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Control Circuits

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

Last Updated: October 18, 2017 05:04 AM

Circuits Designed by Dave Johnson, P.E.

Battery Free LED FlasherLED flashers have been used for a wide variety of applications.  Some flasher units have been used in food and hardware stores, to draw attention to sale items and are often attached to boxes which dispense product discount coupons. . . Circuit by Dave Johnson P.E.-December, 2010

Battery-Powered Freezer AlarmA typical freezer can contain hundreds of dollars with of food.  If the device becomes unplugged or if the door is left open too long, the food inside can quickly become spoiled.  The hobby circuit below is a battery powered alarm system, which is attached . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Battery-Powered LED Flashing Advertising #2This circuit is similar to flashing LED advertising badge #1.    It uses a CD4013 dual D Flip/Flop IC.    The 74HCT74 IC in #81 does not always work.    As in #81, a single lithium battery will provide months of continuous LED flashing. . . . Hobby Circuit designed by Dave Johnson P.E.-March, 2002

Bi-Directional Charge Coupled Powers MOSFET RelayThe circuit uses an inexpensive C-MOS inverter package and a few small capacitors to drive two power MOS transistors from a 12v to 15v supply.  Since the coupling capacitor values used to drive the FETs are small, the leakage current from the power line . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000


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

Back & Forth Flasher -  for16 LEDs.   __ Designed by Tony van Roon  VA3AVR

Back EMF PM Motor Speed Control -  Back-EMF refers to using the voltage generated by a spinning motor   (EMF) to conclude the speed of the motor's rotation.   This can be used in motion control algorithms to modulate the velocity or to compute the angular distance the motor has traveled over __ Contact: Acroname Inc.

Ballast that can Be Dimmed from a Domestic Phase Cut Dimmer. -  A system has now been developed, based aroundIR2156, whereballast is able to operate with minimal flicker over a considerable portion of adjustment range of a dimmer and light output may be controlled over this range from maximum output down to around 10%.  

Bang-bang thermostat is Simple Circuit & efficient -  11/06/97 EDN-Design Ideas Perhaps  simplest and oldest feedback loop is  nonproportional, all-or-nothing, "bang-bang" rmostat.  Fully turning on a heater when  temperature is below setpoint and off when it's above setpoint is a straightforward example of a servomechanism.  Yet, elementary and crude as servomechanisms are, examples surround __ Circuit Design by W Stephen Woodward, University of North Carolina--Chapel Hill

Bar-mode LED-cluster sequencer -  Bar-mode LED-cluster sequencer.  Can drive up to 16 clusters.   __ Contact: Flavio Dellepiane, fladello @ tin.it

Bar-mode Lights Sequencer -  Can drive up to 15 LEDs or LED-clusters; Selectable Bar-length __ Contact: Flavio Dellepiane, fladello @ tin.it

Basic FlashLamp Illuminationry for Cellular Telephones/Cameras -  DN345 Design Notes__ Linear Technology/Analog Devices

Basic LED flasher using NE555 timer IC -  This circuit has a lot going for it.  For one thing, it only consists of two transistors, two capacitors and four resistors.  That also means it consumes very little power.  You can control the flash rate by changing the size of the 100k resistors   (100k makes for a pretty slow rate).  You can also control the duty cycle by using resistors of different values on the two sides __ Designed by Colin Pringle

Basic LM3909 LED Flasher -  LED flasher with the LM3909 IC and runs from1.5-Volt battery.   __ Designed by Tony van Roon  VA3AVR

Basic optimizes PhotoTransistor Bandwidth -  04/09/98 EDN-Design Ideas -   (File contains multiple circuits.  Scroll to find this one)  A simple circuit can improve the dynamic performance of a phototransistor for use in low- to medium-speed applications as fast as 100 kbps, such as optical isolation of an RS-232C serial line  (Figure 1).  In low-cost applicationscontains many circuits, scroll to this one __ Circuit Design by David Magliocco, CDPI, Scientrier, France

Basic Stamp I & PC Relay Controller -  This project shows you how to build a relay controller using the Basic Stamp I interfaced to the PC serial port.    The Visual Basic 5 software developed for the interface lets you interact with the Basic Stamp to turn ON/OFF up to   (2) relays attached to the Basic Stamp I/O pins.    As shown below in the screen capture of PC-Relay, it's easy to select the desired com port using the drop-down menu __ Designed by Reynold's Elec

Basic Stepping Motor Controls -  This section of the stepper tutorial deals with the basic final stage drive circuitry for stepping motors.  This circuitry is centered on a single issue, switching the current in each motor winding on and off, and controlling its direction.  The circuitry discussed in this section

Basic Tone Control -  This is the basic design diagram of tone control circuit for home audio system.  The circuit can be modified refer to your needs. 

Bathroom Deoderizer Control -  This is the type that has a little DC motor fan positioned above a small container containing a deoderant liquid or jelly, and runs off a D cell.  The photocell turns off the fan when it gets dark.  The LED flashes if the battery is good.   __ Designed by Radio LocMan

Battery Free LED Flasher -  LED flashers have been used for a wide variety of applications.  Some flasher units have been used in food and hardware stores, to draw attention to sale items and are often attached to boxes which dispense product discount coupons. . . Circuit by Dave Johnson P.E.-December, 2010

Battery Low Voltage Beeper -  This circuit provides an audible and visual low voltage warning for 12V battery powered devices.  Idle current: 6ma Low Voltage Warning current: 15ma.   __ Designed by G. Forrest Cook

Battery Powered Night Lamp -  Ultra-Low current drawing1.5 Volt battery supply __ Contact: Flavio Dellepiane, fladello @ tin.it

Battery Saver -  Worth  effort! The Battery Saver is designed to prolong the battery life in small toys and devices by disconnecting the load after a preset period.  The two versions shown switch up to one amp and give about one minute of operation before shutting off __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Battery-operated remote-temperature sensor drives 4- to 20-mA current loop -  12/17/04 EDN-Design Ideas You can remotely measure temperature using a 4- to 20-mA current loop as long as 4000 feet and a battery-powered, white-light LED driver.  You usually configure this equipment to provide a programmable, constant current to an LED from a battery source.  The TPS62300 series of ICs, for example, converts a battery voltage of 2 __ Circuit Design by Scot Lester, Texas Instruments, Dallas, TX

Battery-Powered Freezer Alarm -  A typical freezer can contain hundreds of dollars with of food.  If the device becomes unplugged or if the door is left open too long, the food inside can quickly become spoiled.  The hobby circuit below is a battery powered alarm system, which is attached . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Battery-Powered LED Flashing Advertising #2 -  This circuit is similar to flashing LED advertising badge #1.    It uses a CD4013 dual D Flip/Flop IC.    The 74HCT74 IC in #81 does not always work.    As in #81, a single lithium battery will provide months of continuous LED flashing. . . . Hobby Circuit designed by Dave Johnson P.E.-March, 2002

BattMan II: a Computer Controlled Battery Manager -  BattMan II is a computer controlled battery manager, intended for typical rechargeable batteries used by R/C and electronics hobbyists, as well as various consumer product batteries.   __ Designed by Stefan Vorketter

Baxandall Tone Control -  This is the most common of all modern tone control circuits, and was named after PJ Baxandall who came up with the idea many years ago.  The original design was article was entitled "Negative Feedback Tone ControlIndependent Variation of Bass and Treble Without Switches",  __ Designed by Rod Elliott  ESP

BEAM Stepper -  74AC240-based circuit to drive small bipolar stepper motors   (e.  g.  , ones in floppy drives)  __ Designed by Wilf Rigter

BEAM Stepper drive -  The 74AC240 stepper driver works by alternately enabling each half of the buffer.  Only one half can be enabled at a time.  Let's assume that the top half of the driver is enabled.  U1A & U1B along with R8, C1, and the input protection resistor R7 form a square wave oscillator.  The outputs of U1A & U1B directly drive one coil of a bipolar stepper motor.   __ Designed by Duane Johnson and Wilf Rigter

Beat Tracking Strobe -  Strobe lights have always been an integral part of dance parties, adding an additional element of excitement to the festivities on hand.  The combination of flashing lights and music-especially those with a definitive strong beat- are a natural complement to one another, where the strobing of light is an extension and links one's aural perception to his visual senses.  The applications of strobe lights are numerous.  In more involved and comprehensive applications the strobe user would like the strobe to help fuse together the music and light.  For our final project we opted to attempt to create such a strobe system appropriate for the more complex application by creating a light strobe system that flashes a light source directly in sync with the music in real time __ Designed by Chris Chan and Kenneth Liu

Bedside Lamp Timer -  30 minutes operation; Blinking LED signals 6 last minutes before turn-off __ Contact: Flavio Dellepiane, fladello @ tin.it

Beetle Mk III -  This project is based on our most stable FM transmitter.  It has a number of features, with a volume control to adjust the input level and a small, neat box to make it easier to attach to a guitar.  The volume control is positioned at the end and when turned up fully, the transmitter provides fuzz   (distortion).    __ Contact: Collin Mitchell

Bell-Cum-Light Controller -  This bell-cum-light controller circuit is equipped with four switches labelled S1 through S4.  While S4 is the mains ‘on’/‘off’ toggle switch for powering the timer circuit for lighting up a bulb...__ Electronics Projects for You

Bells ring Generator -  Three circuit options; Can be synchronized to Christmas tree flashing lights __ Contact: Flavio Dellepiane, fladello @ tin.it

Better Volume (and Balance) controls -  A volume control using a linear pot that is much better than most log pots __ Designed by Rod Elliott  ESP

Better Volume Control -  how to create a log pot that is better than the "real" thing __ Designed by Rod Elliott  ESP

Bicycle back Safety Light -  Flashing 13 LED unit, 3V supply; Also suitable for jogger/walkers __ Contact: Flavio Dellepiane, fladello @ tin.it

Bicycle rear flashing LED light -  No circuit description, schematic only__ CdS Electronic

Bi-Directional Charge Coupled Powers MOSFET Relay -  The circuit uses an inexpensive C-MOS inverter package and a few small capacitors to drive two power MOS transistors from a 12v to 15v supply.  Since the coupling capacitor values used to drive the FETs are small, the leakage current from the power line . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000

Bidirectional Motor Speed Controller -  Easy-to-build project can control the speed of 12-24 V DC motors in both forward and reverse directions.__ SiliconChip

Bi-Directional Motor Speed Regulator -  This circuit shows the concept I used in the drill motor control that I submitted earlier.  I cam up with it in 1994 when I built the device.  My algebra and my patience are a bit too rusty at my age now to write an equation that describes the relationship between the BEMF of the motor and Vin.   __ Designed by Andrew R. Morris

Bidirectional Photoelectric SystE - M -  Detects and counts inputs and outputs.  Suited to control Lamps, Household Appliances etc.   __ Contact: Flavio Dellepiane, fladello @ tin.it

Bike Turning Signal -  This circuit can be used to indicate left and right turn on a motor-bike.  Two identical circuits will be needed, one for left and one for right.  __ 555-Timer

Bipolar Stepper Motor Control -  First, we want to explain how such a controller works and what’s involved.  A bipolar motor has two windings, and thus four leads.  Each winding can carry a positive current, a negative current or no current.  This is indicated in Table 1 by a ‘+’, a ‘–‘ or a blank.  A binary counter (IC1) receives

Bipolar Stepper Motor Control -  In this circuit, a potentiometer controls both the speed and direction of a small bipolar stepping motor like those found in many 5 1/4" floppy disk drives.  Note that the bipolar motors are distinguished from "unipolar" types, in that bipolar units have two coils instead of four, and four wires instead of five.  With the potentiometer at the extreme counterclockwise position, the motor runs counterclockwise at the maximum speed.  Rotating the potentiometer toward the center slows the motor, until it stops.  Continuing potentiometer rotation clockwise, the motor starts to run clockwise, increasing in speed to the maximum clockwise position __ Designed by Arthur Harrison

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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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