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Control Circuits

 
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Last Updated: October 24, 2017 02:54 PM

Circuits Designed by Dave Johnson, P.E.

3 Minute LED Closet LightThe circuit below is powered by three 1.5v alkaline AA cells.  With a finger tap to the pushbutton trigger switch, a cluster of 6 wide angle white LEDs is turned on.  The lights remain on for about 3 minutes, then will turn off.  The circuit’s standby current . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2010

3 Volt Low Battery Voltage FlasherThis circuit is designed to monitor two alkaline cells   (3v) that form the battery often used in portable electronic equipment. . . Circuit by David Johnson P.E.-January, 1998

3-Minute Closet LightI have a coat closet by my front door.  The thing is very dark at night and really needs some kind of illumination inside.  I could hire an electrician to install a light in the closet ceiling and then wire it to a toggle switch outside the door but that would cost me quite a bit of money. . . Circuit by Dave Johnson P.E.-December, 2011

3-Minute Closet Light #2The circuit below is powered by three 1.5v alkaline AA cells.  With a finger tap to the pushbutton trigger switch, a cluster of 6 wide angle white LEDs is turned on.  The lights remain on for about 3 minutes, then will turn off.  The circuit’s standby current is only a few microamps.  A set of fresh batteries should last at least 200 light applications.  The circuit uses a Schmitt trigger inverter and two transistors.  When the pushbutton switch S1 is pressed, the 10uF capacitor C1 is discharged. . . Circuit by Dave Johnson P.E.-November, 2010

3v Powered Super Bright LED FlasherI have posted several kinds of LED flashers over the years.   This is yet one more flasher, designed to flash any high power LED of any color.  It hits the LED with a 25ms 250ma pulse once every 2 seconds.   This works out to an average current about 3ma.  It . . . Hobby Circuit designed by David Johnson P.E.-April, 2009

3v Universal LED FlasherThis low power LED flasher circuit draws about 100ua from any DC power supply ranging from 3 volts to 24 volts.  The 1.0Hz 10ms LED pulsed current is held to a constant 10ma . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

40Khz LED Test Signal GeneratorThis 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses.  The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals. . . Circuit by Dave Johnson P.E.-February, 2002

40khz TV-VCR Light Source RepeaterThis circuit is designed to be placed directly in front of a standard TV or VCR remote.  The exiting light pulses produced by the circuit match the pulses from the remote but are about 10 times more powerful.  Using the device, the remote can operate a TV or VCR over three times the normal distance. . . Circuit by Dave Johnson P.E.-June, 2000


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

3 Band Equalizer -  Using a single op-amp this easy to make equalizer offers three ranges, low frequency, mid frequency, and high.  With component values shown there is approximately +/-20dB of boost or cut at frequencies of 50Hz, 1kHz and 10kHz.  Supply voltage may be anything from 6 to 30 Volts.  Maximum boost 20dB is only realized with maximum supply voltage __ Designed by Andy Collison

3 Channel Color Organ for a Car -  An Active Filter Design.   __ Designed by G.L. Chemelec

3 Channel IR Remote Control -  This project is a 3-channel IR remote control with 3 output relay and easy to build.  Features: CPU PIC12F629 at 4MHz crystal for Tx/Rx, 3 channel output relay, The Tx use sleep mode for saving battery power, Use Phillips RC5 protocol, distance more than 7 m, Easy circuit to build and assembly and small amount of components.  Uses RC5 protocol which is probably the most used by hobbyists, probably because the wide availability of cheap remote controls and easy to understand.   __

3 Channel RF Remote Control -  This is a 3 channel RF remote control project.  The transmitter powered by 3V battery   (coin size) range about 10 m.  This remote control I use PIC12F509 from Microchip which is a 8-pin single-chip microcontroller designed for low pin count applications with 1 K words flash memory and 41Byte SRAM and some special features such Power-saving Sleep mode, Wake-up from Sleep on pin change.   __

3 Channel-Color Organ -  An old ideabut I've had numerous requests for a good design for this __ Designed by G.L. Chemelec

3 Minute LED Closet Light -  The circuit below is powered by three 1.5v alkaline AA cells.  With a finger tap to the pushbutton trigger switch, a cluster of 6 wide angle white LEDs is turned on.  The lights remain on for about 3 minutes, then will turn off.  The circuit’s standby current . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2010

3 Volt Low Battery Voltage Flasher -  This circuit is designed to monitor two alkaline cells   (3v) that form the battery often used in portable electronic equipment. . . Circuit by David Johnson P.E.-January, 1998

3 Xenon flashings found in flash for disposable cameras -  You are going to like this project.  It costs less than $3.00, contains six BUILDING BLOCKS, re-cycles a disposable flash camera and you are going to learn a lot about electronics. 
Everyone has seen a disposable flash camera.   __ Contact: Collin Mitchell

3.3 V DSP for Digital Motor Control -  Small electromechanical drives include solenoid drives, single direction DC, bi-directional DC, or brushless DC systems and are typically sized according to their frame size and power in watts.  Digital controllers, software, and complimentary analog and digital solutions from TI can help solve most drive requirements.   __ Designed by Texas Instruments App Notes, 29-Apr-99

300 MHz AM RF Remote Control SystE - M -  If you plan to build this project, simply replace the RE-99 receiver & TX-99 transmitter with the RWS-434 & TWS-434A RF receiver & transmitter modules found HERE.  These circuits will work with any RF transmitter and receiver modules.  Due to the huge interest in this project, I have just recently finished the NEW schematics.  The older schematics were scanned and pretty poor quality.  These new ones should make it considerably easier to recognize the parts used for the project.   __ Designed by © Reynolds Electronics

300 Watt Subwoofer Power Amplifier -  There are some important updates to this project, as shown below.  Recent testing has shown that with the new ON Semi transistors it is possible to obtain a lot more power than previously.  The original design was very conservative, and was initially intended to use 2SA1492 and 2SC3856 transistors   (rated at 130W)with 200W   (or 230W) devices, some of the original comments and warnings have been amended to suit.   __ Designed by Rod Elliott  ESP

35kHz Magnetic-Radiation Remote-Control -  Short-range 35KHz operation, single-channel units; Simple circuitry, no outer antennas required __ Contact: Flavio Dellepiane, fladello @ tin.it

36 LED Chaser -  example of multiplexed display to produce a chaserled's were mounted in a circle __ Contact: P. Townshend EduTek Ltd

3A 6V/12V Solar Charge Control -  This solar charge control combines multiple features into a single design: 3A current rating, low dropout voltage   (LDO), range of voltage adjustment   (accommodates 6 & 12V lead-acid batteries), reverse polarity protection, low parts cost   ($5.90) and low parts count   (14 components).  High performance is attributed to the __ Designed by Jim Keith

3-Axis Stepper Controller -  This controller is designed to control   (3) three unipolar stepper motors at up to 35V@1.25A continuous.   __ Designed by cwtech @ infinet.com

3-Channel UHF Rolling-Code Remote Control, Pt.1 -  This high-security 3-button UHF transmitter and receiver can be used for keyless entry into homes and commercial premises and for controlling garage doors and external lighting.  Three separate outputs on the receiver can be used to activate various electrical devices such as a door strike, a motorised garage door and 230VAC lights.  Up to 16 transmitters can be used with the one receiver so it's even suitable for a small business.__ SiliconChip

3-Channel UHF Rolling-Code Remote Control, Pt.2 -  Last month we introduced our new high security remote control and got as far as completing both the receiver/relay driver and transmitter.  This month we'll put it all together and get the two parts talking to each othersecurely!__ SiliconChip

3-Channel White-LED Driver Uses Simple Circuit Step-Down DC/DC Converter -  09/13/12  EDN-Design Ideas Drive multiple LEDs with current mirrors from a single step-down converter.   __ Circuit Design by Nora Jacalan Esteves, Technor Semiconductor LLC, Pleasanton, CA

3-Minute Closet Light -  I have a coat closet by my front door.  The thing is very dark at night and really needs some kind of illumination inside.  I could hire an electrician to install a light in the closet ceiling and then wire it to a toggle switch outside the door but that would cost me quite a bit of money. . . Circuit by Dave Johnson P.E.-December, 2011

3-Minute Closet Light #2 -  The circuit below is powered by three 1.5v alkaline AA cells.  With a finger tap to the pushbutton trigger switch, a cluster of 6 wide angle white LEDs is turned on.  The lights remain on for about 3 minutes, then will turn off.  The circuit’s standby current is only a few microamps.  A set of fresh batteries should last at least 200 light applications.  The circuit uses a Schmitt trigger inverter and two transistors.  When the pushbutton switch S1 is pressed, the 10uF capacitor C1 is discharged. . . Circuit by Dave Johnson P.E.-November, 2010

3-phaseProgrammable Controller for ON/OFF Motor -  Automatic on/off controller for a 3-phase electric motor can be made with a programmable time switch.  In this case a maximum of eight time durations can be programmed.  The system has two...__ Electronics Projects for You

3rd Brake Light -  This circuit is NOT a pulser or flasher! What's so special about this circuit? Well, the first third-brake light I installed I had to pull a wire from the Third Brake Light all the way underneath the carpet to the brake-pedal-switch and I thought it would be easier to pluck the signal of both brakelights via the trunk.  Bench-test your circuit first and apply power to the circuit,  __ Designed by Tony van Roon  VA3AVR

3rd Brake Light Pulser -  Several years ago these flashers were introduced in the automotive industry as part of the third brake light and contained strobe lights   (and strobing continuously for the duration of pressing the break pedal) but got abandoned almost immediately sometime later because of the 'strobe' effect it has on some people.  This circuit has become obsolet since much better circuits are available these days without the 'lag' in between brakes caused by R4 and C3.  One of the circuits is listed below __ Designed by Tony van Roon  VA3AVR

3-Tones Controlled Relay -  Schematic only __ Designed by va3iul

3V LED Chaser -  There are many 9V chaser circuits that seem to waste about 7V when driving LEDs that are only about 2V.  This project is unique, because it uses only two inexpensive alkaline battery cells totaling 3V for power.  Since most of the waste is eliminated, the cells last a long time.  Unlike the other circuits, this one flashes the LEDs for only about 30ms each, further extending the battery life.  For user convenience, it has a stepper speed control and a brightness control.  At slower speeds and with reduced brightness,  __ Contact: IQ Technologies

3v Powered Super Bright LED Flasher -  I have posted several kinds of LED flashers over the years.   This is yet one more flasher, designed to flash any high power LED of any color.  It hits the LED with a 25ms 250ma pulse once every 2 seconds.   This works out to an average current about 3ma.  It . . . Hobby Circuit designed by David Johnson P.E.-April, 2009

3v Universal LED Flasher -  This low power LED flasher circuit draws about 100ua from any DC power supply ranging from 3 volts to 24 volts.  The 1.0Hz 10ms LED pulsed current is held to a constant 10ma . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

4 Channel CAR Color Organ -  Back in the 1970's these were popular for use in homes and the colored bulbs were typically place in a box with a sheet of "rippled/bubbled" Plastic in front to break up the light patterns.  Some units gave very impressive light patterns.   __ Designed by G.L. Chemelec

4 Channel HOME Color Organ -  FOUR Channels.  All Channels are Active Band Pass Filters.   __ Designed by G.L. Chemelec

4 channel infrared remote relays -  4 Channel Infrared   (IR) Remote is a simple kit using the famous HT12A and HT12D encoder / decoder chips from Holtek __ Designed by Rajkumar Sharma

4 channel RF remote control -  Why design a project from the start when there are many modules available on the web that can get a project finished in half the time.   __ Contact: Collin Mitchell

4 Channel, 12 Volt Color Organ for a car -  Back in the 1970's these were popular for use in homes and the colored bulbs were typically place in a box with a sheet of "rippled/bubbled" Plastic in front to break up the light patterns.  Some units gave very impressive light patterns.   __ Designed by G.L. Chemelec

40 LED Bicycle Light 555 Timer 6 Volt -  The 555 circuit below is a flashing bicycle light powered with four C, D or AA cells   (6 volts).  Two sets of 20 LEDs will alternately flash at approximately 4.7 cycles per second using RC values shown   (4.7K for R1, 150K for R2 and a 1uF capacitor).  Time intervals for the two lamps are about 107 milliseconds   (T1, upper LEDs) and 104 milliseconds   (T2 lower LEDs) __ Designed by Bill Bowden

40Khz LED Test Signal Generator -  This 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses.  The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals. . . Circuit by Dave Johnson P.E.-February, 2002

40khz TV-VCR Light Source Repeater -  This circuit is designed to be placed directly in front of a standard TV or VCR remote.  The exiting light pulses produced by the circuit match the pulses from the remote but are about 10 times more powerful.  Using the device, the remote can operate a TV or VCR over three times the normal distance. . . Circuit by Dave Johnson P.E.-June, 2000

42V 2.5A Synchronous Step-Down Regulator with 2.5μA Quiescent Current -  11/26/13  EDN-Design Notes   Measure inductance & capacitance over a wide range.  The LT8610 and LT8611 are 42V, 2.5A synchronous step-down regulators that meet the stringent high input voltage and low output voltage requirements of automotive, industrial, and communications applications.  To minimize external components and solution size, the top and bottom power switches are integrated in a synchronous regulator topology, including internal compensation.  The regulator consumes only 2.5μA quiescent current from the input source even while regulating the output.   __ Circuit Design by Hua  Walker Bai

433MHz Super Remote Control -  Using a PIC12F683 and a few transistors, it is theoretically possible to boost the power to a standard 433 MHz remote transmitter module.    (Note hypothetical image at right). 
This design utilized 10 Pulse Coding for maximum range with minimal power draw.  Very short pulses are generated using a voltage multipier circuit described below.   __ Designed by Luhan Monat-Mesa Arizona

433MHz UHF Remote Switch -  Ideal for remote control of practically anything you like and with a range of more than 200m, this wireless transmitter and receiver pair use pre-built UHF modules that make it easy to construct and use.__ SiliconChip

4A, 12V Overvoltage Output Regulator -  The LT4356 surge stopper protects loads from high voltage transients.  It regulates the output during an overvoltage event, such as load dump in automobiles, by controlling the gate of an external N-channel MOSFET.  The output is limited to a safe value thereby allowing the loads to continue functioning.  The LT4356 also monitors__ Linear Technology/Analog Devices App Note, Apr 26th 2010

4-CH Remote Control -  You can construct your own long range infrared (IR) wireless remote using Motorola's MC145026 emitter and MC145027 detector chips.  With your remote you can control devices up to 20 feet (7 meters) away.  It operates similiarly to a TV remote.  You just point the emitter at the detector, push a transmit button.  The detector then interprets your data signal.  You can use this circuit to remotely turn on/off devices (like a motors, relays, home appliances).   __ Designed by Boondog web site

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Control Circuits:   #'s - A       B - C       D - G        H - L       M - P        Q - S        T - U        V - Z

 


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