Control Circuits

0 to 10 Volt Control for RC Servos:

12 Volt Strobe Circuit: this circuit uses12V DC instead od mains AC. This is very good idea if you dont want to mess with direct mains voltage connected circuit or you want to run the stroboscope from batteries.

12 Volt Sump Pump Control:

2 wire Remote Microphone Amplifier :

300 MHz AM, RF Remote Control System:

Adaptive Windscreen Wiper Control:

Analog switch lowers relay power consumption: 12/20/2001 EDN - Design Ideas / Designers often use relays as electrically controlled switches. Unlike transistors, their switch contacts are electrically isolated from the control input. However, the power dissipation in a relay coil may render the device unattractive in battery-powered applications. You can lower this dissipation by adding an analog switch that allows the relay to operate at a lower voltage (Figure 1). .

Audio Level Control Device: compressor circuit based on LED and photodiode

Auto Trigger Circuit for Light Chasers:

Automated Traffic Signal Controller:

Automatic Control Starts Loads Softly: 10/13/94 EDN-Design Ideas

Automatic Power off Circuit Saves Battery: 12/05/96 EDN-Design Ideas

BangBang Heater:

BangBang Thermostat is Simple & Efficient: 11/06/97 EDN-Design Ideas

BASIC Stamp Thermoelectric Cooler 1:

BASIC Stamp Thermoelectric Cooler 2: 12/07/00 EDN-Design Ideas / PDF contains multiple circuits - scroll to find the one of interest

Battery Saver: Worth the effort!

Boost Converter Controls 12 Volt Fan From 5 Volt Supply: 12/12/97 EDN-Design Ideas / Temperature-controlled PWM boost converter allows operation of a12V brushless dc fan from a5V supply

Build a precision deadband circuit: 02/20/03  EDN-Design Ideas / Deadband circuits find applications in servo-control systems. A precision current source and a half-wave inverting rectifier form a positive deadband circuit (Figure 1). The REF01, IC1, is a precision 10V voltage reference. It forms a precision current source with the addition of a unity-gain buffer (IC2A) and resistor R1...

Build a UPS for USB devices: 04/11/2002  EDN - Design Ideas / Portable systems often include circuitry that derives power from an external source, such as USB. When the system disconnects from the USB supply, a battery takes over and supplies current via a dc/dc converter. A diode-OR connection (Figure 1.

Circuit Automates Switch over Between Battery & Source: 12/12/97 EDN-Design Ideas

Circuit generates fan speed control: 03/21/2002  EDN - Design Ideas / Fan noise is becoming a significant issue as electronic equipment increasingly enters the office and the home. Noise is proportional to fan speed, and the airflow hence, fan speed necessary for cooling is less at low ambient temperatures. Because ambient temperature is lower than the upper design point most of the time, a fan can run slower, making it easier on the ears.

Circuit manages power up sequencing: 10/31/2002  EDN - Design Ideas / Power sequencing poses a unique problem in power management. Because improper sequencing may cause damage to many types of processors, power-up sequencing of these devices is critical. Devices that may require power-up sequencing control include FPGAs, ASICs, and DSP chips. These devices can require tracking I/O and core voltages..

Circuit measures currents in dc servo motor: 12/06/2001 EDN - Design Ideas / The simple circuit design in Figure 1 lets you measure all components of a current flowing in a dc servo motor. The rectified output of the circuit uses ground as a reference, so you can measure the output by using a single-ended A/D converter. The current-sense resistor, R1, has a value of 0. .

Circuit protects system from overheating: 11/08/2001 EDN - Design Ideas / The two-chip circuit in Figure 1 provides fan control and overtemperature warning and shutdown signals to protect systems from excessive heat. The circuit monitors the temperature of the pc board and the die temperature of a CPU, an FPGA, or another IC with an on-chip temperature-sensing transistor. .

Circuit provides bidirectional, variable speed motor control: 05/16/2002  EDN - Design Ideas /  During the development of systems that include small motors, a simple, bidirectional motor controller with speed adjustment may be helpful. Figure 1 shows such a controller. The circuit uses everyday components whose tolerances and ratings are unimportant as long as they sustain the required voltage, current, and power..

Circuit provides Class D motor control: 05/01/03  EDN-Design Ideas / Class D audio amplifiers provide a dual benefit for battery-powered portable devices. They enhance battery life, and they produce much less power dissipation than do their linear cousins. Those features make Class D amplifiers ideal candidates for controlling speed and direction in small electric motors....

Circuit provides laser diode control: 09/19/2002  EDN - Design Ideas / Laser diodes are sensitive to ESD, rapid turn-on currents, and overvoltage conditions. To address those problems, the simple laser-diode controller in Figure 1 has several functions. The first part of the circuit comprises an 8.2V zener diode, D1 that forms the heart of a constant-voltage source for the laser diode..

CMOS Gate implements Reverse Phase Control: 05/21/98 EDN-Design Ideas

CO2 Controller for Planted Tanks:

Combination Controlled, Fully Customizable RF Remote Control:

Computerized Infrared Remote: control your stereo, TV and VCR from Windows, includes schematic and software

Constant Temperature Circuit:

Controller IC and one shot form resonant controller: 11/28/2002  EDN - Design Ideas /  Resonant power supplies are popular because of high efficiency, low noise, and compactness. You can implement a resonant buck or boost converter using a single switch. The regulation of the output in such a converter derives from using a constant on or off time and a variable frequency. The UC1864 controller IC (Texas Instruments, www..

Controller Provides Closed Loop Temperature Regulation: 05/08/97 EDN-Design Ideas

Controller Provides Constant Power DC Load: 03/14/96 EDN-Design Ideas

Controller Provides Multiple Alarm Driver Formats: 01/15/98 EDN-Design Ideas

Controlling a Light With Two Switches: a light or lights can be controlled by more than1-switch

Controlling Relays With Logic Voltages:

Controlling slew times tames EMI in offline supplies: 11/14/2002  EDN - Design Ideas / EMI from offline switching power supplies typically causes all sorts of problems for power-supply designers. You may need a large EMI filter to meet FCC emission requirements. Switchers for high efficiency produce high-frequency switching noise that can propagate through the rest of the system and cause problems..

Convert Hauppauge Infrared Remote Control to IRMAN: How to modify Hauppauge Infrared remote control receiver to work as IRMAN compatible remote control receiver. The text is in Finnish.

Correct voltage drop and phase shift in transmission lines: 03/20/03  EDN-Design Ideas / Many precision test-and-measurement and high-speed analog applications require an exact targeted voltage to be delivered to the device under test or intended load to accurately analyze the device. Design and test engineers are well-aware that this goal is sometimes unattainable, because the impedance across the traces delivering the signal to the load alters the original signal...

Decoding Infrared Remote Controls:

Digital Automatic Gain Control (AGC):

Dimmer/ Motor Speed Control:

DIY Wavemaker: controls two electric water pumps

Dome Lamp Dimmer:

Dome Light Dimmer for Cars: 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.

Dome Light Dimmer using Mic4680 Switching Regulator: simple circuit which outputs +5-Volt

Dome Light Dwell Extender / Dimmer : allows you to dim your dome light and keeps the dome light of your automobile on after you close the door

Electrical Equipment Control using PC:

Electronic Fluorescent Lamp Ballast: International Rectifier application note in PDF format

Electronic level :

Electronic Thermostat Relay Circuit:

Electronic Thermostat:

Emergency Backup Lamp:

Engine Control unit Schematics:

Fluorescent Ballast: Design uses Passive PFC and Crest Factor Control. Also available in PDF format

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.

Fluorescent Lamps, Ballasts, & Fixtures:

Fogger Smoke Machine:

GIC resonator has inherent amplitude control: 08/22/2002  EDN - Design Ideas / 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)..

Heating System Thermostat:

High Frequency AGC has Digital Control: 05/21/98 EDN-Design Ideas

HighEfficiency Inverter Drives Compact Fluorescent : 08/19/02 Electronic Design - Ideas for Design / (added 5/03) The inverter circuit shown is designed to drive a 7-W, four-pin compact fluorescent lamp (CFL) from a 12-V dc power supply. The main features of this inverter circuit include direct-drive capability, preheat for improved startup, high efficiency, and...

IC Controlled Emergency Light With Charger:

Infra / Radio Remote Control Transmitter / Receiver:

Infrared Circuits for Remote Control:

Infrared Computer Controlled Infrared Device:

Infrared Interface With Windows CD Software: use infrared technology to remotely control a CD-ROM drive with an audio CD

Infrared Receiver for Sony Remotes: receive signals from a standard Sony remote control and send the code bytes(2) received to an RS-232 port, based on PIC16C84

Infrared Remote Control #1: will allow you to turn on any piece of equipment that operates on115 volts AC

Infrared Remote Control #2: simple circuit which controls one relay output

Infrared Remote Control Extender:

Infrared Remote Control Of your PC Is Easy!: simple device that connected to the computer serial-port enables the reception of infrared codes emitted from any commercial remote control unit and with a little Windows program the computer learns to recognize sequences and simulates key pressing or executes a program

Infrared Remote Control Repeater:

Infrared Remote Control Shutter Release System:

Infrared Remote Control Tester #1: measures the relative intensities of different Infrared light sources

Infrared Remote Control Tester #2:

Infrared Remote Home Control: software Remocon Con for Windows98 able to fire remote control signal through built in infrared port (IrDA) that is of notebook personal computer standard equipment

Infrared Switch:

Infrared Toy Car Motor Controller: enables on/off remote switching of battery operated toy cars.

Inverted bipolar transistor doubles as a signal clamp: 06/07/01 EDN-Design Ideas / A number of circuits, such as level detectors and AM demodulators, benefit from a rectifier with a low offset voltage. Silicon diodes have an offset of approximately 0.6V and do not work well in low-level circuitry. A Schottky diode is a bit better...

Isolated Driver Forms Solid State Circuit Breaker: 03/03/98 EDN-Design Ideas / This circuit allows standard TTL logic levels to safely drive a high-power dc load, circuit provides also overcurrent circuit breaker functionality

Light Controlled Switch #1: switch that will be activated by light falling on a sensor

Light Controlled Switch #2: output a control signal suitable for relay depending on the light level

Light Operated Switch: Originally published in Everyday Practical Electronics, December1995

Light Organ for Car: flashes3 low voltage lights, operates at10-25-Volt voltage, in PDF format, text in Finnish

Light Processor 434 Piano Touch Panel: circuit diagram in PDF format, check also power supply circuit diagram

Linux Infrared Remote Control (LIRC):

LM3911 Temperature Controller:

Load Switcher Draws only 6 �A: 07/04/96 EDN-Design Ideas

Long Range Infrared Remote: by Boondog Automation, gives 8-20 ft of wireless control

Microcontroller Watches, Controls AC Power: 06/22/95 EDN-Design Ideas - circuit allows an isolated microcontroller to both sense and control ac power to an externally plugged-in device

MOSFET switch provides efficient AC / DC conversion: 02/17/00 EDN-Design Ideas

Novel Circuit Controls AC Power: 01/07/99 EDN-Design Ideas / PDF contains multiple circuits - scroll to find this circuit.

OTP �C Controls Boomer Amplifier: 03/18/99 EDN-Design Ideas / PDF contains multiple circuits - scroll to find this circuit

Peltier Element Controls itself: 10/27/94 EDN-Design Ideas

PMOS Transistor Guarantees Accurate Power Up Sequencing: 03/31/03 Electronic Design - Ideas for Design / A TFT LCD panel requires three voltages: VDD, VON, and VOFF. VDD, typically 13 V, powers the video signal path. VON, usually 25 V, supplies the turn-on gate drive bias voltage for the TFT cell....

Power source is insensitive to load changes: 04/04/2002  EDN - Design Ideas / For the heating and cooling elements common in industrial systems, resistance is not a fixed quantity. These elements include such devices as positive-temperature-coefficient heaters and thermoelectric coolers. Their resistance can change more than 100% during operation, and the result is a change in power dissipation for elements receiving drive from a fixed voltage or current source. .

Precision Digital AC Power Controller:

Provide 4  to 20 MPWM Control: 09/01/98 EDN-Design Ideas / Are useful when you use4- to20-mA current-loop signals to control a PWM signal

Pushbutton Switch Controls Power Supply & �C: 09/25/97 EDN-Design Ideas

Radio Control Electric Switch:

Remote Control Encoder/decoder With PIC16C620 & PIC12C508:

Remote Control using Telephone: Here is a tele-remote circuit which enables switching "on" and "off" of appliances through Telephone lines. The circuit described here can be used to switch up to nine appliances (corresponding to the digits1 through 9 of DTMF the Telephone key-pad). The Telephone can be used to switch on or switch off the appliances also while being used for normal conversation. FAIR WARNING -- THIS SITE HAS ANNOYING POP UP ADS.

Remote Controlled a Volt Switch: Infrared Controlled AV Switch with S-Video, Composite Video, and Audio

Remote Controlled Lamp Dimmer: Here is a complete design project from Biltronix that allows you to use an off the shelf remote to control the brightness of the lights.

Remote Solar LED Light:

:

Self Powered Solar Box Furnace:

Serial Infrared Remote Controller: a simple, cheap device that can be connected to any serial port to control most components that have infrared remote controls, includes schematics for receiver and transmitter

Serial Servo Motor Controller:

Servo Pulse to Dual H Bridge: interface performs vital control functions needed for propulsion and steering of a “fighting robot”.

Servo Slew Rate Control: A circuit that limits the rate of change of a signal; a feature of this design is that the positive and negative rates can be different.

Short dc power line pulses afford remote control: 10/25/2001 EDN - Design Ideas / If you face the challenge of adding a second, independently controlled light source to an existing ceiling lamp controlled by a wall switch, you may find that stringing a second power line is impossible. First, you can replace the wall switch by the circuit in Figure 1. Pushing the on switch S1 or S2 for approximately 1 sec inserts the 12V zener diodes D1 or D2 in series with the ... .

Simple Circuit Protects HotSwap and Boost Controllers : 06/10/02 Electronic Design - Ideas for Design / The conventional boost-converter topology has the potential trap of no short-circuit protection (Fig. 1). Typically, a converter is safeguarded by placing an electronic fuse in front of it. This fuse...

Simple circuit provides motor feed control: 07/25/2002  EDN - Design Ideas / Because we needed a small grinding machine, we modified an old milling machine that lacked a control system. The table of the grinding machine needed only to move back and forth with adjustable feed. Using an existing dc servoamplifier, a servo motor, and limit switches, we devised the circuit shown in Figure 1..

Simple Emergency Sump Pump Control: Sump Pump Control for12V DC Bilge Pump

Simple Sensitive Remote Control Tester:

Smart Switch Cuts Transformer turnon Current : 04/23/98 EDN-Design Ideas

Soft Start Circuit for Power Amps:

Soft start controller is gentle on loads: 11/22/2001 EDN - Design Ideas / The control circuit in Figure 1 senses a given load and automatically soft-starts the load by synchronously adjusting the power to that load. You can also manually adjust the power delivered to the load by controlling the phase angle of the line voltage across the load. The phase-angle adjustment for every ac half cycle covers 0 to 180 . .

Solar Car Array Controller Schematic:

Solar Car Brake Controller Schematic:

Solar Car Display Controller Schematic:

Speed Control Handles Isolated –48 Volt Fans : 08/05/02 Electronic Design - Ideas for Design / Chips are available to monitor and control ventilation fans. But less common are fan controllers for telecom applications. Such fans must operate in electrically isolated environments with a supply voltage in the 36- to 72-V range. For example, the...

System monitors multiple temperatures, controls fan speed: 10/12/00 EDN-Design Ideas

T V Remote Control Blocker: This file includes also some other funny circuits

Telephone Ring Controlled Relay:

Temperature Controlled NiCad Charger:

Temperature Controlled NiCd Charger:

Temperature Controlled Ovens:

Temperature controller :

Temperature Controller keeps IR Detector At 8�K: 06/08/95 EDN-Design Ideas

Temperature Monitor:

Temperature Programmer uses Digital Control: 07/18/96 EDN-Design Ideas

Temperature Regulator #1:

Temperature Regulator #2:

Temperature Sensitive Oscillator: Temperature controlled based on AT89CX051

Thermo Cooling Fan: fan controller, which controls fan based on temperature

Thermoelectric Controller (scriptable Thermometer):

Traffic Light Controller: controls on3 LED traffic light sequence

Triac Light Controller:

Two wire Remote Microphone Amplifier :

Universal Infrared Controller for a PC: This simple circuit allows you to record any Infrared remote control signal on your PC, and then play it back. This is particularly useful if you want to control appliances such as TVs, VCRs, CDs etc. from your computer. The device simply connects to the parallel port of your PC. You can also use this circuit to analyze the waveform from any Infrared remote control. This circuit was originally published in Electronics Australia, September1998

Welch Scientific Model 2153C Stroboscope: a schematic for a typical line operated variable rate stroboscope used for the visualization of moving parts as well as rotation speed or frequency determination of rotating or vibrating machinery

Wideband AGC Amplifier As a Differential Amplifier: National Semiconductor Application Notes,10-Apr-2000

Wideband AGC has 60 DB Dynamic Input Range: 10/10/96 EDN-Design Ideas

Wireless Remote Control System:

Zilog Z80 thermostat Embedded Web Server: