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Simple Programmable Timer Circuit

Simple Programmable Timer Circuit

A programmable timer is a device which can be used for switching a load ON and OFF after predetermined delays as per the requirements.

The delay timings are adjustable according to the users personal specs. The ON time delay and the OFF time delay are independently settable and this facility becomes the most important feature of a programmable timer circuit.

Using Versatile IC 4060

In this page we will discuss a very simple yet reasonably useful timer circuit diagram whose ON time and OFF time settings are independently adjustable through ordinary pots.

The idea becomes so easily configurable due to the versatile IC 4060 which require minimal number of component for getting the unit running.



Looking at the CIRCUIT DIAGRAM below we can see that two inexpensive IC 4060 have been wired up as two independent timer modes.

However though the timing settings are independent for the two sections, these are coupled with other such that their initialization become very much interconnected.

Basically both the configurations are similar and have been rigged in the standard counting modes of the IC 4060 devices.

How the Circuit Functions

The output of the upper IC is coupled to the reset input of the lower IC via a transistor in such a way that once the upper IC's output goes high, it triggers the lower timer into operation.

The lower IC then starts counting and when its output goes high, it halts the upper ICs counting and resets it to its original state and the process is initiated back from the start.

It simply means that as long as the upper ICs timing does not lapse the lower IC remains idle, however once the upper ICs timing lapses and its output becomes high, it switches the output load as well as the lower ICs operation.

The pot associated with the upper IC can be used for determining after how long the load will be switched ON, while the pot associated with the lower IC is used for determining how long the load remains in the switched ON position or simply after what time it should be switched OFF.

Update:

The LED positions have been changed in the following updated designs, because the earlier LED positions were conflicting with the relay operations, and therefore the positions have been relocated for ensuring foolproof operations.

Circuit Diagram of a Versatile Programmable Timer

PCB Layout

PCB layout for programmable timer circuit

Video showing the proposed 2-stage programmable timer circuit with LEDs

Using a Start Push-Button

The above design could be upgraded with a push-button to facilitate a push button start. This further ensures that the timer shuts off completely in case a power failure occurs while the circuit is operational, which in turn ensures that crucial loads like heater, or geyser are completely turned OFF during such situations.

Calculating RC Timing Components

It can be done through a formula, but the manual way is much simpler and accurate. It can be done as explained below:

  1. Connect any arbitrarily selected resistor above 100K in place of P2/R2 in the upper circuit.
  2. Switch ON and carefully note down after how much time pin#3 of upper IC 4060 becomes HIGH. This will be your "sample delay".
  3. Once this is noted, other desired time delays could be calculated using the following simple cross multiplication:

Sample Delay / Desired Delay = Selected Resistor / Unknown Resistor

Customizing the Above Concept

This circuit of a flexible programmable timer circuit explained in this article was designed by me in response to a request by Mr.Amit. Let's know more about the request and the circuit details.

Technical Specifications

"I need a circuit for my auquarium where it should do the following

it should switch off the lights at 10:00 pm and start at 7:00 am daily + switch off the light at 12:00 pm daily and switch up at 6:00 pm back.

this will help to make my fishes live longer. 🙂

Thanks in advance.

Amit desai"

The Design

So here's the circuit that I came up with. As the name suggest, the timer is pretty flexible and may be adjusted to produce any desired time periods, according to the above requested format.

The circuit consists of four identical stages, made up of the IC 4060 timer configuration. Te timer sequence begins from the IC at the top left corner.

When power is switched ON this IC starts counting. Depending upon the setting of its pot, the IC triggers after a certain period og time interval.

This switches ON the relay and the driver transistor BC547 which consequently switches OFF the connected lamp. The stage gets latched with the help of the diode connected across its pin 3 and pin 11.
The above triggering  also switches another BC547 transistor which connects the reset pin of the next IC 4060 to ground which initiates this stage also.

After a predetermined time, this IC also triggers its output at pin3 and gets latched by the corresponding diode, however this actionsends a feedback signal to the relay driver transistor, instantly switching it off and restoring power back to the lamp so that it lights up again.

Just as the above actions, the sequence further proceeds and switches ON the third IC 4060 in the line which counts the set time interval and pulls the relay back to OFF position via the diode connected to the collector of its bc547 transistor, such that the lamp again gets switched OFF.

As soon as the above triggering happens the last section at the bottom right corner switches into action and counts as per the setting of the respective pot, until the ICs output becomes high, this high reset the the first IC and switches ON the lamp once again so that the process may be restart the cycle all over again.

The pots may be increased to 3m3 for generating higher time interval periods, so is true with the respective capacitors.

Circuit Diagram

How to Adjust and Set Up

The timer may be adjusted as per the sent request, in the following manner:

If we consider the first timing sequence to begin at 7am and end at 12pm, means the upper left timer's P1 needs to be adjusted such that it activates the relay and switches off the relay after exactly 5 hours.

For keeping the lamp switched OFF in the above position and switch it ON back at 6 pm we now adjust P1 of the upper right timer section such that its output triggers after another 5 hours. This switches ON the lamp again.

The above situation needs to be kept intact until night 10pm, which is about 4 hours of period, therefore we adjust the lower right timer's P1 to get it triggered after 4 hours of time interval.

Finally, for initiating the above procedure back again the next morning at 7am, P1 of the last timer at the lower right is adjusted such that it resets the first timer after 9 hours..... and the cycle repeats.

For making the circuit work according to the above specified timing pattern, after adjusting the respective hours, the unit should be powered or switched ON exactly at 7 clock in the morning....rest will automatically follow.

SHARING IS CARING!


About the Author

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!



316 thoughts on “Simple Programmable Timer Circuit”


  1. Howdy, Friend! Interested to Learn Circuit Designing? Let's Start Discussing below!
  2. Hello sir

    I’m required to create a logic circuit project that is programable meaning it must have a code to it
    I decided to create a switch timer for homes but I’m not really sure about the components to use and how to design them in my project
    How can I go about it with designing my project

    • Hello Charmaine, please provide more details regarding the functioning of the project and the type of code you want it to work with?I’ll try to figure it out..

  3. Hello Sir..

    I want make timer delay 90minutes use CD4060 to control LED.
    idea use single push on /off button to turn on/off LED, also LED can turn off automatically after 90 minutes.
    1. When push button… LED turn ON, Timer start counting.
    2. When push button once again … LED turn OFF, Timer stop.
    3. When push button once again.. LED turn ON and Timer start counting.
    4. if Timer reach 90minutes, LED turn OFF.
    5. if push button once again LED turn ON and Timer start counting

    Can you teach me which circuit suitable with my idea ?
    I try use Timer CD4060, but I cannot stop Timer without waiting until timer reach desired time.

    • Hello Damanhuri,

      you will have to use an SPDT switch for this, a push button will not be appropriate.

      Connect pin#12 of 4060 with the center terminal of the SPDT, connect one outer terminal of the switch with the positive line, and the other with the negative line.

      That’s all, your application will be fulfilled with this!

      Toggling the switch up/down will accomplish the required operations!

      • Hello Sir..

        Thank You for your advice.
        i try, But I found problem. when select switch SPDT to (+) or (-) … only timer stop or start counting, but output IC no change (same as previous condition).
        – SPDT to (+) –> timer stop, Output Low.
        – SPDT to (-) –> timer start counting, Output still Low. (Output High if timer reach desired time).
        – after Output High,

        I need every select switch SPDT, Output also changing.

        • Hello Damanhuri, The IC 4060 will always begin counting with a zero logic, to invert this you can connect a PNP transistor with the IC output. Connect its base with the IC output through a resistor 10K. Connect its emitter with the positive line, and then the relay can be connected across the collector and ground.

          • Hello.

            Thank You for your help.

            I mean, when Output IC Low, and toggling the switch, Output keep Low.
            I need Output change every time toggling the switch.

            For Example :
            a. ON/OFF mode during timer counting (not yet finish desired time).
            – Push switch –> Output Low –> Push Switch –> Output High –> and so on.

            b. ON/OFF mode with Timer reach desired time.
            – Push switch –> Output Low (timer count) –> Timer finish –> automatic Output High –> Push switch –> Output Low (timer count) –> push switch –> Output High –> push switch –> and so on.

            Sorry for your inconvenience cause.

            • I can implement the a) operation, it will be on the output side of the IC. meaning while the timer is counting the output state can be reversed as required from high to low or low to high, so that when the timer finishes counting it will again revert the selected logic by the user.

              I am sure not about the b) option

            • Thank You for your guidance and your patience sir.

              I study some option :
              1. I use single push on/off button on pin#12 (as reset). and adjust Capacitor on pin#9 to change clock to faster counting. (For example use 2 parallel Cap 100pF and 10uF).
              when push button –> timer counting –> push button –> i remove Cap 10uF to faster timer and then timer become finish –> output High.
              But I don’t know how to use electronic switching circuit to control this Cap.

              2. I add Push ON/OFF latch transistor circuit to cut off Vcc of IC 4060.
              so, when push button –> Vcc ON to IC 4060 –> timer start counting –> push button –> Vcc cut off to IC 4060.
              but problem, when push button –> Vcc ON –> timer start counting –> timer finished –> push button –> Vcc cut off to IC 4060 (suppose Vcc ON).

  4. Sir the switch is ok and working properly,thankyou for your guidance and patience sir,😄😄👍,..my only problem now is how to set my desired time,.do you have a tip sir how to get your desired time needed?,.thankyou verymuvh,.👍👍👍

      • Thanks,…sir it is possible to put a reset switch in lower ic?,.how can i do that sir?,.that when i push the reset switch the lower ic reset and start counting,.and the upper ic stop counting,…

          • I need to add a ic 555 sir?,..but the lower ic is 4060,how can i rest it to stop the upper ic counting and the lower ic start counting..

            • OK, I think I got confused with the other comment sent by Mr. Davis.

              If you have IC 4060 for the lower side you can do in this way:

              connect pin#12 with the BC547 collector though a 10K resistor. Now shorting the 1M at pin#12 will reset the lower IC

            • Sir how can i put a switch that can stop the upper ic automaticaly from counting and make the lower ic start to count,.,.like bypassing the upper ic to switch the lower ic 4060,…for example i want to use the the load in my circuit,.when i press the switch the lower ic will start to count,.by passing the upper ic causing it to stop from counting..

            • Ken, connect a push-to-ON switch across the 1uF connected with pin#12. Pressing this switch momentarily will reset the upper IC

            • When i short the 1M in pin12 of the lower ic, the upper ic is still counting,.. I want a switch the stop the upper ic from counting and start the lower ic from counting,..

          • Can u send me a schematic sir,..the lower ic is 4060 sir,..i need a reset switch sir that can stop the upper ic counting and the lower ic start counting,.thanks

            • Yes sir i made the reset in upper ic…how about in the lower ic sir?,.because i connect the collector of bc547 in the pin12 of the lower ic with 10k,and i short the 1M in pin12 of lower ic to reset the lower ic like you said,..it reset the lower ic sir but it only works if the lower ic start counting sir,..i what a switch sir that even the upper ic is not yet finish counting,when u press the switch the upper ic stop from counting and the lower ic start to count,.pls help sir

            • Ken, This is a 2 stage programmable timer which is designed to work in sequence. They cannot run separately. Otherwise you may have to create two of these without linking them together through the lower BC547

  5. Whats the main use of c106 scr in the circuit sir?,..when you push it on using momentary switch it stay on until the power failure occurs or you remove the supply?

    • it’s for latching power to the circuit with a single push of the button…the latch is restored back to OFF when power is switched OFF

            • try it separately. Connect a LED with 1K across anode and positive line, and cathode to ground. If the led latches ON then the ScR is good otherwise there could be some problem with the SCR or its connections.

  6. Hi SWAGATAM I made the circuit for 555 timer and tested it worked for short delay I wanted but when I connected it to the upper 4060 circuit as u told me . It has failed to trigger the load , testing both circuit separately work but don’t know why it has failed .help.thanks

  7. Hi SWAGATAM, for upper circuit help me how to replace the lower 4060 ic with 555timer circuit for short time count ,the reason I have hcf4060 ic tested and was counting as I tested first stage but when replaced with cd4060 the ic failed to count I bought many from different store failed to work but for hcf4060 worked perfectly for that reason I want lower stage I use 555timer for short delay and upper stage using my hcf4060 for long delay.help me my master thanks

    • Hi Davis, you can probably do it in this way:

      remove the lower BC547, and its base 10K
      configure IC555 in its basic astable mode. Connect its pin#4 with pin#3 of IC 4060
      Connect pin#3 of IC555 with pin#12 of IC 4060 through a 1N4148 diode.
      This should do the job

  8. In reference to washing machine agitator circuit because there is no comment section, can I use 12v relay. Can I use electrolytic capacitor of 10uf/25v polarised because there is difficulty in getting for C2 etc. Thanks

  9. Hai sir…*
    Few doubts sir…
    1.Pls tell the function of 1uf polarised capacitor in between 3 and 16..
    2.when the upper case counting starts.The lower case ic not started counting what’s the reason..
    When the upper case ic reaches the time counting then automatically lower case ic starts count and resetting the whole ic…
    Pls explain it how this happening…

    • Kesav, the 1uF is connected with pin#9, it is the timing capacitor and this capacitor along with the resistors at pin#10 determines the delays or the frequency rates at the outputs of the IC. The capacitor must be non polarized ideally
      the upper and the lower timers are designed to work sequentially or in a cyclic manner, that’s why you see them work one after the other and not together,

  10. Sir ,
    Love to see your respnoce, you are in realtime.
    I thought PCB design is through a software like eagle is easy. I can try but I don’t have PC or laptop :-‘)

    • Thanks Anjali, I love answering questions, and I am online most of the time here. I too do not have any PCB software because my expertise is in the field of designing circuits and not PCBs. I only have Coreldraw which is a great software but not a specialist for PCB designing.
      If you are into some kind of electronic business then you must have a PC with you.

      • No I am not belong to electronic field. Well coral draw is very good software but it cannot produce circuit digram to PCB layout.
        But sir you are the admin of this very good blog you must have something like eagle

        • I am sorry I do not have or use any special software such as Eagle, I totally depend on Coreldraw and do everything with it right from schematics to PCB

  11. Sir this pcb layout have both side. may affect on etching ?? I need separate sir four led is not used in circuit digram ??

    • Hi Anjali, I am sorry I am not good at designing PCBs so it’ll difficult for me to modify the design for you. All the PCBs were designed and acquired from an external source. For the flashing LEDs, you just have to add an LEd from pin#14 of the two ICs to ground. just make sure the LEDs have a 1K series resistor with them.

  12. Kudos for the great projects sir! I am Israel you have really inspired me through your home made circuits blog. i am a student and i would like to build an incubator circuit that checks humidity say at 22, temp at 38 celcius, and automatically forwards and reverses a 12v motor
    thanks my email is musomaji@gmail.com

  13. Sir i want to use this circut to control water heater but it start automaticly with power on i need a programable timing circuit that start count with push button and dont start after power cut.

    • Hi Suleman, in this circuit the relay will not start on power switch ON. he relay will switch ON only after the upper IC has finished counting and the upper IC’s stipulated time has elapsed.

      There may be some fault in your circuit or it could be due to the low capacitor value at pin#12 of the upper IC, I have changed it to 1uF…please use this new value and check again

      • I made this circuit several times again and again but i think there is something wrong in the diagram because both two ic work Properly if i don’t connect the lower ic pin 3 to upper ic pin 12 with 1N4148
        If i connect it damage the ic

        • The circuit is thoroughly tested by me and there’s nothing wrong that I can see in the above drawn diagram

          Pin#3 from the lower IC applies a positive logic to pin#12 of the upper IC so that the whole system can reset back to the original condition, how can there be anything wrong in this process??

          you can try this manually also, just touch the pin#12 of the upper IC to the positive supply with a wire, and the IC will reset back to zero.

          make sure your supply input is not above 12V ideally, because 15V is the maximum recommended level.

          If your IC is getting damaged when pin#12 is touched to (+) supply then your IC is definitely faulty or duplicate in quality.

  14. dear sir i want 3 hour timer circuit when power is on the timer wants tostart counting after 3 hours the output relay comes to activate after that i will reset the circuit after resetting the circuit the counting will repeat the same proces

  15. Sir,
    I would like to refer to a post for which you have replied as follows.

    ************************************************************************
    edwin siy says

    December 3, 2015 at 8:48 am

    Good day Sir,I build this awesome circuit but the problem started when I switch on the red led and relay instantly activated while the green led light up after 5 sec. and goes off after 5 sec. but the red led and relay still energize. The green led goes on/off 5 sec. interval continuously with both red led and relay energized. The only components I change are the ff. P1 to 2m and R2 of the lower circuit to 10k and pin#9 of the lower circuit to 0.1uf ceramic cap,the rest stay as is. I know by the way I explained,you already pictured what went wrong. Thank you
    Reply

    Swagatam says

    December 3, 2015 at 2:42 pm

    Good day Edwin,

    red LED will light up when the circuit is initialized, this is correct, but this should not activate the relay because the BC547 is not supposed to activate when the red LEd is ON…it looks contradicting.

    when green LED lights up, the red LEd should shut off….so again the result is incorrect in your circuit.

    try increasing the setting of the pot and check the response in a slow motion to read the operations correctly….there could not one but more issues in your circuit which will need to be traced and eliminated…
    Reply
    *****************************************************************

    Sir, this is the same problem I came across. I also changed the C1 & C2 to 0.22uF and P1 & P2 to 500K since I needed 10 minutes ON and 20 minutes OFF sequence.

    As mentioned in Mr. Edwin Siy’s post, the relay and the red LED keep on activated all the time while the green light comes on and goes off to the set time interval. Further I notice, once the green LED is ON the brightness of the red LED decreases.
    Sir could you please give me an advice and help me to solve this problem.

    Thank you.

    Regards.

    Fernando

    • Hi Fernanado, please understand yourself and try to figure this out….if the red LED is ON, that means pin#3 has to be at zero logic.

      If pin#3 is at zero logic how can the BC547 conduct? because the BC547 will require at least 1V to switch ON.

      My guess is that your IC is not of good quality and due to which it might be leaking some voltage while the upper IC is in the counting mode….

      you can probably remedy this by adding a diode in series with the emitters of both the BC547 transistors….anode will connect with the emitter, while the cathode to ground…do this and check the response.

      also increase the value of the 0.1uF cap at pin#12 of the upper IC to 0.33uF or 0.47uF so that the IC gets correctly reset when the power is first switched ON.

  16. Hi sir
    Myself Rishabh, sir I made this circuit but the problem is that the green led along with the relay turns on when I disturb the wire connected between voltage source and the circuit or when I shake the circuit board , this is a weird please help me.

    • Hi Rishabh, there could be some kind of loose connection in your circuit, i hope you have made it by soldering and not on a breadboard…please check the solder connections and resolder the joints if possible…

  17. Hi sir the circuit is not working properly only the red led is glowing when the p1 is in lowest value , please help.

    • Rishabh, Please go through all the comments and try to solve the problem by referring to them…I cannot troubleshoot your circuit fault because do not know what mistake you might have made in it…it will need a practical checking….

      Or you can first make two individual 4060 timers separately and check them, if you succeed with them, then you could combine them as per the given figure for the final result…

  18. Hi sir,
    My name is Rishabh and I want to ask you one thing that can i use polar caps in this circuit because unfortunately I have got all polar caps of desired rating.

    • Hi Rishabh,

      yes you can use them for all except the ones which are connected at pin#9 of the ICs….here you can put two polar capacitors in series to make non-polar capacitors as shown below:

      —–+||——||+——

      or

      —–||+——+||——

    • Hi John, the above shown design can be used for your application, the upper IC could be set for achieving 12 hour delay and the lower IC for 60 seconds

  19. First of all I would like toltell you that green led is glowing (very low) at the ssametime when red LED is on.
    I removed the diode. Checked there is no blinking only continuous glowing . Also both the LED is glowing . Within 3 minutes upper ic temperature got too high . Extremely hot.

    Plz help… can you plz share another circuit for this. I want to run the motor (cooler) for 3 minutes and after 3 minutes it should be off for 20 minutes. And so on….

    • this IC can become hot under any of the following 3 conditions:

      1) output short circuited
      2) supply voltage above 16V
      3) IC itself is duplicate and faulty.

      I cannot troubleshoot your circuit because I cannot see it practically.

      I would suggest you to buy another good quality IC, and first build a basic timer circuit as explained in the following article.

      https://homemade-circuits.com/2011/12/how-to-understand-ic-4060-pin-outs.html

      connect LEd across its pin#14 and check whether it blinks or not….confirm this and then you can go ahead with the above programmable design as before

    • If possible I may update another circuit using IC 4017/IC555.

      by the way the above IC4060 circuit has been thoroughly tested by me…

    • I again tried. Both ic are are working well. Both led are indicating according to their time. How ever relay is not triggering.
      I used an old battery for power supply whose voltage is 9 voltage.
      Is 12 v supply is must?
      Can I use a DC power adapter of 12 V output & what should be the current out put.
      Plz suggest.

    • That's great, it means you have almost succeeded with this project.

      your relay is definitely not working because of the inadequate input supply, please replace it with any 12V/1amp AC/DC adapter, and it will instantly start responding

  20. I have done the following things.
    1. In Pot 1 & Pot2 : I used two pin. i.e. center pin & side pin.

    Following connections done individually for both the IC.
    2. 2.2Mega Ohm connected between ic pin no. 11 and centre pin of pot.
    3. 100k resistance between IC pin No. 10 & side pin of pot.
    4. 1uf/230vAC between IC pin no. 9 & center pin of POt .
    3. All other component as per circuit.

    Now what happening is :
    1. Red LED is glowing /on and relay is operated.
    2. Red LED is always in on condition. (Green LEd in not glowing).

    Diagnosis result:
    Upper ic: I connected a led +500 ohm resistance between IC pin no#15 and Vss. LEd not glowing. But when connected between pin no. #7 & Vss then continuously glowin.
    Lower ic: led not glowing (gor pin no.# 15 ot pin no. 7)

    I also tried to put bkth the pot on 0 ohmm. Still red LED is always on. There no any delay at all.

    Plz suggest what to do.

    • It looks like your upper IC is getting latched on power switch ON, but in that case the lower IC should begin counting.

      anyway, first confirm the upper IC working by removing the 1N4148 diode across pin#3 and pin#11…..this will allow the LED at pin#15 or pin#14 to blink.

      once conformed reconnect the 1N4148 into position.

      to prevent the power ON latching….increase the value of the 0.1uF capacitor to 1uF….you can use an electrolytic capacitor for this….connect negative terminal to the pin#12 of the IC and positive terminal to positive line….

      do this and see the response

    • rememeber when red will be off and green will be ON when power is switch ON, red will light up, and green will shut off when the upper IC has finished counting…and this will mean that the lower IC has begun counting.

      as soon as the lower IC finishes its counting it will erst the upper IC which will start counting again…the cycle will continue…

  21. Thank for your reply ….
    I have purchased that…
    So in this circuit we have to connect supply voltage to " NO" pin and load wire ro " common pin". Right ?
    And for "No" pin there is no connection . Plz confirm.

    Thank you.

    • The load,the supply voltage, the relay N/O, and the relay pole points must be all wired in series…the exact positions of the load and the supply are not important…they should come in series that's all….

      for N/C point there's no connection…it's unused.

  22. Hello dear swagatam ji
    I'm a Mechanical Engineer. For this simple programmable timer circuit I am unable to find the name of some component and specifications.
    It is my request to you plz share the complete list of component with their specification.
    I will be very great full to you.
    Thank you

    Vivek

    • Hello Vivek,

      please copy all the parts name as given in the diagram and show it to the part dealer, he will be able to understand and provide you with the right components.

      If possible I'll try to upadte the parts list soon…

    • Hello sir I have purchased all the components. One thing I want to confirm there is not "NC" pin in the relay I have purchased . Is it good. Do I need to connect one load wire to common pin and one power supply wire to "NO" pin.
      Plz have a look at the circuit (PCB) and let me know if there is any correction (if any)

      i66.tinypic.com/15mequr.jpg.
      I have made the circuit one you will approve I will run it and will revert back you.

      I hope it will be all good.

      Thanks

    • hello Vivek, every relay will have N/C and N/O pair of contacts…if your relay does not have it then do not use it. change it with the following type:

      1.bp.blogspot.com/-xpR6CBVr5RY/VB7jiU5puOI/AAAAAAAAIRA/gKnCI1xGHFA/s1600/relay%2Bpinout.png

      sorry It will difficult for me to confirm your schematic…I can only assure you about the above schematic, which is perfectly correct…if you follow everything as given in the my diagram then your circuit will definitely work…unless any of the component is faulty.

  23. Dear swagatam ji
    I want to make a circuit which should be "on" for 3 minutes and then "off" for 30 minutes. And after 30 minutes again "on" for 3 minutes and so on . Until the power supply is off.
    Load is about 100 watt (AC).

    Plz help me sir.

    • Hi Vivek, you can try the same circuit which is explained in the above article and get the required sequential timing cycles

  24. dear sir, actually i have three phase motor with dol starter, i want to automatically on the motor after 10 or 15 minutes when failed power is came back, and after running i want one hour stop and one hour run with adjustable on/off timings not exactly 1 hour for example only i say some times 30 minutes some times 10 minutes like that, actually i want circuit for controlling same starter by on/off buttons using relays.

    • Dear KSR, for sequential ON/OFF timing you will need the above explained 4060 circuit in order to get independent ON/OFF switching for your motor, but for the delay switch ON, you will require the circuit which was suggested in the previous comment by me.

  25. dear sir i want a circuit for making motor on after 10 minutes of failed power came and also this operation also. thank you

  26. Hi
    I need a circuit to control the RO plants. The cyclic timer needs to switch on and off the ro plant for 3 hrs. That is First plant on for 3 hrs while second is off for that period. After 3 hrs the first goes off and second starts. The timer should not reset with power failure but continue counting count And keep the running plant on for the balance period after power comes on. Secondly the time setting should be Digitally visual so that it can be set as required between 3 hrs to 4hrs.
    Thanks. Will wait for ur reply.
    Rgds
    Panwar

  27. Tried several time. Circuit not working.
    Wen i switch on red led turns on and relay also turns on.then nothing happens . Doesnot turning relay off
    Help me please

    • remove both the 1N4148 initially and check again.

      check across all the outputs of the 4060 IC by randomly connecting LEd and 1K across each of the pins and ground, make sure at least one of the pins flashes the LED, if none of the pinout flashes the LeD then definitely your circuit has some problems or the IC faulty.

      first confirm this….

  28. Hi Sir,
    Thank you so much for the great work you are doing. I was wondering if you can design a simple timing circuit that can be set to turn a load at specific time (for example 6am everyday) the goes off after specific time (ex 15 min) without my interference. I will be very grateful if you can do that circuit for me.

    • Hi Zack, for getting accurate results you may have to use digital clock and integrate its alarm output with any simple 4060 timer circuit. the integration can be done at pin#12 of the IC.

  29. Hi Swagatam,

    I want to build a 230V AC electric immersion heater (for heating water in a bucket) whose duration of heating the user should be able to set. We use this to boil our borewell water to make it suitable for drinking (we feel RO is too wasteful). Depending upon the bucket size, we heat the water for around 15-25 minutes. The problem is that we get busy in doing other things and sometimes forget to turn it off after that period, often to find it evaporated below the danger mark on the heater. So we use the alarms on our mobiles to remind us. We just want that the device be smart enough to turn itself off, that's all. Auto-off versions of the product are not available in the local market.

    The user should be able to set the ON duration by pressing up- and down- keys (operating 2 switches) to increase or decrease numbers that show on a dual 7-segment display (for showing 1-99). The numbers that show in the 7-segment display is the time in minutes the heater should stay on for and then switch itself off.

    Can you help me with this? Your blog is fascinating as it addresses common needs felt by many people who want to innovate by making their own products. This is mine. Hope you can help.

    • Thank you Ranjit, yes it is possible, and I would recommend to go for a simple 10 LED stage heater controller circuit instead of a digital readout, because here the cut-off might not require an extremely accurate monitoring of the temperature.

      a seven segment readout is also possible but will unnecessarily make the design expensive and complex.

  30. Dear Sir,
    I have made the above circuit and tested using pin 15 and pin 7 of ic. LED blinks at pin 7 of ic2 but not worked at pin 15 of first ic. Relay also operate at start and both LEDs are glowing when power on the circuit. Please let me know your suggestions. I am waiting for your reply.

    • Dear Narendra, move the pot to different positions to verify the blinking at pin#15….

      pin#7 will be much faster than pin#15 and vice versa.

      both LEDs can never glow together…..when pin#3 is high, green will glow….and when pin#3 is low red will glow.

      both ICs will never oscillate (count) together….when upper IC locks (relay ON) lower IC will begin oscillating….and while the upper IC is oscillating (relay OFF) the lower IC will stay disabled

      there's something not right in your circuit

  31. Hello Sir can any of these circuit be modified for time period such as 15sec to 1min? because as i saw only over 5-10mins

    • Hello BlackOwl, you can appropriately reduce the value of C1 to get any desired lower delays from the above timers.

  32. Hi, can u tell me how to use the above circuit with 220v AC supply by inserting a triac to switch a 50watts fan? And when powering the circuit, the circuit should work as on-off-on-off..

  33. sir,i want use this switch for hydroponics where the motor must start automatically for 5-10 minutes after a interval of 2-3 hours will it work for 24 hours

    • Jagtap, you can try the design which is explained in the above article and optimize the pots accordingly for your requirement.

  34. Dear S.M.
    Hope you have a successful life.
    This is Rajab Ali from Afghanistan
    We need a circuit for controlling an aotoclave for sterilization in hospital the machine works as.
    1 when starts cycle by pushing start button it should turn on three water heaters(30_60 Amps) after reaching 2.2 bar pressure from water steam then the circuit keep running with on and off two heaters to control pressure between 1.8 to 2.2 bar for 20 more minutes. If there would be any possibility to adjust the time is great.
    Many warm regards

  35. sir can i run this circuit like, 1 min on then 10 min off in cycles?
    does it remember the pattern after power failure ?
    realy need help sir. plz reply

    • Hi Rameez, yes that's possible with this circuit, if mains fails the circuit will reset and initiate from the beginning, you can add a small battery to it to add a memory to the circuit…

  36. hello sir,
    I tried the above circuit for one of my projects. But i'm not getting the required output. could you please tell me what will be the time period if i give the potentiometer value as 10K ohms. And also could you please let me know much details about the circuit(like components used , working ,calculation of the time etc.,) if possible.

    • hello sai,

      10k will give delay in seconds, to get higher delay periods, P1 should be at least a 1M pot.

      you can use 4060 formula or simply test the time practically using a stopwatch. if suppose 10k gives 20 seconds then 100k will give 200 seconds so you can calculate in that way…

      please click on the diagram, and copy the parts as its given.

      all resistors are 1/4 watt rated… rest needs no specifications as all are standard parts.

  37. Hi Swagatam,

    I'm sure you're very busy but if you could find time to help me out I'd be very grateful!

    I'm designing a product which will have a DC motor, minimum rpm of 100 and torque of around 30Nm. I need to create a control system which will allow the user to switch it on, off and run it on a timer.

    Any help would be appreciated,

    Thanks, Morgan

    • Hi Morgan,

      You did not specify the exact sequence of the functioning, and whether these are required to be automatic, manual, or semi-automatic, so all these info would be required for the correct figuring out of the design or for providing you with the correct instructions.

    • Thanks for the swift reply, not entirely sure what you mean by the sequence bit, but il give you an overview of the product. It is an archimedes screw type device which draws compost out the compost bin. The user should be able to turn it on and off, and also set it to run for say 20 seconds at a time before it switches itself off. Does this give you enough information?

    • OK, you can try the following circuit :

      https://homemade-circuits.com/2014/11/long-duration-timer-circuit-using.html

      remove the push button and replace it with a jumper link.

      Now the ON/OFF switch which may be positioned for supplying the voltage to the circuit will serve as the manual ON/OFF control of the system, for the user.

      Once switched ON, the relay will almost immediately switch ON the load and the circuit will start counting….depending on the values of the 2M2 resistor and the 1000uF cap the relay will be switched OFF automatically ater the set time, switching OFF the load…..in case the user wants to stop the load in the middle of the count, he may do this anytime by simply switching OFF the ON/OFF switch…..otherwise the circuit will do it automatically after the predetermined time elapses….as set by the resistor at the 2M2 position and/or the capacitor at the 1000uF position.

  38. hi Bro i need a circuit that turns off 4 energy savers after 12 hours
    i turn on my energy savers in night at my farmhouse which is almost 20 KMs from my home and to turn off the lights in the morning i had to go there it costs too much fuel and time waste can you design a switch that turns off all lights after 10-12 hours automaticaly

  39. Dear Mr Majumdar,

    I'm working on a project where I need a relay activated for 2 or 3 minutes once every 24 hours. The circuit needs to be battery operated and low power consumption. Will this circuit on this page work? It is for an art installation. Thank you!!! 🙂

  40. Sir
    I hade problem with my 7"angle grinder running all the time so I need timer switch circuit for machine on for 15min then off for 15min that cycle every time so please help me

  41. Sir,
    Can this circuit be used to switch on aquarium lights everyday for 8 hrs?
    What modifications need to be made..
    I am new to electronics
    Total load is 54 watts

  42. Hi
    Can you please help with
    How to connect three phase water pump as load in the circuit with a required delay of 24 hours

    • You can simply change the shown SPDT relay with a three contact SPTP or single pole triple throw relay and use the three contacts of the relay with the 3 phase AC input and the motor

    • it's a relay that's controlling the load, so obliviously you can use any type of load…
      power limit will depend on the relay contact rating..

  43. Good day Sir,I build this awesome circuit but the problem started when I switch on the red led and relay instantly activated while the green led light up after 5 sec. and goes off after 5 sec. but the red led and relay still energize. The green led goes on/off 5 sec. interval continuously with both red led and relay energized. The only components I change are the ff. P1 to 2m and R2 of the lower circuit to 10k and pin#9 of the lower circuit to 0.1uf ceramic cap,the rest stay as is. I know by the way I explained,you already pictured what went wrong. Thank you

    • Good day Edwin,

      red LED will light up when the circuit is initialized, this is correct, but this should not activate the relay because the BC547 is not supposed to activate when the red LEd is ON…it looks contradicting.

      when green LED lights up, the red LEd should shut off….so again the result is incorrect in your circuit.

      try increasing the setting of the pot and check the response in a slow motion to read the operations correctly….there could not one but more issues in your circuit which will need to be traced and eliminated…

    • Dear Paul,

      For equal ON/OFF timer period you can use a single 4060 time circuit, that is eliminate the lower 4060 section entirely.. but you'll need to switch it ON manually each day for achieving the automatic 15min OFF/ON cycle

  44. Hi swagatam,
    Actullay I m going through a prob.I want to know a option that I can fix on my lift so that I get to know the exact total time of my lift when it is used.as I want to calculate the total units consumed by my lift in 24 hrs with 5 kw motor on it.
    If u can sort it out it will be a great help
    Thanx
    Nitin

  45. Yes, exactly, as long as "T1" is at least within .2 to .5 seconds to allow full engagement of the latch before valve is opened.(shortest "T1" time is preferred) Some adjustability for "T2" (via potentiometer I assume) as you stated is required from about .1 to 1 second.

    Sorry if I'm repeating myself.

    And still plan on posting a sketch for all intensive purposes.

    Good day and good night to you from sunny Ontario, Canada

  46. So glad I found this site, might be my new Favorite. I'm an amateur here who's racked his brain enough already. Hoping you can help me out. What I need is an "on delay/true off delay timer" as detailed here–> https://drive.google.com/open?id=0B8cU3NynJy7kekE4bXIxUFBORXM . The signal going to the delay timer will be from a "pulsepause timer" and I would like to just have the delay timer delay that pulsepause signal before replicating it a half second later to another component. Basically I need it to produce the same signal for the same duration but just delayed a fraction of a second.

    Is there something cheap out there that will do this for under $30 or could you provide me with a schematic.

    Thank you

    • Thanks, I am glad you liked my site.

      In your given specs, the input voltage is the supply voltage, however if the supply voltage is removed then the circuit might not function correctly….the supply voltage cannot be removed, only the trigger can be applied or removed.

      Please clarify this, then we can proceed with the designing.

    • Yes, of course. What I should have said is I plan on using the supply voltage to supply the three things that would need it (pulse/pause input,pulse/pause relay input and the delay timer relay input). I suppose this could all be incorporated on one circuit board but I already have the pulse/pause timer and am just looking to add a second delayed signal. But to add to that I would like the "T2" delay (shown in my previously posted link) to be adjustable from about .1 to 1 second. What I am using it for is a pneumatic ball throwing arm. The pulse/pause timer output will be used to trigger a latch to hold/lock the arm and also to trigger the start of the delay timer at the same time. At the end of the "on" delay of the delay timer it will trigger the pneumatic valve to open, pressurizing the cylinder (which is still held by the latch). At the end of the pulse/pause time (when pulse pause relay is opened), the latch will release allowing the cylinder to extend at a higher rate than would be possible without it being previously pressurized. Now the next part is where I want it adjustable. I need the time the relay on the delay timer is is closed to be adjustable so I can adjust how long the pneumatic valve is opened. Another spec would be that the "on" delay of the delay timer should be about .25 to .5 seconds.

      Sorry if this is confusing. I'll post a sketch today to give you a visual.

      Thanks again

    • oK, so that means "t1" can be ignored and we can just concentrate on acquiring an adjustable "t2", right?

      and the supply voltage will be constantly present, and it's not relevant to the switching procedure, rather we only consider the triggers that may be applied as per the mentioned sequence?

      I'll try to design and post it possibly soon.

  47. Hai,
    I like to connect the above circuit with bathroom fan. The fan should run for 15 mins and off for 1hr. so do I need to change the resistor and VR at pin10 on both the ICs in the above circuits or the same wil be fine??

    • Hai, yes you will need to adjust the shown preset at pin10 for achieving the specified time delays, the upper preset should be set for the OFF time (15 min) and the lower preset for the ON time(1 hour)….the circuit will initialize with the OFF time when switched ON

    • Hai, The resistor, VR and capacitor at pin 9, 10 are used to calculate the ON and OFF timing in the circuit. Correct me if I am wrong.
      And is there any formula to calculate the ON and OFF time?? So I can place specifi value for resistor and cap at Pin 9,10 for OFF and ON.

    • So the formula is Freq = 1/ 2.2RtCt or T out= 2.2RtCt2 X (N-1) ??
      If it is T out means , what is Rt, Ct2 and N?

    • t is time delay between each pulse generated at the selected output pin….Rt, Ct refers to P1 and C1 in the above circuit…N refers to the pinout sequence given by Q1, Q2, Q3…etc check the datasheet of the IC for a detailed info about all these…

    • Hai, I made the circuit. The OFF time I calculated is 8 sec and ON time 10 minutes. When I power ON the circuit, the red light is ON and relay is in de-energized state. After 8 sec, the green light is ON and relay got energized. But after 10 minutes, the relay is not getting de-energize. All the connections are correct. Don't know where is the fault. Pls help.

    • check the pin#3 connection of the lower IC with pin#12 of the upper IC via the diode….may be you have done something wrong in this part of the circuit.

      because after the lower IC counting is over (time elapsed), its pin#3 will go high which is supposed to "poke" pin#12 of the upper IC and reset the whole circuit into the original state.

      I hope you understood the procedure.

    • I checked the two stages separately. i.e I made the upper part separately. when I power on the circuit. The green light is in OFF state and relay is also in de-energize state. After 8 seconds, the green light is in ON state and the relay is also got energized. Then after 8 seconds, The green light goes OFF but the relay is not getting de-energize. I changed the transistors also. But the result is same.

    • if you separate the circuits then how will the looping initiate….without the lower IC's pin#3 triggering pin#12 of the upper IC the circuit will not reset and return to its original state.

      connect the circuit back to the above shown form and connect a third LED from pin#3 of the lower IC to ground via a 1K resistor….

      after 10 minutes, as calculated by you this LED must turn ON, and as soon as this happens the entire circuit is supposed to reset, with this LEd shutting off immediately and the red LED illuminating…the sequence should keep repeating now.

    • Hai, I have found that where is the problem. The relay is not getting de-energize after particular time period due to the red LED with 1k connected to "+ve''. when I removed that, the circuit is working grt.
      Thanks for the circuit.

    • hai, that's very strange and technically doesn't sound OK to me because as soon as the lower IC pin3 goes high, it will reset the upper IC pin#12 forcing the upper IC pin#3 to go low….which will instantly shut off the red LED and also the relay….

      do one thing keep the LED as it is, just add a 3V or 4V zener diode in series with the base of the upper BC547 transistor…

    • In your above circuit, first the OFF timer will work and then ON timer will work. That means , when the circuit is switched ON, the relay will be in de-energize state in the OFF timer and then after the particular time, the relay will get energize in the ON timer. But what I need is , when the circuit is switched ON, the relay should get energize and after the particular time, it should de-energize. For this, shall I change the BC547 as BC557 in the upper IC and connect the ground to the relay directly and +ve to the emitter of the BC557 and collector to the relay. so when the OFF timer is running means the relay will be in energize state and when the ON timer is running means the relay will be in de-energize state. After this change, will this work as I am expecting??

    • Thanks. I made a schematic like that. Pls check it.
      imgur.com/echNkCC
      I connected the collector of the BC547 to base of BC557 with a R2 (10k). Do that R2 is needed or can I connect the collector of 547 to base of 557 directly??

    • Sorry that's wrong….please see the linked article again….there's no BC557….both the transistors are BC547 and needs to be connected exactly as indicated in the related diagram.

    • Actually I want to connect the relay's one pin directly to the ground and another pin to transistor for getting positive to the relay. So the relay should activate by supplying the positive from the transistor. How to make changes for that??

    • why so? it doesn't make any difference whether the relay negative is switched or the positive is switched….the requirement is to switch it ON when the IC is powered

      anyway you replace the existing transistor (in the above diagram) with a BC557 and connect the relay across its collector and ground

    • Hai, I made the ciruit. working good. Thanks for the circuit. The above circuit will work in OFF ON cycle. But I dont want the circuit to work in cyclic process. Once the ON sequence is initialized means it should remain in the same state only until I power OFF the circuit. So what changes i have to do for that?

    • Hi, Swagatam,

      Can you design a timer circuit for me that will allow for a seven day program that can have up to six events per day that may last up to 30 seconds each. It will be used to turn a motor on/off and if possible have a wireless remote to turn the device on/off.

      Thanks,
      Chris

    • I want to set different OFF and ON timing. So the circuit which you suggested above is wont fit for me. I want to run in the above circuit itself. So once the above circuit is switched ON means, first the OFF sequence will starts from IC1. Then the ON sequence will start from IC2. So once the ON sequence is started means it ( the relay) should maintain in ON state only until I power off the circuit. It should not go for OFF state again.

    • Sriram, just disconnect the pin#3 diode cathode of the lower IC from pin#12 of the upper IC and connect it to pin#11 of the lower IC.

    • Hi, P1 will determine the OFF time and P2 the ON time of the relay, when power is switched ON the relay will NOT activate and will execute the off time, after the specified time has elapsed the relay will switch ON and begin implementing its ON time and this will repeat itself as long as the circuit remains powered.

      switching off will not alter the P1/P2 setting and the timing, but the counting of the timers will initiate from the point the circuit gets powered.

      the time setting procedure will need to be done through some trial and error, i might have explained it in one the above comments, you can search it out.

      the relay coil resistance will depend on the relay contact rating (heavier contacts will have lower coil resistance specs), for the shown BC547 transistor the ideal rating of the relay should be between 300 and 400 ohms

  48. sir, is this programmable timer affected by power failure..?, because when power failure happen at my place it can be as long as 12 hours or even longer, will it affect the program?

    • kshitiz, If possible I'll try to update the explanation soon, the component numbers can be seen in the diagram itself, just click the diagram to enlarge.

  49. nas. I very interested with your excellent circuit. By the way. I want to ask you some question. Can this circuit become a chicken/fish feeder cicruit? I want it operate in every 30 minutes and the motor will rotate between 3 to 5 minutes. Any suggestion to upgrade this circuit? Thank you. ASAP..

  50. Hello sir. I'm nas. I very interested with your excellent circuit. By the way. I want to ask you some question. Can this circuit become a chicken/fish feeder cicruit? I want it operate in every 30 minutes and the motor will rotate between 3 to 5 minutes. Any suggestion to upgrade this circuit? Thank you. ASAP..

  51. Hai sir, I am a new follower and tq 4 add me back..sory 4 disturb u..sir I want to know what is the different between 12vdc and supply voltage? Can I change the load to motor? How to connect the supply voltage with relay and motor? And how can I connect the relay in this circuit? Sory sir i dont understand and sorry 4 my grammar.

    • Hi Zahid, the voltage required to operate a particular circuit is its supply voltage, which can be anywhere from 5 to 15V for depending upon circuits specs.

      Please click the diagram to enlarge you will be able to see a relay connected in the circuit and also the relevant connections with its contacts

  52. Bro ,,
    Should I connect module's pin 10 over the display connection? And what is the way to connect the capacitor circuit witch is given on top left of the picture? Need a little clearence bro.

    • sorry bro it's not pin10 but the "clk" pin of the right IC that should be connected with pin15 of the above 4060 IC….

      the top left capacitors in the link indicate the capacitors connected across the supply/ground pins of the IC 4026.

  53. Hey brother,,
    this is tanvir again. I'm here to request you so much that how to add seven segment display with dis circuit , witch will show both times of it. Brother is it possible? And u can trust me that I'll build it coz I had a lot of practice last few months of circuit works. I'll be glad if you accept my request.. regards…. 🙂

  54. Hai, Thanks for the circuit…
    How to adjust the P1, P2 for ON, OFF timing??
    suppose if I want the circuit to activate relay at 6pm and deactivate the relay at 9pm means how to adjust the P1, P2??
    And by adjusting the P1, P2, how can i know that the relay wil get activate at this time and deactivate at this time??

    • calculate the hours between 9pm to 6pm, this becomes the delay of the upper timer.

      next calculate the time difference between 6 and 9pm this becomes the delay period for the lower timer.

      adjust the upper Rt/Ct and the lower Rt/Ct accordingly with some trial and error.

      Rt = combined resistance of pin10
      Ct = cap at pin9 should be nonpolar

  55. hi swagatam
    I tried many sucsesfull circuit from this blog many thanks for that.
    Now i want one circuit which can work as occilation like 1/2 second on 2 sec off circuit is on 12 volt DC supply can you help me for this project.

    • Hi Ashoke, thanks!!

      you can simply use a 555 IC astable circuit for it, and set its mark/space ratio accordingly by referring to an online 555 IC calculator software.

  56. Sir
    I would like to control high must light.
    My requirement is early morning off at 6.00am & evening on 7.00pm.
    Is this possible through this ckt.

  57. Sir,
    I need a circuit that switches the relay on for 3 minutes for every 5 minutes interval.I mean that 5 minutes after powering the circuit, the relay should be switched on for 2 minutes and off again. After 5 minutes again the relay should be switched on for 2 minutes and continue the cycle. Can this circuit be used for this type of application? Please try to giv early reply as I have to make this circuit within two days and present it at mycollege……THANK YOU SIR…

  58. Hello
    I need a timer where I can program it precisely several days before. I am building a camera that will be close to the launch pad and will take photos of the launch of an Atlas V. If there is any way I can do it, suggestions would be greatly appreciated.
    Thanks

  59. Sir as per your suggestion I assembled the circuit but mistakenly I connected the 10uf cap from positive to the pin 14 of the ic4017 and 100k resistor from negative to pin 14. It was responding well. Then I replaced the 10 uf cap with 0.1uf cap. The response was still awesome.
    The idea for latching Output is really nice one by urging scr. For this purpose can I use one of your circuit configured around SCRs that is Code Lock Circuit.

  60. Sir my question consists of two parts
    1. As I have earlier stated that the ic 4017 responds well with an oscillator(555 ic) but doesn't responds well with manual input clock. I connected pin 14 to ground via 100k resistor as suggested by you but in vain. Now what should I do?
    2. I need ic 74LS164 to produce serial outputs via manual switch. I read your suggested post but it cannot meet my need. Sir kindly help me I need both these circuits. Thanks a lot.

  61. thank you sir i need the above mentioned ic this is the exact device i was looking for.today i read about it but i would like you to explain it in your own way so i could understand it well. thanks a lot once again.

  62. Thank you sir I.ll try it.Sir i need a circuit similar to the one with ic4017 but the problem with ic4017 is that whenever pulse is given one output appears and the previous output disappears. The one I need should be opposite of it. I mean when i give 1st pulse there should be one output but when i give second pulse there should be two outputs and when i give 3rd pulse there should be three outputs and so on. No output should disappear.the pulse pin should be single like ic4017 Thank you

    • Mujahid, the IC 4017 will not produce latched outputs, its sequence will shut the previous output as it proceeds in the order.
      For your application you would need the IC 74LS164, this will produce latched outputs as its output sequences.

  63. Sir kindly help me the ic4017 gives its sequential output when I am using oscillator circuit (that is 555 ic) I mean it is all ok with an oscillator circuit but when I manually give a positive pulse at pin 14 of 4017 it does not respond well please I need it

    • Mujahid, did you connect the pin14 to ground through a resistor? you must do this in order to make it respond to manual switching.
      connect a 100k resistor from pin14 to ground and then trigger it with a positive pulse manually, it will surely respond.

  64. Sir the circuit is very nice. I made it successfully. I would like to suggest to those who are trying to make it they should make it in such a way where each ic should work individually and should not be interconnected. When both ic start working individually then they should be interconnected. I myself applied the same method and succeeded. Am I right sir?

  65. Hi sir,
    i assemble this circuit but not work properly. It shows that, relay start when power is applied but not Off as i adjusted the pot. I used polyster 1uf/250v capactitor NP. I dont know where is problem please guide me how can i take tests on circuit for example any voltage point.

    • Hi Ashok
      I have designed and tested this circuit myself and it worked flawlessly.

      The relay should not activate when switched ON, rather when the upper IC time has lapsed.

      Something's severely could be wrong with your circuit connections.

      Put an LED with 1k resistor at pin7 and ground of the ICs, when the particular IC is activated this LED will start flashing indicating proper IC functioning.

    • sir i check this i put 1 led with resistor at IC1 & IC 2 pin 7 both LED flashing at same intensity 3 flash per minute when power is supply & relay activate instantly. can you tell me where is my problem.? one question is that both 1uf/25v capacitor is Non polar ( polyster) & 0.1uf cap is ceramic? I used these parts.

    • Ashok, replace the capacitor in the upper section with 0.22uF and the lower with 0.1uF and now check….this modification will give quick switching and help to verify the functioning.

      Connect another LED with the base of the relay driver transistor….check its response….relay should NOT activate on power switch ON

  66. hi
    i m regular reader of your blog. I want the circuit as per following condition.
    1) When power supply is on then relay on after 3 min.
    2) After 3 min relay stay on for 2 hour then off even after power get failed at power on switch and continues run by 12 volt by load connection for 2hour.
    can you guide me for this project.

    • you can try the above shown circuit.
      adjust the lower section for 2 hour and the upper section for 3 min.

      for battery backup connect a parallel battery supply through a 1N4007 diode. the mains power supply voltage to the circuit should be slightly higher than the battery voltage

  67. Also please what frequency would you expect the cycle if both pots were at their lowest resistance? (given correct components were used as per your diagram)

    • Yes pin#15 could be too slow with its blinking rate especially when the ICs are set with timing over 5 minutes, so won't serve as an effective indicator, I have updated the diagram with LED indicators for the respective indications.

      The frequency formula is
      F = 1/2.3RC….where R is ohms and C is in Farads

    • Thanks. However I'm still having problems with it. Would a correctly wired circuit illuminate the red LED whilst waiting for first timer period to trigger the second which will result in the red LED turning off and the green LED illuminating (as well as obviously closing the load circuit via the relay)?? I would just like to confirm this is the intentional use of the additional LED's. Thanks again for your help.

    • Yes, the moment the circuit is switched ON the red LED will light up, it will stay illuminated as long as the upper IC counts and will shut off once the upper time interval lapses.
      This will prompt the lower IC to begin counting with green LED now being illuminated.

  68. Thanks Swagatam,

    I'm negative at the upper ic pin #15, you mention in your upper post that pin#15 should give indication of functioning circuit, can you expand please on this circuit diagnostic?

    Thnaks again.

  69. Hey mate,

    I am trying to understand the circuit with regards to the relays connection into the circuit. I realize this is perhaps 101 stuff however it is a hurdle for me at this stage in getting this circuit to function for me. Does the diode connect directly across the coil pins? How are the NC and NO pins connected? Is the common pin connected? Thanks your help is appreciated.

    • Hi Jason, it may be connected directly across the relay or anywhere in the PCB, it doesn't matter as long as it joins with the relay coil in the shown manner, that is cathode to the positive of relay coil and anode to collector side of the relay coil

      NC or NO should be connected with the load via the supply voltage as per the requirements such that when it operates it makes or breaks the supply to the load alternately.

  70. Hi Swagatam,
    I am trying to build a circuit to help me with giving speeches. I have a bunch of parts already and I would like to use them if possible. I want it to have an On/Off switch to power the circuit and a Start/Stop button as well as a Reset button. I would like for it to light a Green LED after 5 mins, then turn off the green LED and light an Amber LED at 6 mins, and then turn off the Amber LED and light a Red LED as well as sound a buzzer at 7 mins. I would also like to have a seven-segment display show the elapsed time. Let me know haw feasible this would be. Thanks.

    • Hi Charlie,

      Yes it can be done, in your previous comment I have suggested you the required PWM controller circuit. You can simply power that circuit via the relay contacts of the above circuit, so both get integrated for the intended results.

  71. Dear Guru …
    I need circuit for time limiter to use for public speaking.
    Say if a teacher has one hour to speak in the class then the timer will show a green light starting from 60 minute then counting down to 0, but before finish the yellow light will turn on to remain a teacher that the time almost finish, it can be 3 minutes before to 0, finally when the time is over the red light will be on, it means that time for the teacher is finish.

    Thanks & Regards,
    ilman.gumilar@gmail.com

  72. hi dear…
    can i use the above circuit to keep relay ON for 5 sec and keep relay OFF for next 30 minutes..and after 30 minute the ralay automatically ON again for 5 sec and thin OFF for 30 Minutes and this process repeat again again

    • THis is not a blinker, rather a timer circuit.

      Anyway if you are using it as a timer, do the the following:
      You can remove the transistor/relay assembly and connect one of the LEDs LED across the existing 1K resistor and pin#7 of the IC. Anode will connect with 1K and cathode to pin7.
      For the second LED, you have to repeat the procedure, connect another resistor at pin3 of the IC, connect the LED across the free end of this resistor and pin7 of the IC….polarity same as explinaed for the first LED.

      The LED cathodes are connected to pin7 so that they blink when the time elapses

    • I'm hoping you can answer a question asked earlier. "Can I connect the load directly to the circuit instead of using a relay?" Or if not, can i use the same 12v power for the load/relay side and the timing circuit side?

      I am wanting to use this circuit to run an air circulation fan (12v computer case fan) system in a cooling unit. But a 555 oscillation timer runs too much. I only need approximately 1 min on / 30 min off run time for the fan.

      Thanks, Chase

    • A 12V fan can be directly connected across the transistor, but it will need to be upgraded to a higher rated (TIP122) transistor instead of the shown BC547.

  73. Hi sir,
    I need a circuit for a motor that pumps water for appr. 15sec daily. I would like to program the timing(15sec) in MC. Is it possible.. can you please help

    • HELLO SIR..
      SIR THIS HELP IS ABOUT COMPUTER LOGIC DESIGNING SUBJECT.
      SIR MY TITLE IS TO MAKE DIGITAL CLOCK USING COUNTER.
      BRIEF DISCRIPTION : I CAN USE DIFFERENT GATES(AND,OR,NOR E.T.C) AND COUNTER .PIC OR OTHER IC PACKAGE IS OT ALLOWED .
      PROJECT IS ABOUT 25 MARKS. THIS MEANS THIS SHOULD NOT BE SIMPLER ACCORDING TO MADAM.I HOPE SIR YOU UNDERSTAND MY NEED
      I HOPE YOU IS THE PERSON WHO CAN HELP ME..
      THANKSS …..

  74. I really hope someone can help me……

    At the office I need one answerphone message during office hours and a different message out of hours. At the moment these are switched manually however on the odd occasions when I have to go elsewhere before going into the office, the out of hours message stays on until I can physically switch it over.

    I thought of creating a standard programable timer that connects between the wall telephone socket and the two answering machines that can switch one machine off whilst switching the other on and vice versa.

    I originally thought of just using electric timers as can be bought in a shop however if the power is disconnected to an answering machine then it is reset and may not work properly when switched back on without physical intervention. So my thought is that both machines remain powered up but the switching actually happens on the telephone line.

    I think it should be straight forward however I have not been able to find anything that can achieve this. Any help or circuit design ideas would be very much appreciated.

    Thank you.

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