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Timers and Counters Circuits

Timers & Counters:  #'s - A      B - D      E - L      M - S      T - Z

 

Last Updated: October 24, 2017 02:55 PM

Circuits Designed by Dave Johnson, P.E. :

Motorized Duck Decoy Timer -  I received a nice email from a duck hunter.  He uses some motorized decoys to lure ducks into his line of fire.  However, the battery powered decoys only have an on/off switch so once turned on; the decoy flaps its wings or paddles around continuously.  The hunter wanted a more realistic motion, which would power the motor for say 10 seconds, then stop for another 10 seconds before starting up again.  The simple circuit below should work well for his application . . . Hobby Circuit designed by David Johnson P.E.-September, 2011

On/Off Flip/Flop Circuit with Automatic Timeout -  This circuit is ideal when a device needs to be turned on and off with a single pushbutton switch, but also needs to turn itself off after some period of time.  With the components shown, the output will stay on for only about 20 seconds. . . Circuit by David A. Johnson P.E.-May, 2012

On/Off Latch Circuit with 2 Second Delay -  A Discover Circuits visitor needed a latch circuit which could operate using a power supply voltage ranging from 3v to 24v.  He wanted to use a tiny pushbutton switch to turn on and off power to a load.  However, he wanted a 2 second delay between the switch activation and the state change of the output. . . Circuit by Dave Johnson P.E.-June, 2013

On/off Pushbutton Switch with 30 Minute Timeout -  I received an email from a Discover Circuits visitor.  He wanted to control power to a LED camping light he was building.  He wanted to turn the light on and off with a small pushbutton switch.  He also wanted a timer so the light would not stay on longer than 30 minutes at a time.  It seems that his kids often turned lights on when going to bed and then forgot to turn them off. . . Circuit by David Johnson P.E.-January, 2012

Poor Man's Timer -  Often during testing of certain equipment and components, you would like to keep track of the elapsed time in hours, minutes and seconds.  There are some nice commercial digital timers and counters available for just this sort of application.  However, . . . Hobby Circuit designed by Dave Johnson P.E.-August, 2008

Press & Hold Latching Circuit -  A Discover Circuits visitor needed a latch circuit which could operate using a power supply voltage ranging from 3v to 24v.  He wanted to use a tiny pushbutton switch to turn on and off power to a load.  However, he wanted a 2 second delay between the switch activation and the state change of the output . . . Hobby Circuit designed by David Johnson P.E.-June, 2013

Pushbutton Activates Service Request Beeper -  A single press of a pushbutton switch turns on a beeper for one second but canít be activated again for 60 seconds.. . . Circuit by David A. Johnson P.E.-September, 2005

PWM Motor Controller uses a 555 Timer -  Using a CMOS version of the 555 timer, this circuit can be used to control the speed of a motor by adjusting the duty cycle of the pulses sent to the motor . . . Hobby Circuit designed by David Johnson P.E.-February, 2007

Service Request Beeper -  A single press of a pushbutton switch turns on a beeper for one second but canít be activated again for 60 seconds. . . . Hobby Circuit designed by David A. Johnson P.E.-September, 2005

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747


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

Scalectrix Lap Timer -  Works by using an LDR under the track, times alternate laps in 10ths of a second __ Contact P. Townshend - EduTek Ltd

Scheme provides automatic power-off for batteries -  05/13/04  EDN Design Ideas:  The circuit in Figure 1 provide as a simple and inexpensive way to protect one of the most valuable components in portable applicationsthe battery.  Applications include all portable equipment that requires a limited time of operati __ Circuit Design by Miguel Gimenez, Altair-Equipos Europeos Electronicos, Madrid, Spain

Scheme speeds access to ĶP's real-time clock -  06/05/98 EDN Design Ideas:  (Scroll to find this circuit) The DS5000T (Dallas Semiconductors, www.  dalsemi.  com) is an 8051-compatible processor that integrates nonvolatile memory and a real-time clock.  This module has an impressive set of functional extensio __ Circuit Design by Jerzy Chrzaszcz, Warsaw University of Technology, Warsaw, Poland

Schmitt Trigger -  Can also be called AN iNVERTER or a SCHMiTT iNVERTER.  We have animated the circuit to show how the output goes high or low according to the input level.  The animation shows a wide gap between the input levels.  __ 555-Timer

School/College Quiz Buzzer -  Manual buzzers used for quiz competitions in schools and colleges create a lot of confusion in identifying the first respondent.  Although there are circuits using PCs and discrete IC s, they are...__ Electronics Projects for You

Science of Timekeeping -  Application Note__ Aligent

Scope tube clock 2D vector numbers -  I was lucky to purcase two used but working DG7 tubes and a transformator cheap, one from Mullard and one from Phillips.  Other CRT Cathode Ray Tube types can be used, you can even rip one from an old and maybe dead oscilloscope __ Designed by Thomas Scherrer OZ2CPU

Screamer Siren-Light Controlled -  This circuit will produce an ear-piercing scream, depending on the amount of light being detected by the Light Dependent Resistor.  __ 555-Timer

Self-powered Sine to Square wave Converter -  This circuit is intended to provide good square waves converting a sine wave picked-up from an existing generator. its major feature consists in the fact that no power-source is needed: thus it can be simply connected between a sine wave generator and the device under test. __ Contact IQ Technologies

Sequential Timer -  This timer will provide a sequence of up to ten separate events.  The length of each event is set independently.  And the sequence will run a fixed number of times, or repeat continuosly.  The individual events within the sequence, can be made to repeat and/or overlap.  The accompanying Support Material includes a detailed description of how the CMOS 4017 works.   __ Designed by Ron J.

Serial or Sequential Timing -  09/26/96 EDN Design Ideas:  in this design, you can adjust as many as eight time intervals, and repeated operation is optional.  You can use the timer to control the external load either serially or sequentially, depending on the application.  The basic timer uses a 4060 (IC 4) with a fixed timing capacitor.  The analog switches connect the timing resistors to the circuit.  A five-stage Johnson counter, IC 1, controls the analog switches.   __ Circuit Design by Sanjay R Chendvankar, Tata Institute of Fundamental Research, Bombay, India

Service Request Beeper -  A single press of a pushbutton switch turns on a beeper for one second but canít be activated again for 60 seconds. . . . Hobby Circuit designed by David A. Johnson P.E.-September, 2005

Servo Controller -  This circuit can be used to manually turn a servo clockwise and anti-clockwise.  By pushing the forward or reverse button for a short period of time you can control the rotation of the servo.  __ 555-Timer

Servo Tester -  This circuit can be used to manually turn a servo clockwise and anti-clockwise.  By pushing the forward or reverse button for a short period of time you can control the rotation of the servo.  it will also test a servo.  __ 555-Timer

Shift Register Divides Clock -  01/05/95  EDN Design Ideas:  Check the circuit in Fig 1; it's more subtle than it first appears.  The 74HCT165 parallel-in, serial-out shift register digitally divideas an input clock by 2, 4, 8, or 16, depending on the bit pattern you load into the device.  Table 1 lists bit patterns f __ Circuit Design by C Shankar, ITI Ltd, Bangalore, India

Shot Clock 24 Second Timer -  This is a circuit intended to be used in basketball shot clock __ Designed by Milano de Guzman

Shower Stopper -  The shower stopper is a project suggested by one of the readers of the Technical Library.  His request was for a circuit that would activate a solenoid to shut off the hot water to the shower after a reasonable length of time.  it seems that certain members of his household enjoy long, warm showers.  This circuit is probably sadistic!  The circuit detects when the hot water is turned on in the shower by means of a __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Simple  Low-Cost Visitors Counter -  Here is a simple and inexpensive visitor counter circuit that you can build easily.  Visitor counters available in the market are generally expensive and are based on microcontrollers, which are difficult...__ Electronics Projects for You

Simple  Parking Counter -  This simple circuit can be used to count the number of cars entering a parking lot.  The circuit is built around comparator LM311 (IC 1) , timer 555 (IC 2) , 4-digit counter IC 74C926 (IC 3) , ...__ Electronics Projects for You

Simple Alert Timer -  This timer is a useful device for people who often forget to turn off devices in time.  Suppose you want to boil water in your electric kettle or cook something on...__ Electronics Projects for You

Simple Circuit 6 Digit 40MHz Frequency Counter Module -  Here is a design for a very low cost 6-digit frequency counter module using offshelf components (and not that expensive 74C926!).  The standard circuit will display directly in Hz (1MHz max) , and re is a separate on board divider that will allow you to display directly in KHz (approx 40MHz max).  Becausedisplay reads directly in Hz or KHz re is no __ Designed by David L. Jones

Simple Circuit AF-oscillator / signal generator using paIR on 2N2222 transistors -  Schematic only, no circuit description __ Designed by Guy Roels ON6MU

Simple Circuit Anticipator Improves On Earlier Idea -  EDN Design Ideas:  05/24/2012   A self-biasing thermistor circuit had an overall dominant thermal/electrical time constant as small as 25 msec but had a significantly rounded response following a square (thermal) input pulse of 100 msec; the source was a pulsed blue LED.  A single-op-amp-based ďanticipator-likeĒ circuit generated a more faithful picture of the actual input excitation, and improved on the circuit described in a previous Design ideas (Reference 1).  The lowpass filter in Figure 1, with an RC time constant of approximately 25 msec, models the circuit. __ Circuit Design by Nicholas Lockerbie, Scottish Universities Physics Alliance, Glasgow, Scotland

Simple Circuit Component & Continuity Tester -  This simple project can be used to test components, circuit board tracks, wires and connections.   __ Designed by John Hewes

Simple Circuit Continuity Tester Fits Into Shirt Pocket -  10-Jan-08 EDN Design Ideas:  A pocket-sized continuity tester responds quickly to shorts or opens and is protected against connection to a live circuit __ Circuit Design by Tom Wason, Phoenixville, PA

Simple Circuit counter for frequency measurements in VHF/UHF band -  This simple counter is useful for frequency measurements of various wireless equipments, especially transmitters, receivers and signal generators in VHF/UHF band __  Jan Kolar

Simple Circuit Diode Temperature Sensor with Frequency Output -  The LTC6992 is a silicon oscillator with an easy-to-use analog voltage-controlled pulse width modulation (PWM) capability.  The LTC6992 is part of the TimerBlox family of versatile silicon timing devices.  A single resistor, RSET, programs the LTC6992ís internal master oscillator frequency.  The output frequency is determined__ Linear Technology/Analog Devices App Note, Jun 16th 2010

Simple Circuit Divide by N using '161s -  Here is a simple circuit for obtaining divide-by-N from '161s.  The technique will work for one, two, or more dividers to obtain the desired N value.  One counter handles N values up to 16, two counters divide by N values up to 256, etc __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Simple Circuit Electronic 'Lock' -  There are six (or more) push switches.  To 'unlock' you must press all the correct ones at the same time, but not press any of the cancel switches.  Pressing just one cancel switch will prevent the circuit unlocking.  When the circuit unlocks it actually just turns on an LED for about one second, but it is intended to be adapted to turn on a relay which could be used to switch on another circuit.  Most relays cost about £2 to £3 extra __ Designed by John Hewes

Simple Circuit GPS Stabilised 10 MHz Oscillator -  Timing and oscillator circuit diagrams / circuit schematics __ Designed by James Miller G3RUH

Simple Circuit phototimer controls load -  04/18/02 EDN Design Ideas:  in industrial and home applications, the need sometimes exists for a device that, after activation by some physical effect, such as light, temperature, or sound, switches a load on for a predetermined time.  The load, such as a lamp, motor, solenoid, or heater, usually derives its power from the ac line __ Circuit Design by Abel Raynus, Armatron International, Melrose, MA

Simple Circuit provides timebase calibration -  04/24/97 EDN Design Ideas:  The circuit in Figure 1 provide as an inexpensive and quick way to check the timebase speeds and linearity in vintage oscilloscopes.  Component aging in the oscilloscopes sometimes alters the timebase parameters enough to yield grossly erroneous results.  You can make timing adjustments in the oscilloscope by using the timing waveforms from the circuit in Figure 1 __ Circuit Design by William Whitehead, Lafayette, CO

Simple Circuit Radio Clock for PC's -  The heart of the device is a EM2S receiver module and matching antenna.  The two are matched, so a mixing a 60kHz receiver board suitable for the MSF and WWVB signals with a 77.5kHz antenna and vice versa will not work.  it should be noted that the receiver boards know nothing about the format of time signal itself so a 60kHz pair suitable for receiving the MSF signal will also receive the WWVB signal __ Designed by Jonathan A. Buzzard

Simple Circuit Servo Controller using 555 Timer -  Servo motors have many uses in everything from robotics to puppetry to photography and beyond.  These little motors can position their output shaft to any position on command hold that position.  Most servos have a range of motion to about 210 degrees and thankfully are very easy to control with a simple circuit such as the one presented here.  Using just a 555 timer and a few support components this circuit can control a servo through it's full rotation based on the position of a pot.  This circuit was originally published in the Think Tank column of the October 1995 issue of Popular Electronics. __ Designed by Aaron Cake

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Timers & Counters:  #'s - A      B - D      E - L      M - S      T - Z

 


Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches



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