Misc audio (also see Music, Amplifiers, Preamp)

· Pink noise generator

· A Schottky-based Saw-to-Tri converter

· Saw to triangle converter

· Improved saw to triangle converter

· Voltage controllable LFO

· White noise generator

· Electronic siren

· Two-tone siren

· Underwater microphone

· Code practice oscillator

· Noise generator

· Electronic whistle

· Low Frequency Sinewave Generators

· Horror movies sound effects

· Sound amplifier

· Temperature sensitive oscillator

· 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

· Ultrasound detector

· 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

· NHT subwoofer amp

· 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

· Fender Champ Replica

· Keyboard scanned 8-tone generator

· Audio test station

· Audio tone VU meter

· Pink noise generator

· 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

· 110 dB beeper - 74C14

· Audio output level meter

· Surround Sound Decoder Mk2

· Stereo compressor

· Audio mixer

READ MORE - Misc audio (also see Music, Amplifiers, Preamp)

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

· Simple RS232C Level Converter using Transistors

· 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

· Atmel 89C Series Flash Microcontroller Programmer

· AT89C2051 real-time controller

· PIC12C508 Night-light saver

· AT89C2051 Night light saver

· Atmel 8051 Flash Based-Microcontroller Programmer

· AT89C2051 Digital thermometer and clock

· PIC16F84 CW decoder (PDF)

· 12C508 Smart Lock

· Build a PIC controlled DDS VFO, 0 to 6 MHz

· PIC controlled DDS VFO, 0 to 6 MHz

· Basic Stamp Lightning Activity Monitor

· TCP/IP stack and WWW server in a PIC16F84

· 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

· Programmer PIC16F84,12C50x and EEPROM 24Cxx

· RDS Encoder - digital part

· PIC programmer for serial port

· PIC 18 programmer (PIC18F458, PIC18F452, PIC18C252, PIC16C745, PIC18F6620, PIC18F6720)

· Freign vocabulary recollector

· 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

· 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

· PIC18 Schematic

· PIC16C71 morse code callsign generator

· Atmel AVR programmer

· Microchip PIC ICSP implementation

· 101 AT Keyboard to ASCII Decoder using 68HC705J1A MCU

· DTMF tone decoder using Basic Stamp

· LCD Serial Terminal

· Propellor clock (PIC16F84)

· World's smallest PIC programmer

· PIC X1 schematic (PIC16F877)

· Optical sensor using PIC12C508

· Interfacing S-7800A to PIC16F877

· A Scenix (and PIC) Programmer

· MMC to PIC16F876 circuit diagram

· 8088 maximum mode SBC

· EZ80 single board computer schematic (Z80)

· Voice recording and message retrieval system

· 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

· 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

· AT89C2051 line-follower robot

· Night light saver (PIC12C508)

· Basic stamp interface circuits

· PIC16F84 sound controlled Christmas lights

· 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

· PIC16C84 VT-52 Emulator for Linux

· Microchip PIC ICD (in-circuit debugger)

· Tony Nixons Pocket Programmer (PIC)

· PicoWeb V5.1 (AT90S8515) tiny web server

· 8051 Development System Circuit Board

· 8051 Development System Circuit Board

· Temperature controlled based on AT89CX051

· 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

· PIC16F628 based timer

· Ser-Key 10-Key Serial Keypad Encoder

· 2-wire LCD interface using PIC16CF84

· PIC16F84 Serial I/O-expander with PicBasic

· RS 485-RPT Schematic

· AC lamp dimmer for Basic Stamp

· Microcontroller multi channel light dimmer

· PIC16C63 MIDI controlled light dimmer

· No parts PIC micro programmer

· Connecting LED to PIC Micro I/O pins (PDF)

· Microprocessor RS-232 Reset

· AT90S8515 experimenter board

· A PIC-Based Keyboard Emulator

· PIC-based robot

· ScanMate audio activated recorded

· PIC18F252 bootloader schematics

· PIC16F876 Datalogger

· GPS Repeater

· Kodak DC-20 camera interface (PIC12C509)

· Kodak DC-20 camera interface (PIC16F84)

· Remote control for Raymarine ST4000 Autopilot

· PIC programmers for parallel port

· Wisp628 ISP Microchip PIC Programmer

· 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

READ MORE - Microcontroller based schematics

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

· Heart rate monitor

· ECG amplifier

· Simple lie detector

· 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

· PC-based biofeedback monitor

· Pain field generator

· The ESP SIM (Sound Impairment Monitor)

· Respiration system

READ MORE - Medical and health related schematics

Lighting schematics

· Garden light switch

· DMX lighting and special effects

· Microcontroller Multichannel Light Dimmer

· Digital timer light switch

· Flashing flashlight

· Flashing road baricade for construction workers

· Hand clap lamp control

· 600W 120VAC lamp dimmer

· 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

· Smart 12V light dimmer (PDF)

· 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

· 10-channel follower for Austin Hotel

· 12V Color organ and reverb unit

· 8-bit digital firing circuit

· Audio trigger circuit for light chasers

· Christmas star

· Electronic candle

· Electronic candle V2

· Fluorescent light dimmer

· Strobe light

· LED Mood Light

· LX-800 Lighting system

· Xenon Strobe Light

· Lamp flasher/dimmer

· Efficient dc lamp dimmer - 74C14

· Instrument panel lamp dimmer control

READ MORE - Lighting schematics

LED related schematics

· LED Flasher

· LED pulser with audible output

· IR Illuminator

· Flashing Christmas LED display

· ICL7660 LED flasher

· Variety of LED circuits

· Winking LEDs

· LED flashing light

· LED initials

· 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

· LED Stroboscope - Maintains constant brightness at all flash rates

· White LED circuits

· Assorted LED circuits

· LED Mood Light

· LED Audio VU Meter

· Scrolling LED sign

· LM3909 LED flasher

· Animated LED signboard (PIC16C84)

· Picxie 2 - 8x8 Animated LED Signboard

READ MORE - LED related schematics

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

· Simple laser communicator

· LASER listening device

· LASER transmitter / receiver

· RS-232 Laser Transciever

· HeNe laser power supply schematics

· 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

· 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

· Diode Laser Power Supplies

· Ar/Kr Ion Laser Power Supply Design

· Laser light show

· Laser light show pattern generator

· Simple laser communicator

READ MORE - Laser related power supplies and data transmission

Infrared

· IR detector

· Infrared body heat detector

· Stereo IR audio receiver

· General purpose IR receiver

· Wireless IR headphone transmitter

· Wireless IR headphone receiver

· USB to infrared adapter

· 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 remote control system for PC

· IR Receiver (Amplitude Modulated IR)

· IR Transmitter for Audio (Amplitude Modulated IR)

· Digibox interface

· IR remote control

· IR remote control jammer

· Long Range Infrared Remote

· LCD + IR circuit schematic

· 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

· 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

· Infrared repeater

· 40khz IR Tester

· 555 timer 40khz IR Oscillator

· IR detector / emitter

· Fire-Stick infrared remote control

· Simple infrared remote control

· Infrared / Ultrasonic beacon

· Infrared transmitter / decoder

· Infrared logic probe

· Implementing Infrared Object Detection

· IR detector for robotics

· Computerized Infrared Remote

READ MORE - Infrared