• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Get free circuit help 24/7

Circuits for Beginners | Basic Circuits | LED Driver | Hobby Circuits | Transistor Circuits

New-Projects | Privacy Policy | About us | Contact | Disclaimer | Copyright

Home » Timer and Delay Relay » Digital Clock Synchronized Programmable Timer Circuit

Digital Clock Synchronized Programmable Timer Circuit

Last Updated on May 13, 2020 by Swagatam 8 Comments

I have already discussed one programmable timer circuit in this blog earlier, the circuit involves the IC 4060 for generating the basic oscillations which is further used for generating the required time intervals, however this cannot be synchronized with an external clock.

The following circuit was requested by Mr.Amit, here the concept makes use of a clock for acquiring the required base timing oscillations and therefore is able to get synchronized with external clocks or watches.

The above  procedure of using simple oscillator module for acquiring the oscillations may look quite impressive, but it accompanies a serious disadvantage.

Using an External Clock for Synchronizing Time

The above type of timers cannot be synchronized with a clock and therefore are never accurate.

The article explained here utilizes a clock's second's pulses for acquiring the basic triggering oscillations for the different sections of the corresponding circuit stages which are divided into minutes, hours etc.

These outputs are suitably configured with a set reset latch for obtaining the required programmable timer application needs.

As shown in the figure the circuit basically incorporates many 4017 ICs for dividing the source seconds pulses into minutes and hours.

How it Works

Each IC 4017 consists of 10 output ports which become high and low sequentially in response to the inputs applied at its pin #14.

It means if a pulse of one second duration or 1Hz is applied at the input, the Pulse will become of 10 seconds duration at pin #3 of the IC.

The first IC from left is applied with the seconds pulses derived from a regular digital clock.

As explained above, it's pin#3 now generates 10 seconds of time interval, meaning it goes high after every 10 seconds.

This pin#3 is next connected to the input of the second 4017 IC, which again does the same, increases the time interval *10, that is it generates 10*10 = 100 seconds time, however since its pin number 5 is connected with pin#15, this IC generates 60 seconds time duration at its pin#3.

This 60 sec time interval is further applied to the input of the next 4017 IC, which now in the same way transforms this input into a period of 60*10 = 10 minutes.

The above 10 min time interval is again applied to the input of the next 4017 IC producing an output of 10*6 = 60 minutes. that is equal to 1 hour at its pin #3.

The above procedure may be increased to any number of time interval outputs just by adding more and more 4017 ICs in the array.

Now interestingly, the timing generated at the respective IC's pin outs are all in accordance to the main input acquired from the digital clock's seconds pulse, therefore are perfectly co-ordinated with the clock timing.

If you are interested to achieve a programmable feature from the above set up, you just need to appropriately calculate, assess and integrate the relevant pin outs from the corresponding ICs to the SET Resest Latch circuit input trigger terminals,  as explained below:

Using a Set/Reset Latch

The set reset latch circuit shown in the diagram is actually nothing but a simple latching set up, which can be used to activate a relay through one of the inputs (set) and reset it back to deactivate the relay via another input trigger.

The two input triggers are separate and may be individually acquired from the above explained IC 4017 pin outs. How you would like to achieve a particular set of triggering action as per your needs will solely depend how you analyze the above set up and configure the respective pin outs with the set reset latch.

The relay associated with the set reset latch will eventually be responsible for activating and deactivating a particular load discretely as per the assigned timing inputs from the 4017 ICs.

You'll also like:

  • 1.  Delay based Motor Speed Controller Circuit – Timer Controlled
  • 2.  Bathroom Lamp Timer Circuit with Buzzer
  • 3.  Timer Circuits with Auto Pause and Memory During Power Failures
  • 4.  Adjustable Timer Circuit Using IC 555
  • 5.  IC 4060 Latching Problem [Solved]
  • 6.  Simple Adjustable Industrial Timer Circuit

About Swagatam

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.
If you have any circuit related query, you may interact through comments, I'll be most happy to help!

Subscribe2


 

Reader Interactions

Comments

    Your Comments are too Valuable! But please see that they are related to the above article, and are not off-topic! Cancel reply

    Your email address will not be published. Required fields are marked *

  1. jason bobis says

    Sir.. I don't really fully understand this circuit but can I use it as a 30 second timer?and if yes How?

    Reply
    • Swagatam says

      jason, for 30 seconds delay you can try the following circuit, the above is far too complicated:

      https://www.homemade-circuits.com/2013/10/simple-adjustable-industrial-timer.html

      Reply
  2. Norman Kelley says

    Hi Swagatam,
    I am questioning the above circuit. Don’t we have to take the output from pin 11 of the first 4017 to pin 3 of the second 4017 and take the output from pin 1 (with pin 5 connected to pin 15) of the second 4017 to get one minute with a 1 Hz input to the first 4017. I am trying to make a hourly alarm similar to a Koo Koo clock. I am using a CD4060 with a 32.768K Hz oscillator to produce a I Hz clock signal. I then take the I HZ single to pin 3 of the first CD4017. I then take the output at pin 11 of that CD4017 and feed it into pin 3 of the second CD4017 and take the output from pin 1 of that CD4017 to get one minute. I repeat the previous to get 1 hour. Maybe, I am overthinking this, but it seems to me that the timing will be off because when pin 11 energizes it triggers the pin 3 of the next CD4017 which gives a shorter time because pin 11 did not use up its complete time. If pin 3 were triggered by a falling edge, then it would be more correct. The 6 stage is correct as the reset is set from pin 5 to pin 15 which allows pin 1 (the sixth division) to complete. Are my assumptions correct? Do you have a solution around this problem? Thanks for your help!

    Reply
    • Swagatam says

      Hi Norman, Are you referring to pin 11 to pin 14? because connecting pin 11 with pin 3 will yield nothing.

      Reply
  3. Norman Kelley says

    Yes, I meant pin 11 of the first cd4017 connected to pin 14 of the second cd4017 for the divide by 10 and pin 1 of the second cd4017 connected to pin 14 of the third cd4017 for the divide by 6. Of course pin 8, pin13 and pin 15 on the first cd4017 grounded and pin 5 connected to pin 15 and pin 8, pin 13 grounded on the second cd4017. Sorry for the mind block!

    Reply
    • Swagatam says

      As you pointed out, using pin11 to trigger the next IC may create a malfunctioning in the timing outputs, therefore the above set up looks OK to me, unless of course there’s no triggering of pin14 at power switching ON, after pin15 has been reset. I don’t think that might happen since pin14 requires a subsequent low and high clocks to trigger, so a continuous initial high after reset may not cause any triggering of the ICs.

      Reply
  4. Norman Kelley says

    Thanks Swagatam! I think I am following your reasoning. When the circuit is first powered, all pin #3’s are positive, so output of the fourth CD4017 will sound the alarm (which I will control the length of time sounded with a one shot circuit). After 10 minutes the fourth CD4017 will switch and pin#3 will be low and pin #2 will be high. After 60 minutes the fourth CD4017 pin#3 will be high again. This is exactly what I wanted. You are amazing! Thanks!

    Reply
    • Swagatam says

      Thanks Norman, Glad I could help, wish you all the best!

      Reply

Primary Sidebar

Categories

  • 3-Phase Power (15)
  • 324 IC Circuits (19)
  • 4017 IC Circuits (53)
  • 4060 IC Circuits (25)
  • 555 IC Circuits (98)
  • 741 IC Circuits (19)
  • Amplifiers (58)
  • Arduino Engineering Projects (82)
  • Audio Projects (94)
  • Battery Chargers (82)
  • Car and Motorcycle (94)
  • Datasheets (46)
  • Decorative Lighting (Diwali, Christmas) (33)
  • DIY LED Projects (89)
  • Electronic Components (97)
  • Electronic Devices and Circuit Theory (35)
  • Electronics Tutorial (109)
  • Fish Aquarium (5)
  • Free Energy (35)
  • Fun Projects (11)
  • GSM Projects (9)
  • Health Related (18)
  • Heater Controllers (28)
  • Home Electrical Circuits (101)
  • How to Articles (20)
  • Incubator Related (6)
  • Industrial Electronics (28)
  • Infrared (IR) (40)
  • Inverter Circuits (98)
  • Laser Projects (12)
  • LM317/LM338 (21)
  • LM3915 IC (25)
  • Meters and Testers (63)
  • Mini Projects (171)
  • Motor Controller (66)
  • MPPT (7)
  • Oscillator Circuits (24)
  • PIR (Passive Infrared) (8)
  • Power Electronics (33)
  • Power Supply Circuits (74)
  • Radio Circuits (9)
  • Remote Control (47)
  • Security and Alarm (61)
  • Sensors and Detectors (116)
  • SG3525 IC (5)
  • Simple Circuits (74)
  • SMPS (29)
  • Solar Controllers (61)
  • Timer and Delay Relay (54)
  • TL494 IC (5)
  • Transformerless Power Supply (8)
  • Transmitter Circuits (40)
  • Ultrasonic Projects (14)
  • Water Level Controller (45)

Circuit Calculators

  • AWG to Millimeter Converter
  • Battery Back up Time Calculator
  • Capacitance Reactance Calculator
  • IC 555 Astable Calculator
  • IC 555 Monostable Calculator
  • Inductance Calculator
  • LC Resonance Calculator
  • LM317, LM338, LM396 Calculator
  • Ohm’s Law Calculator
  • Phase Angle Phase Shift Calculator
  • Power Factor (PF) Calculator
  • Reactance Calculator
  • Small Signal Transistor(BJT) and Diode Quick Datasheet
  • Transistor Astable Calculator
  • Transistor base Resistor Calculator
  • Voltage Divider Calculator
  • Wire Current Calculator
  • Zener Diode Calculator

Facebook
Twitter
YouTube
Instagram
My Facebook-Page
Quora

© 2022 · Swagatam Innovations

We use cookies on our website to give you the best experience.
Cookie settingsAccept All
Privacy & Cookies Policy

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Please visit the Privacy Policy Page for more info.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Non-necessary
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
SAVE & ACCEPT