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Timers and Counters Circuits

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

 

Last Updated: November 30, 2017 10:28 AM

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 can’t 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 can’t 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:

Precision 1hz Clock -  This precision 1Hz clock uses just two ICs  and one junction field-effect transistor (JFET) in conjunction with a commonly available crystal and a handful of other passive components.  The Pierce-type crystal oscillator...__ Electronics Projects for You

Precision 1hz Clock Generator using Chip- On-Board -  This is a circuit that generates 1 Hz clock pulse using COB and a op-amp.  __ Electronics Projects for You

Precision Metronome & Pitch generator -  Precision Frequency generator 1 to 999 Hz; Precision Metronome 1 to 999 beats per minute __ Contact Flavio Dellepiane, fladello @ tin.it

Prescaler with Counter -  Digital frequency counter is being used for wide range of applications.  Digital frequency counter extensively uses digital circuits and hence fairly good knowledge of digital circuits and of digital integrated circuits is required to understand the operation of the frequency counter.  However a person who is not familiar with any electronics circuits and experiments has in written this article.  __ 

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

Programmable Clock Oscillator -  PIC -Tock is a video clock using a PIC 16C61.  in the tradition of Marv Newland's "BambI Meets Godzilla", there is far too much ROM space spent on credits, which are smooth-scrolled horizontally on the bottom of the screen.   __ Designed by Eric Smith

Programmable digital timer switch using a PIC Microcontroller -  Digital timer switches are used to control the operation of electrical devices based on a programmed schedule.  This project describes a programmable digital timer based on a PIC 16F628A microcontroller from Microchip that can be__ 

Programmable Divider Restores SVGA Pixel Clock -  03/28/96 EDN Design Ideas:  if you've tried to design a video-overlay board that works with super-video-graphics-adapter (SVGA) graphics through a feature connector, you've probably noticed that the frequency of the supplied clock signal is not always equal to the pixel-clock frequency.  in high-color modes (32, 000, 64, 000, and 16 million colors) , the clock usually runs at 2 or 3x the pixel frequency.  You can restore the pixel clock by using a simple programmable divider, as opposed to the more complex PLL circuit used in many video-overlay boards.  Figure 1 shows the divider circuit __ Circuit Design by Piotr Mazur, Wikom, Warsaw, Poland

Programmable Industrial On-Off Timer with RF Remote -  in most of the modern manufacturing and processing industries, there is complete industrial automation through sophisticated hardware and software like programmable logic controller (PLC) , distributed control system (DCS) , and supervisory control...__ Electronics Projects for You

Programmable Interval Timer for Live Shows -  in live competitions and shows, each item has a predetermined fixed minimum time, maximum time and grace time.  The item being presented should complete between minimum and maximum time.  Sometimes, grace...__ Electronics Projects for You

Programmable Timer for Appliances -  This programmable timer is useful for domestic, commercial as well as industrial applications.  it automatically turns the appliance on/off after a preset time.  The time period can be varied from 8...__ Electronics Projects for You

Projection Clock  -  i'm pretty nearsighted and also an intermittent sleeper, and it has always frustrated me to contort myself far enough to read my clock radio display without my glasses on.   __ Designed by Markus Wandel

Prop Clock Project -  A propeller clock is a fast rotating array of 7 high bright leds.  After triggering the hall sensor it builds a virtual picture.  The software is measuring the time of the rotations to justify the width.  The power for the circuit board and the LEDs is inductive transferred by one of the video head coils.  A infra red LED transfers the DCF signal to the pcb __ Designed by Lucifer Ursum

Propeller Message Display with Temperature Indicator -  Here we describe a microcontroller-based propeller display that displays any message sent to it via hyper-terminal of a personal computer.  Moreover, a temperature sensing IC (TMP125) is mounted onto the propeller...__ Electronics Projects for You

Propellor clock PIC16F84 -  A motor spins the "propeller", and a small microprocessor keeps track of time and changes the pattern on seven LEDs with exact timing to simulate a 7 by 30 array of LEDs.  it is an illusion, but it works nicely.   __ Designed by Boblick

Provide 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

Provide Watchdog for Microcontrollers -  12/26/02  EDN Design Ideas:  The watchdog circuit in Figure 1 uses a single NAND Schmitt-trigger IC .  The circuit iscost-effective than dedicated, commercially available watchdog IC s.  The circuit generates an active-high reset signal upon power-up and remains i __ Circuit Design by VM Holla, Bangalore, India

Provides Linear Resistance-To-Time Conversion -  08/07/03  EDN Design Ideas:  Resistance-based transducers, such as strain gauges and piezoresistive devices, find common use in the measurement of several physical parameters.  For applications in which digital processors or microcontrollers serve for data acqui __ Circuit Design by S Kaliyugavaradan and D Arul Raj, Anna University, Chennai, India

Provides 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

PTT Delay Circuit -  The delay circuit is inserted between the controller and transmitter to provide a set-able time delay keeping the transmitter keyed when using "zero hang time" and linking to another machine. To use this circuit, the controller's repeater ptt must be configured "high true" (dip switch 2 on). __ Designed by Kevin Custer  W3KKC

Pulse Counter using AT89c4051 -  Pulse counters are widely used in our day-to-day life.  Almost all museums and theaters have a visitor counter installed at entry exit to measure the visitor traffic.  in industries, counting is...__ Electronics Projects for You

Pulse generator -  Pulse Generator kit will generate a frequency in KHz which can form a good test gear project.  This kit is based on the classic LM555 timer IC . __ Contact  Rajkumar Sharma

Pulse generator -  A 555 pulse generator circuit with a difference, the initial pulse is tailored by additional circuitry to match the duration of subsequent pulses.
 __ Designed by Miroslav Adzic - Serbia & Montenegro

Pulse Generator Has 0ns to 10ns Width, 520ps Transitions -  it is sometimes desirable to produce extremely short width pulses in response to an input trigger.  Such a predictable, programmable short time interval generator has broad use in fast pulse circuitry, particularly in sampling applications.  This circuit, built around a quad high speed comparator and a fast gate, has a settable __ Linear Technology/Analog Devices App Note, Mar 25th 2010

Pulse Staircase Ramp Generator -  This design highlights the use of the LTC6993-2 and LT1490 to generate a pulse staircase ramp that is re-triggerable.  The pulse staircase ramp output is generated by the LT1490 dual op amp converts pulse frequency-to-voltage and generates a staircase output.  The LTC6993-2 is then configured to reset the staircase.  The LTC6993-2__ Linear Technology/Analog Devices App Note, Oct 6th 2010

Pulse Timer -  IC 1 is wired as a monostablee multivibrator.   input pulses are applied to the base of transistor Q1.   This causes Q1 to conduct, taking pin 2 of IC 1 'low'. __ Designed by Paul Hancock

Pulse Width Modulator, LM324 -  Schematic only, no circuits description.   __ Designed by Tony van Roon  VA3AVR

Pure Sine-Wave Wien Oscillator -  Schematic only __ Designed by va3iul

Push Button Switch Debouncer -  This circuit will remove the transient spikes and contact bounces from a non-latching push button switch.   __ Designed by Andy Collison

Pushbutton Activates Service Request Beeper -  A single press of a pushbutton switch turns on a beeper for one second but can’t be activated again for 60 seconds.. . . Circuit by David A. Johnson P.E.-September, 2005

PWM Controller -  This controller will deliver up to 30 amps and control the motor from 5% to 95%.  __ 555-Timer

PWM DC Motor Speed Control -  This is a circuit for controlling the speed of small DC motors, it works nicely as a speed controller for an HO or N gauge model railroad __ Designed by G. Forrest Cook

PWM DC Power Controller -  This DC power supply controller is controlled by pulse width modulation PWM, generated by the circuit around timer IC 2 7555 according to the formula: Duty cycle = ((R1 + (VR1/2) / (R1+R2+VR1)) x 100% Diode D1 is used to bypass resistor R2 and half the effective resistance of the “lower” section of VR1, allowing the __ Designed by Popescu Marian

PWM fan controller in an EMI-susceptible -  02/16/06  EDN Design Ideas:  Control it with either an external negative-temperature-coefficient thermistor or a PIC  microcontroller and its SMBus serial-data bus __ Circuit Design by Dimitri Danyuk, Niles Audio Corp

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

PWM Motor Speed Controller/DC Light Dimmer -  This circuit will work as a DC lamp dimmer, small motor controller, and even as a small heater controller.  it would make a great speed control for a solar powered electric train.  The circuit has been tried with a 5 Amp electric motor using and iRFZ34N FET and worked ok, D1 may need to be replaced with a faster and higher current diode with some motors.  The circuit should work in applications such as a bicycle motor drive system, if you experiment with this, be sure to include an easily accessible emergency power disconnect switch in case the FET shorts out and leaves the circuit full-on. __ Designed by G. Forrest Cook

PWM Motor/Light Controller -  The diagrams are for 12V operation only and there are high side (common ground) and low side (common +12V) versions.  The low side version of the circuit uses an N Channel FET, the high side version of the circuit uses a P Channel FET.  N Channel devices tend to handle more current than P Channel devices, they are also less expensive.  The high side version of the circuit is useful when one side of the load has to be grounded __ Designed by G. Forrest Cook

PWM Timer with  555 -  Schematic only, no circuits description.   __ Designed by Tony van Roon  VA3AVR

PWM using 555 -  A simple oscilator with PWM that can be used to control speed of motors or light intensity. (4/29/2006)  __ Designed by Jose Pino

PWM Watchdog Ensures Upper Bound -  11/07/96 EDN Design Ideas:  With PWM control of power factor, you need a continuous check on excess pulse width and dead periods to protect a variety of systems that may not incorporate such protection.  You also need regular pulsed power to ensure good averaged, reconstructed __ Circuit Design by Shyam Tiwari, IGCAR, Kalpakkam, India

PWM with 555 -  Some useful circuits using the LM555 IC .  Scroll to find the PWM with 555 circuit __ Designed by Jose Pino

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


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