Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com has links to 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.

HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches
Welcome to DiscoverCircuits.com - online since 2002

See Media Kit for
Advertising Opportunities

Attention Designers:  Please alert us by eMail if we have linked to sites
where your original material has been copied without your permission.
We will change to the LINK to your site.  
Thank you.

 


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 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

Consulting Services include:
Applications Engineering   --    Design & Development
Electronic Circuit Design   --   Custom Test Fixtures

Call 806-368-7747


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

Machine Gun -  This circuit produces a sound very similar to a machine gun:__ 555-Timer

Mains Clock Controller using AT89C2051 -  The Clock Controller V1.1was designed to be an exemplary of using 'C' language to control timer0interrupt, 7-segment LED and keypad scanning.  it provides 1-bit sink currentdriving output, for driving a relay, opto-TRIAC, say.  Many projects requiring7-segment display and keypad interfacing may get the idea from the Clockcircuit and software.   __ Designed by Wichit Sirichote

Mains Interruption Counter with Indicator -  This circuit counts mains supply interruptions (up to 9) and shows the number on a 7-segment display.  it is highly useful for automobile battery chargers.  Based on the number of mains interruptions, the user can extend the charging time for lead-acid batteries.   __ Designed by Electronics Projects for You

Maintain precise timing with PC's speaker logic -  07/11/02 EDN Design Ideas:  Precise timing control is paramount in data acquisition and analysis and especially in digital-signal processing.  The easiest way of maintaining timing control in a PC is to use delay loops.  The disadvantage of this implementation is that the delay loop's elapsed time depends on the system's operating frequency __ Circuit Design by DS Oberoi, CEDTI, and Harinder Dhingra, GCET, Jammu, India

Make a DAC with a microcontroller's PWM timer -  09/05/02 EDN Design Ideas:  Many embedded-microcontroller applications require generation of analog signals.  An integrated or stand-alone DAC fills the role.  However, you can often use PWM signals for generating the required analog signals.  You can use PWM signals to create both dc and ac analog signals.  This design idea shows how to use a PWM timer to simultaneously create a sinusoid, a ramp, and a dc voltage __ Circuit Design by Mike Mitchell, Texas Instruments Inc

Make an Asynchronous Clock for VPX-Based Pcie Systems -  01/19/12  EDN Design Ideas:  Careful crystal selection and an FPGA are key to success.   __ Circuit Design by Vadim Vaynerman, Bottom Line Technologies Inc, Westminster, MD

Measure settling time to 1 ppm -  03/04/10  EDN Technical Article: intense, extensive, and protracted effort yields a measurement circuit with 20-bit resolution.  nstrumentation, function generators, inertial navigation systems, ATE (automatic test equipment) , medical apparatus, and other precision applications now require 18-bit converters.  The resolutions of these converters are so precise that measuring various performance parameters is difficult.  DACs’ dc specifications are relatively easy to verify, but their ac specifications require more sophisticated approaches to produce reliable information.  A DAC’s settling time is the elapsed time from an input code application until the output remains within a specified error band around the final value.   __ Circuit Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Medical timer warns when pills are due -  05/10/01 EDN Design Ideas:  Some people need to take medication at precise, regular intervals.  When you're in a hospital, a medical staff is present to ensure that you take your medication on time.  But when you're taking medication at home, you must frequently look at the clock-a clear annoyance.  When my wife was pregnant, she needed to take medication every two hours from 8 am to 10 pm.  To help her time the two-hour intervals, I built the battery-powered circuit in Figure 1.  The circuit derives its power from a 9V PP3 battery.  All the ICs  are CMOS -based; the low power consumption of the circuit allows one-week autonomy.  When you press the start button, BP1, a two-hour delay commences.   __ Circuit Design by J Terrade

Medicine-Time Reminder -  We are all so busy with our daily lives that we forget to take our medicines on time, which can have several ill effects on our health.  The circuit described here...__ Electronics Projects for You

MEMS oscillator evaluation board for SiT8008/SiT8208/SiT8209 from SiTime -  Evaluated with the SiT8008/SiT8208/SiT8209/SiT3808 __ Designed by Alexander C. Frank, aka Ajarn Changpuak

Metal Detector -  This circuit detects metal and also magnets.  When a magnet is brought close to the 10mH choke, the output frequency changes.  __ 555-Timer

Microcontroller provides timer function -  01/04/01 EDN Design Ideas:  The circuit in Figure 1 is a µC-based programmable timer with two output channels.  The first channel, activated by pressing the red switch, S3, has a red LED at its output.  This channel is active until it reaches its desired time-out point.  The second output channel connects to a green LED __ Circuit Design by Tito Smailagich, ENIC, Belgrade, Yugoslavia

Microcontroller-based 4-digit Counter Modules -  Two simple low cost counter modules.__ SiliconChip

Microcontroller-Based School Timer -  The basic requirements of a realtime programmable timer generally used in schools and colleges for sounding the bell on time are: • Precise time base for time keeping.  • Read/write memory for storing...__ Electronics Projects for You

Micropower 1MHz V/F Converter -  A 0V to 5V input produces a 0MHz to 1MHz output frequency.  __ Linear Technology/Analog Devices App Note, Jun 21, 2011

Miniature Real-Time Controller -  My long history homeuse controller, a Miniature Real-time Controller controls night light, A/C, household appliances with programmable scheduler.  Modified source code and hex file for year 2002 readout.  New source code in c program.   __ Designed by Wichit Sirichote

Model Lighthouse -  This project was designed for a model lighthouse to flash a lamp or LED in a simple sequence: two flashes of 2s with a short gap of 1s, followed by a longer gap of 5s before repeating the sequence.  A 4017 counter is used to produce the flash sequence and this project includes information on how to adapt it to give a different flash sequence __ Designed by John Hewes

Model Railway Level Crossing Lights -  The level crossing warning lights are switched on automatically as a train approaches.  First an amber light shows, then two red lights flash until the train has passed the crossing.   __ Designed by John Hewes

Model Railway Signal -  This signal is controlled automatically by a passing train fitted with a magnet.  it can also be manually set to red or green by pressing the switches.  Trains will automatically stop at the red signal.   __ Designed by John Hewes

Model Railway Time -  Here is a circuit that will convert any clock mechanism into Model Railway Time.  For those who enjoy model railways, the ultimate is to have a fast clock to match the scale of the layout.  This circuit will appear to "make time fly" by turning the seconds__ 555-Timer

Modeller’s Clock -  The special feature of this analogue wall clock is that it uses a standard model servo to tell the time.  The display principle is the same as for an ordinary wall clock, but with two important differences.  A standard model servo is unable to cover a travel of 360°, so we’ll need to adapt the clock face to this situationmust register on this site __ Designed by Published in Elecktor July/Aug, 2010

Modified DDS Functions as Baud-Rate Generator -  07/15/10 EDN Design Ideas:  Direct digital synthesys lets you generate a clock at frequencies needed for a standard serial port.   __ Circuit Design by Vardan Antonyan, Glendale, CA

Momentary Switch with 555 -  Based on NE555 this circuit turns on and off the IC output by a momentary switch.  in other words it works as a mechanical latching relay, but the circuit backs to the start condition when you switch off the power supply.  This feature is often required in automotive devices.  No relay contacts are used, infact I connected the __ Designed by Andrea De Napoli

Monostable 555 -  When the circuit is turned on, the output is LOW and a brief negative pulse on pin 2 will make the output go HiGH for a period of time determined by the value of R and C.  if pin 2 is low for longer than this period, the output will remain HiGH while pin 2 is LOW and immediately go LOW when pin 2 goes HiGH__ 555-Timer

Monostable Mode Operation One Shot Pulse -  Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc

Monostable multivibrator -  The schematic for a monostable multivibrator is shown in figure 3-11.  Like the astable multivibrator, one transistor conducts and the other cuts off when the circuit is energized.  __ Integrated Publishing, Inc.

Monostable Timer -  Use of the ubiquitous 555 timer in monostable mode.   __ Designed by Andy Collison

Morse Beacon -  The Morse beacon can be programmed with a short sentence or phrase, which is then retained in non-volatile memory and subsequently keyed out automatically in a repeating fashion as might be done to advertise a callsign, etc.   __ Contact Karen's Microprocessor Projects

Morse Clock-Look Mum, No Hands! -  if you want to know the time, you've got to learn Morse code.__ SiliconChip

Morse Code Alarm Clock Modification -  (Almost) Trivial application of an AT90S2313 or ATtiny2313 in an alarm clock to change the alarm from "BEEP BEEP BEEP BEEP BEEP BEEP BEEP BEEP" to "WAKE UP" in Morse code.  This was designed in response to a request and is in daily use __ Designed by Dick Cappels

Morse Code Practice Keyer 2 -  The speaker (LS1) can be any 8-ohm type up to 2-watts.  Supply voltage for this circuit is up to 15 volts, but 12V is more desirable if you choose to go with an adapter.  if possible, try to use a mylar or polyester kind of capacitor for C2 __ Designed by Tony van Roon  VA3AVR

Morse Code Practice Oscillator -  The speaker (LS) can be any 8-ohm type up to 2-watts.  C1 and C2 are ceramic capacitors.  C3 is an electrolytic type.  IC 1 is a CMOS MC1455P or equivalent.  The CMOS type consumes a lot less current when used with the 9-volt battery, but if you don't want to spent the money then the LM555, NE555, etc.  are fine too and are pin-for-pin compatible with each other __ Designed by Tony van Roon  VA3AVR

Mosquito Repeller -  This circuit produces a tone above the human audible range and this is supposed to keep the mosquitoes away.  You need a piezo diaphragm that will respond to 15kHz and these are very difficult to find.  __ 555-Timer

Motion Detector Alarm -  This motion detector alarm circuit can detect a moving person from a distance of 1 meter.  it uses a Dual IR Transmitter-Receiver module HOA1405.  When the sensor detects the reflected IR rays, Alarm will sound for 2 minutes.  The circuit can be modified for various applications including AC operated alarm systems.  Motion __ Designed by D Mohankumar

Motion Detector using Ne555 Timer -  This circuit is based on a passive infrared (PiR) sensor, which automatically switches on a device when someone comes close to it.  it can be used for detection of theft or...__ Electronics Projects for You

Motion Sensor for Security Light -  Here is a system based on PiR motion detector module BS1600 (or BS1700) that can be used for security or corridor lighting in power-saving mode.  The 12V DC power supply required...__ Electronics Projects for You

Motor PWM -  The speed of a motor can be adjusted by this circuit, from 5% to 95%.  __ 555-Timer

Motor Speed/Direction Control for Full H-Bridge (Locked Anti-Phase Drive) -  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 LTC6992’s internal master oscillator frequency.  The output frequency is determined__ Linear Technology/Analog Devices App Note, Jun 16th 2010

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

Multifunction LCD Clock with Raspberry Pi -  With just two simple Python files, an inexpensive LCD display and a low-cost digital temperature sensor, you can turn Raspberry PI into a beautiful LCD clock with IP address and temperature...__ Electronics Projects for You

Multifunction Rechargeable Clock -  Building clocks are one of the interesting and easiest projects that can be seen among hobbyists and makers.  Presented here is a multifunction rechargeable clock unit that not only functions as...__ Electronics Projects for You

Multiple Pulse Generator -  I used this circuit to ring my doorbell rapidly three times when a car pulled into my driveway.  R2 and C2 set the output frequency.  Use a diode and resistor to change the duty cycle, if desired.  R1 and C1 set the cycle time which sets the number of pulse __ Designed by Andrew R. Morris

Music Box -  This circuit produces 10 different tones and by selecting suitable values to change the voltage on pin 5, the result can be quite pleasing.  Note: the two unused outputs of the 4017 produce a tone equal to that produced by the 555 when pin 5 has no external control voltage.  __ 555-Timer

Music Box -  This little novelty uses the PIC  PWM output to produce an approximation to decaying sine waves, which sound very much better than fixed amplitude square waves, but its still far from precision function generation! !  An LDR provides a simple way to detect when the lid of the music box is opened.  Alternatively of course, pin 13 (RB7) can be tied low and a microswitch employed on the power rail.   __ Contact Karen's Microprocessor Projects

Got Designs?
Please eMail
if you want me to link to and/or post your original design.  Thanks.

     <<<         >>> 


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

 


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



 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |   
Privacy Policy


Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.


© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.