Electronic Circuit Schematics - 10/24/97

* Audio / music *

100W RMS amplifier
3-way 4th Order Active Crossovers for Car Audio
100W RMS amplifier
3-way 4th Order Active Crossovers for Car Audio
4W audio amplifier
8W audio amplifier
22W audio amplifier
50W audio amplifier
Audio line isolator
Audio preamplifiers
Colour (sound) organ
Digital sample rate converter
FET Audio mixer
Graphic equaliser
Guitar fuzz boxes
Guitar phaser
Headphone amplifier
IC audio preamp
LED VU meter
Low distortion audio amplifier
Microphone preamp
MIDI passthrough circuit
Multi-Mix Headphone Distribution Amp
Offset gain module
Paradoxical sound synthesiser
Phono preamp (valve)
Push-pull class A 2A3 stereo amp (valve)
Push-pull class A amp using type 5687 dual triodes
Ring modulator
SCMS killer for DAT recorders
Signal generator
Simple colour organ
Single Ended Class A2 SV811-10 Stereo Amp
Spring reverb unit
Transistor audio preamp
Transistor organ
Voltage controlled amplifier
Voltage controlled panner

* Automotive *

Breath Alcohol Tester controlling a car ignition system
Car battery charger
Wireless Auto Tachometer

* Computer related (non PC specific) *

Centronics port D/A converter
Joystick related projects
Getting power from serial port
HDLC adaptor for Atari ST
Null printer adaptor
RS-232 port monitor
Serial port A/D converter
Serial port relay control

* Consumer electronics *

Add 200 channels to PRO-43 scanner
Casio organiser interface
Home automation project
IR remote control repeater
Sharp organiser/pocket computer to RS-232 interface
The Propeller, a mechanically scanned LED clock

* Games and entertainment *

Powerglove to serial adaptor

* Microcontroller related *

68HC11 based data-logger
Basic stamp digital thermometer
Basic stamp light direction sensing
Closed caption decoder
F1 MC68HC11F1 based microcontroller - full circuit and PCB layout
iRX 2.0 PIC based microcontroller
Serial comms to LED driver
Serial port break reset circuit
Serial to parallel converter using the AT89C2051

* Models and model remote control *

Auto Reversing Circuit for Model Trains
Constant directional lighting #1
Constant directional lighting #2
Constant directional lighting #3
Constant directional lighting #4
Dual alternating flashing light
Dual tandem flashing light
Flashing light circuit #1
Flashing light circuit #2
Flashing light circuit #3
Infrared train detector
Intelligent glowplug driver
Simple train detector
Simulate gyrating headlight

* Motor, light and power control *

Battery discharger and status check
Current sensing relay driver
Diode constant lighting
Domestic heating boiler control
Fluorescent Lamps, Ballasts, and Fixtures
Light/dark activated relay
Power-line appliance controller
PWM light bulb regulator
PWM motor speed control
Servo motor info and schematics
More servo motor info and schematics
Stepper motor control circuit
Strobe light
Tacho generator motor speed feedback
Temperature controlled nicad charger
Temperature regulator
TRIAC light dimmer
Using a solenoid activated start gate
Xenon flash and strobe page

* Oscillators and timers *

Basic RF oscillator
Clock divider
Clock doubler for CMOS logic
CW beacon keyer
IC monostable multivibrator (555)
LM3909 LED flasher
Ramp generator, VCO, tri-stable oscillator
Squarewave to sine converter
Timers: delay on energise, delay on de-energise, latch

* PC related *

Barcode scanner
CCD video capture camera - circuit on request
Collection of ASCII PC related schematics
Computer controlled IR device
Connecting an AOR AR8000 or AR2700 to an IBM PC
Connecting Sega 3D glasses to a PC serial port
Data bus monitor
Interfacing the XC6200 Series
IR receiver for serial interface
Serial port A/D converter
Several PC related circuit and information files for FTP
Simple parallel port interface
TI-Calc to PC cable

* Power supplies *

12VDC To 120VAC Inverter
12 Volt low drop-out voltage regulated power supply
Adjustable power supply
Constructing low-voltage power supplies
Dual polarity power supply
High current power supply
Low-drop regulator (postscript file)
Simple regulated supply with overcurrent trip

* RF circuits *

1.5V tracking transmitter
50MHz Assistant (Preamp & Power Amp)
Active antenna
AM radio
Broadcast- quality FM transmitter
FET dip-meter
FM transmitter
Light sensing RF transmitter
Miniature FM transmitter #1
Miniature FM transmitter #2
Miniature FM transmitter #4
Op-amp radio
RF power meter
RF sniffer
Small FM transmitter
Several receiver circuits
Simplest RF transmitter
The smallest QRP transceiver for 80 meters
Transistor tracking transmitter
Various CW and AM transmitters

* Robotics (also see Motor, light and power control) *

Mobile robot
Robot limb control system

* Security and other sensors and detectors *

Collection of ASCII infrared related circuits
Garage door hacker
Infrared active motion detector
Infrared detector
Infrared to light converter
Rain detector
Security alarm
Smart card data monitor
Smart card to PC interface
Stepper motor as an encoder
Touch switches
More touch switches
Ultrasonic movement detector
Voice controlled switch

* Science related/novelty *

An inexpensive x- ray machine
Atom expander (LED light show)
Black light (battery powered invertor)
Building a Jacob's Ladder
Circuit to show chaotic dynamics
Ion detector
Laser power supply (reported as suspect design)
HeNe and solid state laser power supplies and notes (ASCII)
HeNe and solid state laser power supplies and notes (similar to above)
Lie detector
Metal detector
Rich detector
Several nuclear physics related circuits
Solid State Tesla Coil/High Voltage Generator

* Telephone related *

Caller ID
Circuit for phreaker's 'blue box'
Circuit for phreaker's 'pearl box'
Circuit for phreaker's 'red box'
Collection of ASCII phone related circuits
Cut phone line detector
FM bug
FM telephone transmitter
Noise reduction (filter) circuit
Phone busy indicator
Phone in use circuit
Telephone hold button
Telephone recorder
Telephone recording beeper
Telephone remote ringer
Universal telephone hold circuit

* Test and measurement *

20Msps Digital storage oscilliscope
Digital tester
Digital PC Oscilloscope
Resister substitution box
TempSentry temperature sensor technical info and schematics

* Files containing many circuits *

Sci.electronics FAQ: Assorted ASCII Schematics

--- Headlight Reminder Circuit
--- Parallel Port DAC
--- Quiz-Show Indicator
--- Frequency and Capacitance meter
--- CMOS Oscillator
--- Adjustable flashing LED
--- LED Display controller
--- Info on CO2 lasers wanted (ho hum)
--- Crystal 32.768KHz CMOS Oscillator
--- Crystal Oscillator
--- FM Oscillator
--- Video amplifier
--- 'Nixie' display tubes
--- Condenser microphone hookup
--- Bringing NiCd's from the dead
--- Phase shifter circuit
--- Ultrasonic transducer oscillator circuit
--- RR LED flasher (alternating)
--- HV supply: 12VDC in, 12KV out
--- Generating -5VDC from +5VDC
--- Ground loops
--- Peltier coolers/heaters

Sci.Electronics FAQ: Repair: Misc Related Schematics (ASCII)

--- Simple High Voltage Generator
--- Adjustable high voltage power supply
--- Panasonic VCR switching power supply (PV48XX and clones)
--- Variable intensity variable frequency stroboscope
--- Jacobs Ladders
--- Introduction to Curve Tracers
--- Curve tracer design
--- Quick and dirty curve tracer
--- In-circuit tester
--- Kevin's strobe schematics
--- Inverter and trigger circuits
--- Tiny tiny invertor design