Control_Circuits
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.
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
Automatic Control Starts Loads Softly: 10/13/94 EDN-Design Ideas
Automatic Power off Circuit Saves Battery: 12/05/96 EDN-Design Ideas
BangBang Thermostat is Simple & Efficient: 11/06/97 EDN-Design Ideas
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 Betw1een 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 tw1o-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
Combination Controlled, Fully Customizable RF Remote Control:
Computerized Infrared Remote: control your stereo, TV and VCR from Windows, includes schematic and softw1are
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 tw1o Switches: a light or lights can be controlled by more than1-switch
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...
DIY Wavemaker: controls tw1o electric water pumps
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
Electronic Fluorescent Lamp Ballast: International Rectifier application note in PDF format
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.
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)..
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...
Infrared Interface With Windows CD Softw1are: 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 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 Tester #1: measures the relative intensities of different Infrared light sources
Infrared Remote Home Control: softw1are 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 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
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.
.
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
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.
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
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
Smart Switch Cuts Transformer turnon Current : 04/23/98 EDN-Design Ideas
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 . .
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
Temperature Controller keeps IR Detector At 8?K: 06/08/95 EDN-Design Ideas
Temperature Programmer uses Digital Control: 07/18/96 EDN-Design Ideas
Temperature Sensitive Oscillator: Temperature controlled based on AT89CX051
Thermo Cooling Fan: fan controller, which controls fan based on temperature
Traffic Light Controller: controls on3 LED traffic light sequence
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
