Dark-Activated 230V Lamp:  Compact circuitry using small-size parts only.  Can be wired in parallel to existing switches. (added 6/06)

DC Motor Control Circuit:  Here, S1 and S2 are normally open , push to close, press button switches.  The diodes can be  red or green and are there only to indicate direction. You may need to alter the TIP31 transistors  depending on the motor being used. Remember, running under load draws more current.  This  circuit was built to operate a small motor used for opening and closing a pair of curtains. As an  advantage over automatic closing and opening systems, you have control of how much, or how  little light to let into a room.  The four diodes surriunding the motor, are back EMF diodes. They  are chosen to suit the motor. For a 12V motor drawing 1amp under load, I use 1N4001 diodes... (added 2/06)

DC Motor Control using a Single Switch:  (electronic Circuit / Schematic added 10/04)

DC Motor Controller #2:  This DC Motor Controller circuit will control a 12V dc motor. The system will have three pushbuttons: a START button, a REVERSE button and a STOP button. Initially, the motor must not be running. When the START button is pressed, the motor will run in one direction. (added 6/06)

DC Motor Driver with L6203:  (electronic circuit added 4/05)

DC Motor Driver with L6204:  (electronic diagram added 4/05)

DC Motor Driver with L6206:  (electronic design added 4/05)

DC Motor Pulse Width Modulation Speed Control:  This is a circuit for controlling the speed of small DC motors, it works nicely as a speed controller for an HO or N gauge model railroad. (electronic diagram added 10/06)

DC Motor Reversing Circuit #2:  A DC motor reversing circuit using non latching push button switches. Relays control forward, stop and reverse action, and the motor cannot be switched from forward to reverse unless the stop switch is pressed first. (added 4/02)

DC motor speed controller:  (circuit / design added 10/06)

DC Motor-Driver H-Bridge Circuit (circuitdb):  Physical motion of some form helps differentiate a .... (added 2/07)t from a computer. It would be nice if a motor could be attached directly to a chip that controlled the movement. But, most chips can't pass...

DC Motor-Driver H-Bridge Circuit:  (electronic circuit added 2/07)

DC Push Button Motor Control Circuit:  (circuit / schematic design added 6/06)

DC servomotor controller:  An experiment on the DC servomotor control system. It is controlled with only an AVR.  (added 6/06)

Debugging an MCU-based CCD camera controller:  Agilent Application Note   (app note added 6/06)

Decoding Infrared Remote Controls:  (circuit added 7/02)

Design Guidelines for Compactpci Hot Swap Control Applications using the LTC1644:  Design Solutions 12  Design Notes (Linear Technology)  (app note added 2/06)

Digi Pack DMX 512 Lighting Controller:  (electronic circuit added 4/05)

Digital Automatic Gain Control (AGC):  (electronic circuit added 7/03)

Digital Remote Thermometer:  Remote sensor sends data via mains supply Temperature range:00.0 to 99.9 °C (added 9/04)

Digital Speed Control for RC Car:  DC motor PWM controller that takes the1ms to2ms pulse from the RC receiver and converts it into a PWM train at1Khz (added 6/06)

Digital Speed Control with Reverse:  (Schematic added 10/06)

Digital Speed Control:  Digital Speed Control with aSwitching rate of 15KHz (circuit added 10/06)

Digital Volume Control has Log Taper:  04/11/02 EDN Design Ideas  /  (added 1/05)  Digital potentiometers provide a compact and convenient way to attenuate audio-amplifier signals. However, most such potentiometers suffer from at least one flaw: a nonlogarithmic step increment. To avoid this problem, a user must usually step the potentiometer in a nonlinear sequence to simulate a logarithmic taper. ...

Digital Volume Control:  This circuit could be used for replacing your manual volume control in a stereo amplifier. In this circuit, push-to-on switch S1 controls the forward (volume increase) operation of both channels while a similar switch S2 controls reverse (volume decrease) operation of both channels.  A readily available IC from Dallas semiconductor, DS1669 is used here.….  (added 10/05)

Digitally Addressable DALI Dimming Ballast App.:  Microchip Application Note Published 10-Apr-02   (app note added 6/06)

Digitally Addressable DALI Dimming Ballast:  (circuit / schematic design added 6/06)

Digitally Control Room Light Intensity:  11/11/04 EDN Design Ideas  / (added 6/06)  Many people favor different light and temperature settings for different rooms depending upon their mood or whether they are working or relaxing. The circuit in Figure 1 controls the intensity of the artificial light in a room and monitors the temperature of two zones. The two main circuit blocks are the PIC16C67 master controller and the ADT7516 temperature-sensor interface, which includes a ...

Digitally Controlled Dimmable Lighting:  This project implements the control of 2 lighting sets using a PIC18F252 microcontroller. The advantage of the digital controller is its increased flexibility. The brightness of the light sets are controlled using phase angle firing method, but with the intention of investigating the implementing of a burst firing method. (added 6/06)

Dimmer Circuit for Normal Light Bulbs:  (schematic / circuit design added 9/02)

Dimmer/Motor Speed Control:  (electronic circuit added 7/03)

Disco Light Controller:  (circuit / schematic design added 6/06)

Discrete Component Motor Direction Controller:  (electronic circuit added 10/05)

DMOS 3A, 55V, H-Bridge:  National Semiconductor Application Note   (app note added 6/06)

Dome Lamp Dimmer:  (electronic circuit added 7/03)

Dome Light Dimmer for Cars:  This unique circuit makes your dome light look cool. Usually when the car door is closed, the dome light just goes OFF. With this circuit, you can have our dome light fade slowly in brightness and finally go OFF. This slow dimming of the light gives a very good feeling at night. It looks very romantic!....   (added 10/06)

Dual Channel Servo Pulse to H-Bridge Interface (~mixos):  (electronic circuit added 2/07)

Dual Channel Servo Pulse to H-Bridge Interface:  (circuit / schematic design added7/06)

Dual DC-Motor-Speed Controllers Navigate Robots:  03/29/01 EDN-Design Ideas / (added 2/06)

Dual Fan Controller:  A birthday present gone too far. An overengineered temperature-based automatic twin fan controller with brass face to keep a kitchen PC cool.  (project added 10/06)

Dual Polarity Amplifier has Digital Control:  09/12/96 EDN-Design Ideas / (added 2/05)  

Dual Slope-Sampling Solar Engine:  Voltage-Controlled Solar Engine: The dual slope sensing SE is another Wilf Rigter design; this SE is optimized for 'bots with a low-power standby mode.   (added 6/06)

Eight Channel Eight Bit PWM Controller:  National Semiconductor Application Note   (app note added 6/06)

Eight Way Switcher:  (Schematic / Circuit added 10/06)

Electric Curtains Control:  This hybrid circuit uses a mixture of transistors, an IC and a relay and is used to automatically open or close a pair of curtains. Using switch S3 also allows manual control, allowing for curtains to be left only partially open or closed. The circuit controls a motor which is attached to a simple pulley mechanism, to move the curtains. I first started this circuit over 20 years ago and apart from now using metal gears, very little has changed.
(added 11/05)

Electric Power Controller:  suitable as dimmer for100-Volt lamp up to1200W (app note added 6/06)

Electrical Equipment Control using PC:  (electronic Circuit / Schematic added 10/04)

Electronic Fluorescent Lamp Ballast:  International Rectifier application note in PDF format (added 4/02)

Electronic Motor Starter:  (circuit / schematic design added 6/06)

Electronic SPDT controls two PCs:  09/2/99 EDN Design Ideas /  (added 2/06) 

Electronic Speed Controler for R/C Models:  Here's how you can make an electronic speed controler (ESC) for your remote control car, boat or even an airplane using an old servo and some MOSFETS…. (electronic design added 10/06)

Electronic Thermostat Relay Circuit:  (electronic schematic / circuit added 4/02)

Emergency Backup Lamp:  (electronic circuit added 7/03)

Encoder and PC Make Complete Motor Control System:  12/12/02 EDN Design Ideas  /  (added 1/05)  This Design Idea combines a simple ISA-bus-resident interface circuit; a garden-variety PC; a high-resolution optical shaft encoder; and a PWM-controlled, 0.05-hp, brushed, permanent-magnet dc motor to make a high-precision and high-power motion-control system. The system sequences the precise rotation of an evacuated steel bell jar several feet in diameter, such as those used in molecular-beam......

Energy Management Control System:  Microchip Application Note Published 26-Aug-97   (app note added 2/06)

Engine Control Unit Schematics:  (diagram added 6/03)

Fan Control Advances: Consider Fan Regulation:  App Note 896: Maxim IC  (application note added6/06)

Fan Controller Adapts to System Temperature:  09/25/97 EDN-Design Ideas /(added 4/05)   -The circuit adjusts a fans speed according to temperature.

Fan Speed Control is Cool!:  App Note 1784: Maxim IC  (application note added6/06)

Fan Timer Based on Motorola 68HC908QT2:  (electronic circuit added 4/05)

Finite State Machine Programmable Logic Controller:  Finite State Machine based Programmable Logic Controller.  7 Inputs   8 Outputs   Simple IF/THEN/ELSE based compiler language generates direct EPROM files…. (add 11/05)

Fire Stick infrared Remote Control:  (circuit / schematic design added 6/06)

Fluorescent Desk Lamp:  This circuit will power a 6 inch4-Watt fluorescent tube off a12 volt supply, consuming300 mA. It may also be powered by a suitably rated universal AC/DC adapter. (added 11/05)

Fluorescent Lamps Ballasts and Fixtures:  (circuit / schematic added 5/03)

FM RF Remote Control (88-108 MHz):  1KM Range  (added 6/06)

Fogger Smoke Machine:  (design circuit added 8/02)

Force/Sense Connection Eliminates Multiplexer on Resistance Error:  01/22/04 EDN Design Ideas  /  (added 1/05)  Digitally controlled gain is an everyday analog-design element. You frequently find this element in an op-amp-based, transimpedance current-to-voltage converter. When you design digital gain control into such a converter, the usual scheme is to arrange things such that a digital multiplexer selects the appropriate feedback resistor for each gain figure....

Four Channel RF Remote Control:  (electronic circuit added 4/05)

Four Way Switcher #2:  (Electronic Schematic added 10/06)

Four Way Switcher:  (Schematic added 10/06)

Four-Speed Fan Control using Simple Remote Diode Temperature Sensor:  National Semiconductor Application Note   (app note added 6/06)

Gasoline generator automatic throttle Controller:  (circuit / schematic design added 6/06)

General Purpose Display Controller:  This is a general purpose display controller for small microcontrollers. It will be used for various use because it is easy to change its configuration through using a CPLD.  (added 6/06)

GIC Resonator has Inherent Amplitude Control:  08/22/02 EDN Design Ideas  /  (added 1/05)  The circuit in Figure 1 is based on a classic GIC (generalized impedance converter). The sine-wave-oscillator circuit has inherent amplitude stabilization and normally operates from dual power supplies. However, if you connect an additional resistor, RCC, to VCC, you can operate the circuit with one supply (with VEE=0V)....

Ground Rules for High Speed Circuits:  AN-214 Analog Devices Application Note   (app note added 6/06)   Layout and Wiring Are Critical in Video Converter Circuits.

Grounding for Low-and-High-Frequency Circuits:  AN-345 Analog Devices Application Note   (app note added 2/06)