• WWWpic2 - A web server in a PIC
  
• PIC16F84 web server
  
• 50 MHz frequency counter, voltage meter & SWR/PWR indicator
  
• Microcontroller board using the Atmel AVR AT90S8535
  
• Programmer PIC16F84,12C50x and EEPROM 24Cxx
  
• RDS Encoder - digital part
  
• PIC programmer for serial port
  
• Fully functional PS/2 mouse based on the PIC16F84
  
• PIC 18 programmer (PIC18F458, PIC18F452, PIC18C252, PIC16C745, PIC18F6620, PIC18F6720)
  
• Freign vocabulary recollector
  
• Illuminate holiday destinations on a world map
  
• Embedded system to send e-mails (small TCP/IP stack)
  
• Speaking clock using PIC & ISD device
  
• Speaking doorbell using PIC & ISD device
  
• Whistle detector using 8-pin PIC
  
• PIXpand
  
• PIC16F877 to IDE interface
  
• 68HC11 stepper motor control
  
• 90S2313 AVR Robot Board
  
• POCSAG encoder/decoder
  
• Network Time Protocol AVR Clock
  
• DS1820 Temperature Sensor Readout Unit
  
• Rotating Sprocket Wheel Generator (PIC16F84)
  
• Talking PIC - based on SP0256
  
• Serial to parallel converter using the AT89C2051
  
• AT89C2051 serial COMs to LED driver
  
• PIC16F877 Programmer And Development System
  
• DS1820 Arbiter V2.00 Schematic
  
• Microchip PIC ICSP implementation
  
• 101 AT Keyboard to ASCII Decoder using 68HC705J1A MCU
  
• LCD Serial Terminal
  
• Propellor clock (PIC16F84)
  
• Optical sensor using PIC12C508
  
• Interfacing S-7800A to PIC16F877
  

SE4 DSP stereo encoder, setting new standards in value market!

• A Scenix (and PIC) Programmer
  
• MMC to PIC16F876 circuit diagram
  
• 8088 maximum mode SBC
  
• EZ80 single board computer schematic (Z80)
  
• 8051 Development System Circuit Board
  
• Voice recording and message retrieval system
  
• Interfacing a GPS to an LCD using a Microcontroller
  
• Long-period watchdog timer
  
• PIC16F84 Range Finder Project
  
• Generate video signals in real-time using a PIC16F84
  
• PIC ICD
  
• PIC Project #1 - RS232 to I2C Interface
  
• Galvanic decoupling of I2C bus
  
• Programmer PIC16F84,12C50x and EEPROM 24Cxx
  
• Dual PIC16C84 prototype board
  
• Graphic LCD interface
  
• FSK modem with PIC16C84
  
• Talking YODA project (PIC16C84)
  
• PIC16F84/PIC16F87x-In-System-Programmer
  
• Microcontroller interface for 5KW microwave oven
  
• Using an I2C Serial EEPROM with a Basic Stamp 2
  
• PIC16F84 Based Morse Code Reader
  
• AVR-Based Serial Port IR Receiver
  
• Interfacing piezo elements to a microcontroller
  
• Victoria TAFE programmer (based on AT89C2051)
  
• JDM programmer
  
• PIC micro programmer
  
• Speech recognition using HM2007
  
• PIC microcontroller servo motor interface
  
• PIC micro multiple servo motor interface
  
• PIC16F84 countdown timer
  
• PIC16F873 ultrasonic range meter
  
• PIC16F873 Digital clock
  
• PIC16F873 remote display
  
• PIC16F84 stepper motor controller
  
• Way small web server
  
• PICADC - a free, PIC based "intelligent" A/D converter
  
• 8051 development system circuit board
  
• 8088 maximum mode single board computer (SBC)
  
• Basic 89C2051 / 89C4051 circuit diagram
  
• Debugging dump terminal for 89C2051 designs
  
• Easy debugging terminal
  
• Galvanic decoupling of I2C bus
  
• Circuits interfacing piezo elements to a microcontroller
  
• Driving a TRIAC using a PIC12C508
  
• Isolated RS232C for PIC16F84
  
• Microchip ICD (in-circuit debugger) circuit diagram
  
• Microchip PIC ICSP implementation circuit diagram
  
• Interfacing NMEA GPS to LCD using PIC16F84
  
• PIC ICD (in-circuit debugger)
  
• PIC16C71 morse code callsign generator
  
• PIC16F84 to LCD interface
  
• PIC16F84 I/O expander with PicBasic
  
• Scanning 7-Segment & Keypad
  
• 10-key serial keypad encoder
  
• Simple RS232C Level Converter using Transistors
  
• Talking PIC microcontroller using SP0256
  
• PIC-Programmer 2
  
• Connecting PIC12C508 8 to 93AA46 serial eprom
  
• KD7LMO Micro Beacon (PIC18F252)
  
• GPS LCD Display Project
  
• PIC16F84 LED chaser
  
• PIC micro LED projects
  
• PS/2 keyboard keystroke logger based on Atmel 89C2051
  
• Electronic distance meter based on Motorola 68HC908QY4
  
• Fan timer based on Motorola 68HC908QT2
  
• Atmel AVR and 8051 series ISP programmer
  
• AT89C2051 line-follower robot
  
• Night light saver (PIC12C508)
  
• USB and GLCD expansion board for 8051 SBC
  
• Basic stamp interface circuits
  
• Microcontroller sensor and actuator interfaces
  
• Giant money counter (PIC16F876)
  
• PIC12C509 logic gate replacement for nitrogen filler
  
• PIC demo board
  
• PIC12C509 Gym Timer
  
• PIC LCD and Keypad driver
  
• PIC12C508 Phase Controller for 2kW heater
  
• PIC16F84 TRIAC / IGBT brightness phase controller
  
• PIC16F84 pulse monitor with date/time output (ZIP)
  
• Programmer for the 68HC705C8 MicroController
  
• 27c801 EPROM Programmer Project
  
• LCD to PIC16C54 schematic
  
• 68HC11 based RDS decoder
  
• Acceleration monitor using ADXL202 and AVR
  
• 40+ MHz 5-digit frequency counter with an AVR 2313
  
• Interfacing DRAM to AT90S8515
  
• Temperature monitor/controller: AVR 2313 / DS1621
  
• PIC micro to ISA bus interface
  
• PIC16C84 VT-52 Emulator for Linux
  
• Microchip PIC ICD (in-circuit debugger)
  
• Tony Nixons Pocket Programmer (PIC)
  
• PicoWeb V5.1 (AT90S8515) tiny web server
  
• Atmel 89C2051 In-Circuit Programmer Schematic
  
• 8051 Development System Circuit Board
  
• 8051 Development System Circuit Board
  
• Microprocessor using Xilinx FPGA
  
• Temperature controlled based on AT89CX051
  
• I2C LCD interface
  
• AFSK 1200 Modem based on PIC16C620
  
• PicCon - Hidden Radio Transmitter Controller
  
• PIC16F84 tone generator with source code
  
• PIC16F84 tone generator
  
• PIC16F84 tone generator (6-Bit)
  
• AVR Beacon Super Keyer
  
• AVR Frequency Counter
  
• AVR Digital Voltmeter
  
• AVR Signal Generator
  
• Ser-Key 10-Key Serial Keypad Encoder
  
• 2-wire LCD interface using PIC16CF84
  
• PIC16F84 Serial I/O-expander with PicBasic
  
• RS 485-RPT Schematic
  
• Camera remote control system using Basic Stamp
  
• Low cost Atmel in-system programmer
  
• Ultra low-cost programmer for AT90S family
  
• AVR to USB interface
  
• Programable LCD counter with memory backup based on Atmel AT90S1200A
  
• Connecting AT90S2313 with LCD display 2x16 char and 4x4 keypad
  
• Atmel AVR RCEN fuse bit programmer
  
• Electronic safety lock based on ATtiny26
  
• GSM SMS remote control using AVR microcontroller
  
• 128x64 LCD Driver for AT90S2313 (ZIP file)
  
• Connecting LED to PIC Micro I/O pins (PDF)
  
• Microprocessor RS-232 Reset
  
• AT90S8515 experimenter board
  
• Multi-chip programmer for PIC microcontrollers
  
• Buffered PIC chip interface
  
• A PIC-Based Keyboard Emulator
  
• PIC-based robot
  
• ScanMate audio activated recorded
  
• PIC vacuum fluorescent display interface
  
• PIC18F252 bootloader schematics
  
• PIC16F876 Datalogger
  
• GPS Repeater
  
• Kodak DC-20 camera interface (PIC12C509)
  
• Kodak DC-20 camera interface (PIC16F84)
  
• PIC ICD in-circuit debugger circuit diagram
  
• PIC programmers for parallel port
  
• Wisp628 ISP Microchip PIC Programmer
  
• WLoader - PIC16F877 application loader / bootloader
  
• Nixie clock (PIC16F876)
  
• Zilog Z80 thermostat embedded web server
  
• Picxie 2 - 8x8 Animated LED Signboard (PIC16F84) Picxie 2 - 8x8 Animated LED Signboard
  
• 10 tricks for interfacing to the PIC16C508
  
• Interfacing the PIC16C508
  
• PIC 5x7 display
  
• Analog to digital conversion notes
  
• Multi-chip programmer
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
  Misc audio (also see Music, Amplifiers, Preamp)

• Electronic siren
  
• Two-tone siren
  
• Underwater microphone
  
• Code practice oscillator
  
• Noise generator
  
• Electronic whistle
  
• Twin-T Audio Sine Wave Oscillator
  
• 1.5V Audio Amplifier
  
• Low Power Op-Amp - Audio Amp (Intercom)
  
• 555 Tone Generator (8 Ohm Speaker)
  
• 3 Transistor Audio Amp (50 milliwatt)
  
• Low Frequency Sinewave Generator
  
• Automatic Charger for Battery Operated Hi-Fi Preamps
  
• Audio level indicator
  
• Room noise detector
  
• Amplifier timer
  
• Bell ring generator
  
• Amplified ear
  
• Precision audio millivoltmeter
  
• Six-channel Mixer and Amplifier
  
• Audio Signal Source
  
• Analog VU meter
  
• Voltage controlled amplifier
  
• Audio graphic equaliser
  
• Intercom preamp
  
• FET audio mixer
  
• Microphone mixer
  
• Tone control
  
• Digital volume control
  
• Sound level meter
  
• CMOS IC audio oscillator
  
• Three band Active Tone Control
  
• Automatic gain control (AGC) circuits
  
• Audio frequency meter
  
• Bull Horn
  
• Sound Mixer/Amplifier
  
• Very loud beeper (PDF)
  
• Digital noise generator (PDF)
  
• Tone display system
  
• Tube amplifier
  
• Condenser microphone hookup
  
• Phase shifter
  
• Paradoxical Sound Syntheizer
  
• Various tube crossover circuits
  
• Bias circuits
  
• Audio line isolator
  
• Dynamic microphone to electret microphone input
  
• Line level signal to microphone input adapter
  
• Simple two line output combiner
  
• Electret microphone powering circuits
  
• Use amplifier phono input as line level input
  
• Speaker signals to line level inputs
  
• Spring reverb unit
  
• Sine wave generator
  
• Simple amplifier
  
• 3-Band equalizer
  
• 6-Input mixer
  
• Doorphone intercom
  
• Stereo line driver
  
• Audio notch filer
  
• Peak reading audio level meter
  
• Tone control
  
• Speaker Microphone Circuit
  
• Electronic canary
  
• Electronic siren
  
• Microphone phantom power supply
  
• Voltage Controlled Mixer w/Modulator
  
• Dual Voltage Controlled Oscillator w/Modulator
  
• Dual Voltage Controlled Filter w/Modulator
  
• Stereo Ducker
  
• MS Stereo Decoder
  
• MS Stereo Microphone
  
• RIAA Equalized Stereo Phono Preamp
  
• Tube active crossover
  
• Improved PL tone decoder
  
• Magnetic cartridge amplifier
  
• LM358 preamp
  
• Sound detector
  
• Tone detector
  
• Tone generator
  
• Warbler
  
• Voltage Controlled Panner
  
• Low Noise Microphone Preamplifier
  
• Bridging Adapter For Power Amplifiers
  
• Simple Surround Sound Decoder
  
• Simplest Ever Amplifier Bridging
  
• Stereo Width Controllers
  
• Power Amplifier Clipping Indicator
  
• Phono Preamps For All
  
• Digital Delay Unit For Surround Sound
  
• Parametric And Sub-Woofer Equaliser
  
• High Quality Sound Mixer
  
• Loudspeaker Protection and Muting
  
• Direct Injection Box for Recording & PA Systems
  
• Minimalist Discrete Hi-Fi Preamp
  
• Signal Detecting Auto Power-On Unit
  
• Load Sensing Automatic Switch
  
• Amplifier thermal protection
  
• Active Sub-Woofer and Controller
  
• Balanced Line Driver & Receiver
  
• VU And PPM Audio Metering
  
• Variable Amplifier Impedance
  
• Linkwitz Cosine Burst Generator
  
• Low Noise Balanced Microphone Preamp
  
• Fast Audio Peak Limiter
  
• Subwoofer Equaliser
  
• Surround Sound Decoder Mk2
  
• Audio mixer
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
  Miscellaneous schematics

• Ultrasonic radar
  
• Mobile APRS / GPS tracking system
  
• Electronic fish lure
  
• Ultrasonic sound receiver
  
• Experimental data transmitter for fiber optics
  
• Experimental fiber optic receiver
  
• Ion detector
  
• Darkness monitor
  
• Electroscope
  
• Simple event counter
  
• Geiger counter
  
• Light detector
  
• Short-circuit beeper
  
• LM 1800 FM stereo decoder
  
• Glitch detector
  
• MAX924 bar-graph level gauge
  
• Ultrasonic generator
  
• Negative ion generator
  
• ELF Monitor
  
• Chaos generator
  
• Simple BFO metal detector
  
• Voltage Comparator Information And Circuits
  
• Build Your Own Digital Setting Circles For Your Astronomical Telescope
  
• PL tone generator (NE567)
  
• Bat detector
  
• Bat detector microphone pre-amplifiers
  
• Full-duplex doorphone with 3 wires connection
  
• G Strain energy absorber
  
• RDS Encoder
  
• Toggle Switch Debounced Pushbutton
  
• RDS Encoder
  
• Discrete Set/Reset Flip Flop
  
• Monostable Flip Flops (one shot)
  
• Discrete Bistable Flip Flop
  
• Talking Morse Code Practice Computer
  
• Plant watering watcher
  
• Capacitance sensor
  
• Whistle responder
  
• Nocturnal animals whisker
  
• 12V DC electronic door chime
  
• Biasing Op-Amps into Class A
  
• Parasite zapper
  
• Bleeper box for time reference
  
• Analog computer
  
• BayComm packet modem
  
• Morse monitor
  
• HamComm modem interface
  
• Morse paddle keyer
  
• UV light box
  
• Hardware Random Bit Generator
  
• Random noise generator
  
• Analog pulse counter
  
• Analog opto-isolator
  
• Pulse width modulators (PWM)
  
• Pulse width to voltage converter
  
• Fantastic Atom Expander
  
• Black Light
  
• Computerize Your Room/Home
  
• Flash slave trigger
  
• Suddent ionospheric disturbance (SID) receiver
  
• A Visual CW Zero Beating Aid
  
• A two-way Morse practice set
  
• Magnetic levitation device
  
• Tesla power receiver
  
• Lazer Tag Equipment Modifications
  
• Garmin GPS data interconnect
  
• Inexpensive APRS Weather Station
  
• Walking robot
  
• Basic op-amp circuits
  
• Power line FM intercom
  
• Intercom circuit
  
• Lightning Storm Detector
  
• Large LCD Display Buffering Driver
  
• Text to speech converter
  
• Ion detector
  
• 1uS light pulse descriminator plus F to V converter (PDF)
  
• Broadband 2MHz optical fiber receiver (PDF)
  
• Modulated light received (PDF)
  
• 1uS light pulse receiver plus post amp (MISC)
  
• Broadband 5MHz optical fiber receiver (PDF)
  
• High-speed light receiver (PDF)
  
• Basement doorbell beeper (PDF)
  
• Time to dust indicator (PDF)
  
• Low-power optical interrupter (PDF)
  
• Simple nitrogen spark generator (PDF)
  
• Ultrasonic transducer oscillator circuit
  
• Build logic gates using discrete parts
  
• Jacob's Ladder
  
• Sudden Ionospheric Disturbance (SID) Receiver
  
• A selection of robotics projects
  
• Bat detector (new)
  
• Vat detector (old)
  
• Variety of quick designs
  
• Gold wafer (smartcard) programmer
  
• Making a FRED photopopper
  
• GPS receiver support kit
  
• Griffith Observatory Tesla Coil
  
• Fogger smoke machine
  
• Dinsmore 1490 digital compass
  
• Geiger counter
  
• Electric field disturbance monitor
  
• Inexpensive seismometer project
  
• Digital dial
  
• Speech recognition using HM2007
  
• GPS receiver interface
  
• Doorbell for the Deaf
  
• Electromagnetic field detector
  
• Insect Repellant
  
• High Quality Intercom
  
• Magnetic Gun.
  
• Metal detector
  
• Static Electricity / Negative Ion Detector
  
• Ultrasonic dog whistle
  
• Popular Electronics Ultrasound Detector
  
• An Inexpensive X-ray Machine
  
• Navigator 555A radio direction finder (RDF) circuit diagram
  
• Magnetic levitation circuit
  
• PE3342 Programmer Schematic
  
• u-Blox GPS receiver board
  
• Assorted digital circuits
  
• Basic electronic circuits
  
• Miscellaneous simple circuits
  
• Digital Call Sign Annunciator
  
• Monitor output from Motorola Oncore GPS engine in HP Z3801A in GPS Disciplined Oscillator
  
• Ultrasonic switch
  
• Sound finding cricket with phase detector
  
• Sound finding cricket
  
• APRS GPS tracker schematic (PIC16C73)
  
• Common Ground for Older VPW Circuit
  
• Very basic circuits
  
• Bat detector
  
• FCTS Project
  
• Smooth Tone Clickless CW Sidetone Generator
  
• Morse Code Beacon Keyer
  
• Lightning Activated Camera Shutter Trigger
  
• Simple metal detector electronic circuit
  
• Three Power Supplies for the Garmin GPS-20 Sensor Board
  
• Driving N-channel FETs from TTL
  
• Miniature Self-Powered Autonomous Robot
  
• Morse Code Practice Keyer 1
  
• Morse Code Practice Keyer 2
  
• 741 Light Sensor
  
• Fluid level detector
  
• The Aisin-Seiki GPS-Receiver (The "US$20 GPS")
  
• Morse code display
  
• Intercom schematic
  
• Scaling ADXL50 accelerometer output
  

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  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
  Model and remote control schematics

• Snake throat muscle controller
  
• Handy cricket for robotic applications
  
• Incline Railway Control Circuit
  
• A Receive Signal Decoder
  
• 27Mhz toy car receiver
  
• 27Mhz toy car transmitter
  
• One ounce rocket ejection timer
  
• LED traffic lights
  
• Two-tone siren
  
• Proportional radio remote control
  
• Alf: The Robotic Matchbox car
  
• Seaplane schematic
  
• Model Rocket with Video Camera
  
• Signal breaking module
  
• RF serial link for robot
  
• PIC based rocket altimeter
  
• Robot with PIC16F84 brain & InfraRed eyes
  
• 0-10V control for RC servos
  
• Robotic microcontroller board
  
• Multi Rocket Launcher
  
• Model rocket launch controller
  
• Pad launch controller for model rockets
  
• Simple flashing light circuit
  
• Simple flashing light circuit
  
• A dual alternating flashing light circuit
  
• Simple flashing light circuit
  
• A dual tandem flashing light circuit powered by a 9 volt battery
  
• Simulate the Gyralite (dual flashing headlights).
  
• Simple train detector using ambient light and a photocell
  
• Simple charge rate monitor
  
• Deluxe charge rate monitor
  
• "CLONEPAC" memory module for Futaba 8UAF/8UAP
  
• Battery pack discharger
  
• Plane locator
  
• Plane locator 2
  
• Battery low voltage alarm
  
• Battery low voltage alarm 2
  
• Ultimate battery low voltage alarm
  
• R/C digital camera controller
  
• R/C helicopter camera
  
• Building an RF Remote Control System
  
• Motor walker circuit
  
• 250-amp Speed Controller for RC cars
  
• Spider robot electronic project page
  
• Two tone train horn
  
• R/C Emergency locator alarm
  
• Remote switch for radio-control aircraft accessories
  
• Radio Control Battery Backup
  
• Glow Plug driver for model engines
  

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  Motor and general control schematics

• Bridge head
  
• PWM motor controller
  
• Transistor relay driver
  
• Latching relay driver
  
• Relay delay circuit
  
• Touch switch
  
• Low voltage DC motor speed controller
  
• Flashing neon christmas lights
  
• Three input first response monitor
  
• Switch-on delay circuit
  
• Electronic thermostat
  
• LM3911 temperature controller
  
• Programmable light-activated relay
  
• Simple 10 Stage Control Box
  
• One component stepper motor driver
  
• Dual Stepping motor drivers using UDN2540
  
• PWM DC motor control with SG3525
  
• Stepper Motor Driver using TEA3718/3717
  
• Microstepping with PBM3960 and TEA3718
  
• DC Motor Driver with L6203
  
• Stepper Motor Driver using L298 and L297
  
• Several stepper motorol control circuits
  
• Wireless RF PWM dual motor controller
  
• H Bridge Motor Control Circuits
  
• Motor speed controllers
  
• Ceiling fan speed control
  
• Delayed off light switch
  
• Deoderizer fan timer
  
• Electronic Thermostat Relay Circuit
  
• Interfacing 5 volt CMOS to 12 volt loads
  
• Light Activated Relay
  
• CMOS Toggle Flip Flop With Relay(CD4013)
  
• 555 Timer Monostable Circuit Using Pushbutton
  
• Dual Channel Servo Pulse to H-Bridge Interface
  
• Current loop interface
  
• Switching solenoid driver
  
• Modular relay system
  
• Light/dark detector
  
• Pulse Width Modulation DC Motor Control
  
• Stepper motor controller
  
• Touch switch
  
• Pump controller
  
• H-Bridge motor controller (5 amps, 100 watts)
  
• Dual Channel Servo Pulse to H-Bridge Interface
  
• Servo pulse to PWM converter
  
• 12V Sump Pump Control
  
• Rolling code 4-channel UHF remote control
  
• DC Motor Speed Controller
  
• 3 Phase Brushless DC Motor Xtal Based Controller
  
• DC motor controller
  
• Garden moisture controller
  
• Overload Voltage Protection with Automatic Reset
  
• Pulse Width Modulator
  
• Pulse Width Modulator Motor Speed Control
  
• Pushbutton one-shot and latch (PDF)
  
• Charge coupled bi-directional power MOSFET relay (PDF)
  
• Finger touch activated switch (PDF)
  
• Machine vibration triggers hour meter (PDF)
  
• Solid state relay (PDF)
  
• Line-powered Xenon flash transmitter (PDF)
  
• 9V Xenon photoflash controller (PDF)
  
• AC switching with TRIAC from TTL
  
• Control 120VAC relay with TTL
  
• Driving a relay with a CPU
  
• Power-line Appliance Controller
  
• Simple Switched Servo Driver
  
• Combination-controlled, fully customizable RF remote control
  
• Thermoelectic controller (scriptable thermometer)
  
• Stepper motor positioner
  
• Stepper motor driver
  
• Thermostat
  
• Frequency switch
  
• PIC16F84 RF remote controller
  
• Stepper motor controller
  
• H-Bridge shematic
  
• DS1821 programmable thermostat
  
• Hot Water Tank Indicator
  
• Temperature monitor
  
• Cold activated switch
  
• Voltage comparator switch
  
• Dark activated switch
  
• DC Push Button Motor Control Circuit
  
• Light detector
  
• DC Motor Reversing Circuit
  
• Sound operated switch
  
• LDR light/dark activated relay switch
  
• Touch Switches
  
• 6090 digital decoder schematics
  
• Assorted relay control circuits
  
• Adjustable Voltage motor controller
  
• Serial servo controller
  
• DC Motor-Driver H-Bridge Circuit
  
• PWM Motor Speed Controller / DC Light Dimmer
  
• Constant Temperature Circuit
  
• PWM DC Motor Speed Control
  
• Solenoid starter
  
• CO2 controller for planted tanks
  
• Light activated relay
  
• Delayed shutter control for Kodak DC-20
  
• Gasoline generator automatic throttle controller
  
• Block power switching module
  
• MOSFET H-BRIDGE schematic and theory
  

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Cyber max LCD, professional stereo FM transmitter at an affordable price!

Music related schematics (also see Audio)

• Audible metronome
  
• Visual metronome
  
• Peak-reading meters
  
• Octave screamer
  
• Amiga MIDI interface
  
• Apple Mac to MIDI synthesizer interface cable
  
• Apple Macintosh MIDI interface schematic (basic version)
  
• Apple Macintosh MIDI interface schematic (deluxe version)
  
• Standard MIDI to MIDI interface cable diagram
  
• Simple MIDI switcher
  
• MIDI interface / cable tester
  
• MIDI keyboard
  
• MIDI merger schematic
  
• 25-pin PC serial port to MIDI synthesizer interface cable
  
• 9-pin PC serial port to MIDI synthesizer interface cable
  
• Serial MIDI interface
  
• Microcontroller MIDI interface
  
• MIDI keyboard circuit
  
• Spring reverb unit
  
• Colour organ light
  
• MP3 Player
  
• Metronome and pitch generator
  
• Mini metronome
  
• Compact Flash / IDE MP3 Player MKI
  
• Simple colour organ
  
• Guitar fuzz effect
  
• 8 note tune player
  
• Colour (Sound) Organ
  
• Transisor organ
  
• BookPC Car MP3 Player
  
• Yet Another Mobile MP3 Player
  
• Wave Multiplier for music synthesizers
  
• Vibrato Circuit for Guitar, Steel, Bass, Etc.
  
• MIDI status indicator
  
• Zonk Machine and Treble Booster
  
• Simple line mixer
  
• Simple MIDI tester
  
• MIDI Controller Footpedal
  
• DIY Serial MIDI Interface (80C51/80C31 Version)
  
• Electronic metronome
  
• Sound Effects Generator
  
• Sound Effects Generator 2
  
• Digital Guitar Tuner
  
• Drum tone oscillators
  
• Analog MIDI synthesizer
  
• Spring reverb
  
• MIDI to CV interface
  
• Dual phantom power pre-amp
  
• Four channel fuzz box
  
• Theremin controller
  
• Vocal zapper
  
• MIDI drum machine project
  
• MIDI Drum Machine Analog Input Schematic
  
• Guitar Reverb Pedal
  
• Guitar Tremolo Unit
  
• Spring Reverb Unit For Guitar
  
• Ultra Simple Bass Guitar Compressor
  
• Vox AC30 Guitar Amplifier Simulator
  
• Guitar Vibrato Unit
  
• Musical Instrument (Expandable) Graphic Equaliser
  
• Midibox 64
  

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  PC related schematics

• I2C printer port adaptor
  
• RS232C Level Converter
  
• PC electrically isolated RS422 interface using SN75176B or MAX485
  
• PC electrically isolated RS485 interface using MAX487 or SN75176B
  
• Short circuit protected power supply from PC 12V supply
  
• Isolated Full Duplex RS232C Interface
  
• RS232 DB-9 switch to flip between two serial ports
  
• DB-9 Connector to DB-25 (both RS-232)
  
• Mac Serial Port (RS-422 DIN-8) to RS-232 DB-25
  
• Modem Rockwell RCV336/ACF model V1433VQR ext.
  
• Genius Mouse schematics
  
• EEPROM programmer
  
• Commodore 64 24-bit parallel port interface with 8255
  
• Sound Card Interface with Tone Keyer
  
• RGB oo Monochrome converter - Matches impedance of PC to CCTV monitor
  
• Ericsson phone to PC serial port interface
  
• PC serial port receiver
  
• Parallel port relay interface
  
• ISA 48 I/O digital card
  
• PC infrared iRDA interface using TFDS 4500
  
• Jupiter card programmer
  
• USB to RS232 Dongle
  
• Parallel (Printer) Port Interface
  
• RS-232 line monitor and loopback cables
  
• The KD2BD Pacsat Modem
  
• A Serial Infrared Remote Controller
  
• PC Serial and Parallel Port Software and Interfaces
  
• Interfacing 16x2 character :LCD to parallel port
  
• RS-232 Protocol Analyser
  
• Interface cable for Casio QV-200 digital camera
  
• Radio clock for PC's
  
• A PC-Based LowFER Frequency Synthesizer
  
• General purpose 48-bit ISA parallel I/O card
  
• Power from RS-232 port
  
• PCI to ISA converter
  
• WatchDog for ISA Bus
  
• 4-channel 8-bit analog-to-digital converter for PC
  
• Printer port ADC
  
• Parallel port ADC based on MAX147
  
• Analog Signal Acquisition for PC Printer Port
  
• More accurate PC/AT clock
  
• Getting power from RS-232 interface
  
• Barcode scanner
  
• Build your own iRDA SIR Transceiver (Dongle) using MCP2120
  
• PC thermometer
  
• Dive computer interface
  
• Parallel port servo controller
  
• GPS receiver (Gamin, Eagle etc) to PC interface cables
  
• Connect two CD-ROM drives to one soundcard
  
• Headphone driving circuit for soundcards
  
• Get power out of PC parallel port
  
• Null Printer Adapter
  
• PC speaker volume control circuit
  
• How to get power from PC to your circuits
  
• RS-232 surge protection
  
• Simple RS-232 serial port buffer circuit
  
• Get power out of PC RS-232 port
  
• Sound Blaster Microphone Preamplifier
  
• Sega 3D glass interfacing circuits
  
• Convert Atari-style joystick to PC joystick port
  
• Fake Joystick circuit
  
• Using the joystick port as general purpose input
  
• Connect other circuits to PC joystick port
  
• Schematic of a standard PC joystick
  
• Simple PC SmartCard reader
  
• Fax to modem interface
  
• Analog to Digital Conversion (ADC) and Communicating with a PC
  
• Temperature sensor for PC
  
• Interfacing to an IBM PC/AT keyboard
  
• PC interface for point controller
  
• Linux Infra-red Remote Control (LIRC)
  
• Homebuilt RS232 LCD Interface
  
• Compter microphone
  
• CCD linear image sensor to PC parallel interface
  
• Laptop Computer Serial Port Power Booster
  
• Assorted computer interface circuits
  
• HamComm Interface
  
• Apple II/II+/IIe IDE Drive Interface
  
• Basic Stamp I & PC Relay Controller
  
• RS-232 to TTL cable
  
• Hi-Fi PC Speaker System
  
• IDE hard-disk interface for Amiga 500
  
• How to construct Garmin GPS receiver interface cables
  
• iRDA printer adapter
  
• 160 Baud ALDL Hardware Interface
  
• AT PC Power Supply 1
  
• AT PC Power Supply 2
  
• AT PC Power Supply 3
  
• AT PC Power Supply 4
  
• AT PC Power Supply 5
  
• iLINK Interface
  
• Digital Signals Decoding Interfaces
  
• 9-pin null modem cable
  
• RS232 - Lowe HF-225 interface
  
• RS232 to IrDA convertor using Vishay TOIM3232
  
• Interfacing PC sound card to SSB rig
  
• Supply Derives Power From 3-Wire RS-232 Port
  
• 24-line PC digital interface (PDF)
  

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  PDA interfaces and related schematics

• Casio interface circuits
  
• SHARP palm-top/hand-held to RS232 serial converter
  
• Interfacing ultrasonic range finder to BrainStem
  
• Hamamatsu UVTron Interface to a BrainStem
  
• Casio interface cable
  
• Casio organiser hardware
  
• MIDI interface for Palm computers
  
• MIDI interface for Palm cradle
  
• MIDI interface for Visor USB
  
• MIDI-USB Cradle for Visor (Deluxe, Platinum)
  
• MIDI interface for Visor
  
• Casio datalogger
  
• Interfacing ADXL202 accelerometer to PalmPilot
  
• PalmPilot audio interface
  
• PalmPilot cradle to modem adapter
  
• PalmPilot connector pinouts
  
• PalmPilot serial port interface
  
• PalmPilot memory schematics
  
• Aladin interface
  
• PalmPilot turbo boost guage interface
  
• IBM PC keyboard to PalmPilot interface
  
• Aladin interface using op-amp
  
• Wireless local network for PalmPilot (large PDF)
  

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  Power supplies and control schematics

• Power supply provides +5VDC regulated, +10VDC unregulated and 7.5VAC
  
• 13.5KV power supply
  
• Kirlian device supply
  
• LM317 adjustable power supply
  
• LTC1265 Nicad charger
  
• Single cell lithium battery charger
  
• Smart battery charger
  
• Battery charge indicator
  
• Lead acid trickle charger
  
• 12B Battery condition indicator
  
• Alkaline battery charger
  
• Alternative power source for Magellan GPS receivers
  
• Power Tool Torque Control
  
• Generating Negative 5 Volts from 9 Volt Battery
  
• LED Battery Condition Indicator
  
• LM317 Variable Voltage Regulator
  
• LM317 Regulator With Pass Transistor
  
• High Current Regulated Power Supply
  
• Simple Variable Voltage Source
  
• Various switching power supplies
  
• Variable 3 - 24 Volt / 3 Amp Power Supply
  
• 2 watt switching power supply
  
• Variable Voltage and Current Power Supply
  
• Low Power DC to DC Converter
  
• Constant Current Battery Charger
  
• Intelligent NiMH/NiCd switched mode fast charger
  
• Variable DC power supply
  
• Nicad battery charger
  
• Simple power supply
  
• Voltage converter
  
• Bench power supply
  
• Easy power supply
  
• Valve power supply
  
• 6V to 12V Converter
  
• Tesla coil / HV generator
  
• High Current Power Supply
  
• Dual Polarity Power Supply
  
• High Voltage High Current Power Supply
  
• Transformerless Power Supply
  
• Fixed Voltage Power Supply
  
• Voltage Inverter
  
• Voltage Inverter
  
• Dual power supply
  
• 1A Variable Regulated Power Supply
  
• Negative voltage generator
  
• 12V battery capacity tester
  
• NE555 Low Voltage Battery Disconnect Circuit
  
• 33 Volt DC To DC Converter
  
• Automatic AC voltage (110/240) selector
  
• Variable 0-5A Current Source
  
• Ground Fault Interupter
  
• Intelligent battery charger
  
• 12 Volt DC Load Control and Battery Protection
  
• Low battery indicator
  
• Variable power supply
  
• Switching Power Supply
  
• Low Power DC Quadrupler
  
• Surge protector
  
• Ultimate power supply
  
• Variable Regulated Power Supply
  
• Power reminder beeper (PDF)
  
• Unplugged power cord alarm
  
• Machine power loss beepter (PDF)
  
• Low-dropout 12V regulator (LM324)
  
• HV supply: 12VDC in, 12KV out
  
• Generating -5VDC from +5VDC
  
• Filtering PC bus POWER
  
• Bidirectionall power inverter
  
• Nagative voltage generation using 555 timer
  
• High current regulated power supply
  
• One 9V battery gives +18, +25, +33V
  
• +9V *and* -9V from one battery
  
• Battery charger
  
• Adjustable power supply using LM317
  
• Simple +5V power supply circuit
  
• 12 Vdc - 120 Vac Inverter Schematic
  
• +12V/-12V Power supply unit
  
• +/-12V -> +/-5V Power unit
  
• +5V Switching regulator (1)
  
• Switching regulator (2)
  
• Electric power controller
  
• +30V power supply with +5V
  
• +30V DC-DC converter
  
• DC/AC inverter (2)
  
• DC/AC inverter (1)
  
• PIC16F873 DC motor speed controller
  
• 12V 30A power supply
  
• Dual regulated power supply
  
• Fuse blown indicator
  
• Gyrator circuit
  
• Variable power supply
  
• LM317 Regulator Circuit
  
• Nicad battery charger
  
• Regulated 12V supply
  
• Unregulated power supply
  
• Snowmobile GPS power adapter
  
• Simple switching power supply
  
• Assorted power source and control circuits
  
• 12 volt battery monitor
  
• 12 volt power supply
  
• 5 volt power supply
  
• Battery voltage monitor
  
• LM3914 battery monitor
  
• Multiple voltage power supply
  
• Voltage doubler
  
• Voltage inverter
  
• PWM Motor Speed Controller / DC Light Dimmer
  
• PWM Motor/Light Controller
  
• Low Power LED Voltmeter
  
• PWM Motor/Light Controller
  
• PWM Motor/Light Controller variants
  
• Low Power LED Voltmeter
  
• Temperature Controlled NICD Charger
  
• Simple Capacitance Multiplier Power Supply For Class-A Amplifiers
  
• Simple DC Adapter Power Supply
  
• Variable Dual Lab Power Supply
  
• Battery Charger Ideas
  
• Power control for arc welders and other inductive loads
  
• Charger for gel lead acid batteries
  
• Nicad battery cycler
  
• Battery Characterizer
  
• Nicad Battery Discharger/Capacity Indicator
  
• 200 Watt Modified PC Power Supply 13.5 Volt 14 Amp
  

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  300W amplifier for your FM transmitter, don't let the big boys bully you!
  
  
  Radio-frequency schematics (also see Transmitters)

• UHF oscillator
  
• Economoy short-wave radio
  
• Linearized RF detector
  
• Two-band radio
  
• Shortwave conveter for scanners
  
• FM Bug
  
• AM Radio
  
• Toroidal coil RF shortwave receiver
  
• Crystal radio
  
• CW RECEIVER 40/80 meter CW receiver
  
• TRF AM Receiver circuit
  
• WLW 500KW Transmitter Schematic
  
• AM-Receiver for Aircraft communication (118.250MHz)
  
• AM receiver for aircraft communications
  
• 45-860MHz Radio receiver based on UV916-tuner
  
• 80 Meter CW ARDF receiver
  
• Four channel RF remote control
  
• CW zero beat indicator (PDF)
  
• Build your own VLF Receiver
  
• Receiver building blocks
  
• Simple wireless radio data link
  
• RX3302 receiver module schematic
  
• Superregenerative 27MHz receiver
  
• 49MHz walkie-talkie
  
• Convert 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radio
  
• Vibrating pocket bug detector
  
• 2MHz RF Oscillator
  
• 50-150MHz Overtone Oscillator
  
• Simple Op-Amp Radio
  
• UHF - 100W Transistorized amplifier
  
• 50MHz Converter
  
• RF front-end for triple conversion GPS receiver
  
• 2M - 20M transverter
  
• Improved CMOS RF PLL sythesizer
  
• Harmonic oscillator
  
• Direction finder system
  
• One transistor regenerative receiver
  
• Synthesized HF receiver
  
• TBA120 narrowband FM receiver
  
• TDA7000 receiver
  
• ZN414 receivers
  
• 10W HF linear amplifier
  
• 500W HF linear amplifier
  
• 3W HF QRP linear amplifier
  
• Phasing SSB exciter
  
• 500mW HF linear amplifier
  
• Generic VHF power amplifier
  
• 10.7MHz FM detector
  
• RTTY terminal unit
  
• Q-multiplier
  
• CMOS RF PLL sythesizer
  
• 3W FM Transmitter
  
• Crystal radio
  
• Op-Amp Radio
  
• Car radio tunes the Amateur Bands
  
• Crystal set that requires no antenna
  
• 80m Direct Conversion Receiver
  
• A compact L-match ATU for portable use
  
• Morse Adaptor for your VHF/UHF FM rig
  
• An end-fed antenna, L-match coupler and resistive bridge for HF
  
• AM Broadcast Band Regenerative Receiver
  
• 50 MHz to 146 MHz Converter
  
• Hear Amateurs on your Shortwave Radio!
  
• Compact 20 14 MHz direct conversion receiver
  
• Hear Amateurs on your FM Radio!
  
• RF actuated CW monitor
  
• LF to HF Converter
  
• Super 80 ultra-simple SSB receiver for 3.5 MHz
  
• Class B series modulator
  
• L-Band PHEMT LNA for GPS, Inmarsat etc
  
• Advanced VHF power meter
  
• The MRX-40 Mini Receiver
  
• 23cm Data Transceiver
  
• External antenna for the GPS-38, Magellan 2000, or Eagle Explorer GPS receivers
  
• AM Broadcast Band Active Antenna
  
• Active antenna with gain
  
• Ham Band VFO
  
• HF Signal generator
  
• Simple AM Radio Receiver & Amplifier
  
• Bug detector
  
• 175KHz inductive pulse receiver (PDF)
  
• 200-400 MHz voltage controlled oscillator
  
• AM/FM/SW active antenna
  
• RF Sniffer <.5 to >500 MHz
  
• Demodulator Schematic/Design
  
• AM BCB radio receiver
  
• Regenerative shortwave receiver
  
• 7MHz SSB Transceiver
  
• DSBSC (Double Side Band Supressed Carrier)
  
• Frequency Synthesizer
  
• Digital Automatic Gain Control (AGC)
  
• Four Channel Wireless Transmitter and Receiver
  
• Talking receiver
  
  

  

  Turn your PC into a FM radio transmitter with this amazing card. Make your own community radio or just play MP3 to an entire village with PCI MAX 2005.

  
  
  
• PLL synthesizing oscillator (1)
  
• PLL synthesizing oscillator (2)
  
• PLL synthesizing oscillator (3)
  
• 2N2222 40 Meter CW/DSB Transceiver
  
• Yaesu FT-736R doppler compensation
  
• Phased lock loop schematic
  
• 30M PSK31 Transceiver
  
• SOP receiver (PDF)
  
• SOP direct conversion receiver
  
• Receiver
  
• 30m direct conversion receiver
  
• Popcorn direct conversion receiver
  
• 40m direct conversion receiver
  
• 80m direct conversion receiver
  
• Huge LED Antenna Direction Display (part 1)
  
• Huge LED Antenna Direction Display (part 2)
  
• 136 kHz direct conversion receiver
  
• One Watt 2.45 GHz Linear Amplifier
  
• 222 MHz Transverter
  
• VFO from 2001 ARRL Handbook, page 17.74
  
• VFO from 2001 ARRL Handbook, page 14.20
  
• Assorted RF circuits
  
• 14MHz SSB 10mW Transceiver
  
• Building a Simple LF Exciter
  
• Yaesu band decoder schematic
  
• 23cm Wide-Band FM data transceiver for high-speed packet-radio
  
• VLF radio receiver schematic
  
• 5 watt, 80 meter QRP CW Transceiver
  
• How to Build a 300MHz AM, RF Remote Control System
  
• RF Modem Robotics Project
  
• PLL FM transmitter
  
• ICOM CI-V interface with RS232 RTS to PTT
  
• Improved FM Stereo Modulator
  
• Smooth Tone Clickless CW Sidetone Generator
  
• Variety of receiver converter projects
  
• One transistor FM receiver
  
• 42 Mc Band to 88 Mc Band (retrofit converter) Project
  
• Crystal radio circuits including diode performance comparison
  
• 50MHz Assistant (Preamp & Power Amp.)
  
• Bug detector
  
• Basic RF oscillator
  
• Radio Control Electric Switch
  
• 56K RF Modem
  
• 80M ARDF direction finder
  

  
  
  
  AM MAX II, 10W AM transmitter with DSP
  
  
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  Solar-powered schematics

• Sun tracking circuit for solar arrays
  
• Solar power recharger
  
• Solar power supply
  
• Solar charge controller
  
• Solar robots
  
• Solar Tracker
  
• 1381 solar engine
  
• D1 solar engine
  
• FLED solar engine
  
• PM1 solar engine
  
• Solar car array controller schematic
  
• Solar car battery monitor schematic
  
• Solar car brake controller schematic
  
• Solar car main controller schematic
  
• Solar car display controller schematic
  
• Solar car electrical design and circuit index
  
• Portable solar battery charger
  
• Sensor Electronic Tracker with H-Bridge Drive
  
• Sensor Electronic Tracker with Simple Solar Charge Controller
  
• Solar tracking control system
  
• LED7 solar tracker
  
• Solar step-down regulator
  
• Zener-based solar engine
  
• AA battery solar charger
  
• AA battery solar charger
  
• Solar Panel Charge Controller / Low Voltage Disconnect Circuit
  
• Solar Panel Current Meter
  
• SCC2 10 Amp Solar Charge Controller
  
• Solar Charged LED Flashlight
  
• AA battery solar charger
  
• Solar Panel Charge Controller / Low Voltage Disconnect Circuit
  
• Solar Panel Current Meter
  
• Solar cell Nicad charger
  
• Solar powered dock lamp flasher
  

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  Telephone and intercom related schematics

• Telephone recording circuit
  
• Infinity Transmitter Schematic and Plans
  
• Digisound ring modulator
  
• Incoming call indicator
  
• Telephone Ring Generator Using 60Hz Power Transformer
  
• Telephone Ring Generator Using Switching Power Supply
  
• Telephone In-Use LED Indicator
  
• Telephone In-Use Relay Circuit
  
• Telephone Audio Interface
  
• Telephone interfacing / caller ID using a PIC microcontroller
  
• Home made PBX / PABX
  
• Ringing Phone Light Flasher
  
• Phone Busy Indicator
  
• FM Telephone Bug
  
• Cut Phone Line Detector
  
• Simple Phone Tap
  
• Telephone Hold Button
  
• Telephone Recorder
  
• 300 baud modem circuit schematic
  
• DTMF Generator/Decoder
  
• Interface cables for various cell phones
  
• Telephone music on hold box
  
• Telephone ring controlled relay
  
• 1-line telephone status indicator (PDF)
  
• Line in use indicator (PDF)
  
• 4-line telephone status indicator (PDF)
  
• Caller ID decoder
  
• Telephone in use light
  
• Detecting a telephone RING
  
• Phone In-Use Light
  
• Phone to audio interface
  
• Phone Off-Hook Indicator
  
• 'phone rang' indicator light
  
• Phone Line to Audio
  
• Phone in-use
  
• Telephone Line Monitor
  
• Use old phones as an intercom
  
• Phone-In-Use indicator
  
• Hold function for Telephone
  
• Digital/Standard Phone Line Tester
  
• Caller ID decoder part 1
  
• Caller ID decoder part 2
  
• DTMF decoder / logger
  
• FM telephone bug
  
• Universal telephone hold
  
• Talking phone dial monitor
  
• Telephone line simulator
  
• Telephone privacy adapter
  
• Telephone ringing circuits
  
• Simple circuit to connect telephone equipment to audio mixer
  
• NCDS Interface Schematic for Nokia 3110, 8110, 8110i
  
• Assorted telephone circuits
  
• Greek telecard reader
  
• Phone ring circuit schematic
  
• Cut phone line detector
  
• Telephone autodialler
  
• Taxi phone automatic dialler
  

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  CYBER MAX FM 15W
  Meet the Cyber MAX FM; professional rack mount transmitter, backlit LCD display, digital stereo encoder, power regulation from 0 to max, stylish enclosure. Comes with a built-in power supply and requires absolutely no tuning, making this unit very easy to use!!
  
  
  
  Test equipment schematics

• Audible continuity tester
  
• Wire tracer
  
• Signal generator for signal tracer
  
• Electronic level
  
• Digital volt meter
  
• Adjustable continuity tested
  
• Frequency counter
  
• Tri-Waveform Generator
  
• 220V live wire-in-wall scanner
  
• Owens Bridge Inductance Measurement Device
  
• ESR Meter
  
• Line Output / Flyback transformer tester
  
• PC-Based Digital Storage Oscilloscope (DSOA)
  
• PC Based Digital Storage Oscilloscope Mk3
  
• Simple 6-Digit 40MHz Frequency Counter Module
  
• Automatic stud detector
  
• Capacitance meter
  
• Capacitance meter
  
• AC Line Current Detector
  
• Triangle and Squarewave Generator
  
• Signal tracer / injector
  
• Voltage probe
  
• Live line detector
  
• Grid dip meter
  
• PCB VSWR bridge
  
• Electric field & leakage detector
  
• Simple polarity detector
  
• RCM710 Electronic Scale
  
• 3 - 12 MHz Signal Generator
  
• Some simple test equipment to build
  
• RF Power Meter for the QRPer
  
• Dip Oscillator for HF
  
• Two Tone Audio Oscillator (use for SSB tests)
  
• Simple pH meter
  
• Temperature compensated pH meter
  
• pH meter with calibration
  
• Four Channel Oscilloscope Adapter
  
• Arbitrary Waveform Generator
  
• Digital Pressure Gauge
  
• Remote Field Strength Meter
  
• Digital frequency counter
  
• Function generator
  
• High / Low indicator
  
• AC/DC LED Indicator
  
• Micro ohm meter
  
• Micro volt probe
  
• MOSFET tester
  
• Power factor meter
  
• Ramp generator
  
• LASER/LED light output intensity meter (PDF)
  
• Frequency and capacitance meter
  
• Resistor decade box
  
• Simple light sensor adapter for oscilloscope
  
• Time Domain Reflectometer (TDR)
  
• 40MHz frequency counter using Atemel AVR 2312 microcontroller
  
• pH Meter
  
• Multi Wire Cable Tester
  
• Connection tester
  
• EMF field probe
  
• Function generator
  
• Logic probe
  
• Zener diode tester
  
• Mini DDS (direct digital synthesizer)
  
• LCD frequency counter (PIC16F84)
  
• Pulse Reading Logic Probe
  
• Pink Noise Generator for Audio Testing
  
• Audio Millivoltmeter
  
• Audio Test Oscillator
  
• Full Featured Transistor Tester
  
• Opamp Design and Test Board
  
• Microphone Circuit Test Oscillator
  
• Distortion Analyser
  
• Self Oscillating Amplifier for Distortion Testing
  
• 120MHz frequency counter
  
• Capacitance meter that connects to multimeter
  
• Transistor tester and signal injector
  
• Continuity tester
  
• Square wave oscillator (555)
  
• Build a Magnetic Field Immunity Tester
  
• 555 Timer IC Tester
  
• 555 go / no-go tester
  
• 12V Lead-Acid Battery Monitor
  
• Continuity tester 2
  
• Continuity tester
  
• Logic probe
  
• 4-channel DSO for oscilloscope
  
• Field strength meter for the 137 kHz band
  
• In-circuit electrolytic tester
  
• PIC logic probe with pulser
  

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  ARRL handbook, the holy bible of RF, a complete and extensive guide to radio frequency circuits and electronics in general (link goes to 2004 version)
  
  
  Timing, oscillators etc. (schematics)

• Budget timer
  
• Long period timer
  
• 555 time delay circuit
  
• Low frequency clock
  
• Countdown timer with relay
  
• DDS using AD9835
  
• 1 Second Time Base From Crystal Osc.
  
• Power-On Time Delay Relay Circuit
  
• Low Voltage , High Current Time Delay Circuit
  
• Power-Off Time Delay Relay Circuit
  
• Generating a Delayed Pulse With a dual 555 Timer
  
• 1KHz Sinewave generator
  
• Timed beeper
  
• GPS receiver clock circuit
  
• Time Delay Relay
  
• Time Delay Relay
  
• Wide-swing Variable Crystal Oscillator
  
• Circuit that momentarily closes a pair of contacts at long intervals
  
• Onboard Fogger Timer
  
• Colpitts 1 to 20 MHz Crystal Oscillator
  
• Divide By 1-1/2 Circuit
  
• Simple sinewave generator
  
• Two Transistor Sine Wave Oscillator
  
• 10 Hz to 10 Khz VCO with Square and Triangle wave
  
• Line powered 60Hz clock generator (PDF)
  
• Micro-power pulse generator (PDF)
  
• Darkroom camera shutter timer
  
• Divide by 1.5 counter (PFD)
  
• High-output square wave generator (PDF)
  
• D Flip-flot one-shot circuits (PDF)
  
• Clock divider
  
• Clock doubler
  
• CMOS oscillator
  
• Crystal 32.768KHz CMOS Oscillator
  
• Crystal oscillator
  
• Cheap 40KHz clock
  
• Stable 40KHz clock
  
• 'Rounding Off' a square wave
  
• Switch debounce using 555
  
• Square wave to sine wave converter
  
• Day / Night / 24 Hour Select Sensor
  
• One transistor timer
  
• Variable timer
  
• Micropower pulse generator (PDF)
  
• Square wave oscillator
  
• Triangle wave oscillator
  
• Sawtooth wave oscillator
  
• Sine/Cosine wave oscillator
  
• 555 timer
  
• 555 oscillator
  
• Stable multivibrator (IC)
  
• Stable multivibrator (Transistor)
  
• Timer based on Microchip PIC16F628
  
• Push Button Switch Debouncer
  
• Square wave oscillator
  
• 5 to 30 Minute Timer
  
• NE555 Basic Monostable
  
• Mini DDS (Direct Digital Synthesis)
  
• Astable Multivibrator
  
• High Precision GPS/TV controlled Reference Oscillator
  
• TV based Receiver for a Standard Frequency Generator
  
• AD9852 DDS schematic
  
• A GPS receiver based frequency standard
  
• Monostable multivibrator
  
• Clock generator
  
• 555 Timer Tutorial + Circuits
  
• Versatile electronic timer
  

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  Transmitter schematics (also see RF)

• Li'l 7 AM Transmitter Schematic
  
• Wireless microphone
  
• XTAL locked tone transmitter
  
• AM oscillator for wireless microphones
  
• Wireless microphone
  
• 1W CW Transmitter
  
• 433MHz transmitter using SAW resonator
  
• A 3m (100 MHz) small bug
  
• Basic FM Transmitter
  
• Micro Power AM Broadcast Transmitter
  
• FM Beacon Transmitter (88-108 MHz)
  
• 1 valve CW transmitter
  
• 250mW HF CW transmitter
  
• 2 valve CW transmitter
  
• Transmitter using LM317
  
• 5 Watt HF CW transmitter
  
• Simple FM microphone
  
• FM bug
  
  
  300W amplifier for your FM transmitter, don't let the big boys bully you!
  
  
  
  
• High power FM bug
  
• 27MHz AM/CW transmitter
  
• Easy 2-meter transmitter
  
• QRP HF transmitter
  
• Spark gap transmitter
  
• QRP SSB transmitter
  
• Crystal controlled FM transmitter
  
• 150mW FM transmitter
  
• FM transmitter
  
• Two Valve 40m CW Transmitter
  
• Frequency agile 80m CW QRP transmitter
  
• 80 metre DSB transmitter
  
• One Valve CW transmitter
  
• Simple Low FER Transmitter
  
• 7Mhz AM/CW Amateur Radio Transmitter
  
• VHF FM transmitter
  
• Simple FM transmitter
  
• Wireless microphone
  
• Shortwave radio transmitter
  
• 175KHz inductive pulse transmitter (PDF)
  
• 7MHz QRP transmitter
  
• Small Radio Transmitter
  
• FM Telephone Transmitter
  
• Tracking transmitter
  
• 5W PLL Transmitter
  
• Miniature FM transmitter
  
• Sensitive FM transmitter
  
• Simple RF transmitter
  
• 1.5 volt tracking transmitter
  
• Tracking transmitter
  
• Micro Power FM Broadcasting Circuits
  
• Low Power FM Transmitter
  
• RF/SS Handie Hopper Transmitter Schematic
  
• 30-Meter QRP Transmitter for Morse Code
  
• Miniature FM Transmitter #1
  
• Miniature FM Transmitter #2
  
• Miniature FM Transmitter #3
  
• Light sensing RF transmitter
  
• Micro-Spy with FETs
  
• Micro-Spy with USW
  
• Micro-Spy with TTL
  

CYBER MAX FM 15W
Meet the Cyber MAX FM; professional rack mount transmitter, backlit LCD display, digital stereo encoder, power regulation from 0 to max, stylish enclosure. Comes with a built-in power supply and requires absolutely no tuning, making this unit very easy to use!!



300W amplifier for your FM transmitter, don't let the big boys bully you!


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Video related schematics

• Video Clock Superimposer
  
• Video clock superimposer using PIC16C711
  
• Simple AV (audio / video) wireless transmitter
  
• Audio / video distribution amplifier
  
• 10GHz video link
  
• Experimental macrovision remover
  
• 8 x 8 Audio-video switch
  
• VHF/UHF TV modulator
  
• LH0032 video amplifier
  
• LM359N video amplifier
  
• Macrovision code remover
  
• Driver for multiple VGA monitors
  
• CCD (charge coupled device) support board
  
• Closed-Caption Decoder
  
• PIC-Tock video clock
  
• Video/Audio Wireless Transmitter
  
• Video signal amplifier
  
• RGB video digitizer
  
• Color Bar Generator
  
• Microcontroller test pattern generator
  
• NTSC Video Distribution Amplifier
  
• Commodore RF modulator
  
• Video signal edge enhancement
  
• Video amplifier
  
• Video/Audio Wireless Transmitter
  
• 4 Stage 555 Timer for Video Cam Control
  
• Digital volt meter with video output
  
• TV/Radio antenna cable galvanic isolator
  
• S-video to composite video adapter
  
• VGA converter for video projectors and fixed frequency monitors
  
• VGA to TV converter
  
• VGA to PAL and NTSC converter
  
• PIC micro frame grabber (TDA8708)
  
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CYBER MAX FM 15W
Meet the Cyber MAX FM; professional rack mount transmitter, backlit LCD display, digital stereo encoder, power regulation from 0 to max, stylish enclosure. Comes with a built-in power supply and requires absolutely no tuning, making this unit very easy to use!!