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How to Make an Incubator Timer Circuit – Egg Incubation Optimizer

A timer circuit design which could be used for turning the position of the eggs in an incubator between predetermined intervals of time was requested to me by one of the keen readers of this blog, Mr. Eugene. 

The requested circuit has been exclusively designed by me and published here, 

Let’s hear the whole episode:

“Good day,

I’m raising cocks for derby and I have hen that is laying eggs. For the hen to continue laying eggs, I need to incubate the eggs. I have researched incubator designs and parts and I have already assembled a simple one. I have a digital 220V ac thermostat and in order to protect it, it will only have to drive a 220V relay. This one already worked well.

Now I have an additional info that the eggs have to be rotated or moved upside down 3 times a day in order for the eggs to hatch well. I am planning to make a rows of eggs holder chained or builted together driven by a motor such as electric fan swing motor. Its strong and moves very slowly and I think its quite enough. This 220v ac motor will be driven by a 6v dc relay. Now I need a relay driver circuit and a timer circuit that wil trigger the relay driver more or less every 8 hours for approximately 3 seconds only.

I may not have enough words to reach 300 but I think my intention is clear enough. But if the blog requires 300 words, I will try to extend my explanation.

Thank yo very much and I hope you can help me.

The circuit of the proposed incubator egg timer and optimizer is given below:

P1 should be adjusted for the long 8 hour duration and P2 for the short 3 seconds duration.

Circuit simulation:

Looking at the circuit diagram we can see that it consists of two identical IC 4060 stages which are coupled across each other for implementing the proposed actions.

The upper timer stage is intended for producing long time intervals and therefore its output is taken from pin #3, while the lower IC generates smaller time intervals and so its pin #15 is chosen as the output.

When power is switched ON the following things happen with the circuit:

The 0.1uF capacitor resets the upper IC so that it can start counting, during this period its pin #3 is at logic low which keeps the relay driver stage switched OFF, also the lower BC547 is kept disabled, which keeps pin #12 of the lower IC at high logic which in turn renders the lower IC inactive.

After the predetermined period is lapsed, pin #3 of the upper IC goes high, this switches ON the relay driver stage and also the lower IC pin #12 gets reset, this toggles the lower IC into counting mode.

After the predetermined period, pin #15 of the lower IC becomes high, which sends a logic high to the reset pin #12 of the upper IC, resetting it back to its original position……the cycle repeats, and goes on repeating as long as power is available.

The lower section can be upgraded for generating higher time intervals at par with the upper section by replacing pin15 with pin3 as already done in the diagram below.
The relay contacts are wired up to the motor for shuffling the egg orientation.


  1. Hii,

    The circuit presented in this article is intended to be used for the same purpose as required by you, just connect it to a pwm controlled motor, adjust the timings and that's it, it will start working.

  2. Yes that's true, but that will some mechanical arrangement, like automatic pressing of a switch by the motor, when after it makes one cycle or two cycles etc. I will have to think about it.

  3. hi sir,do you prepare already the mechanical arrangement that you've said for the positioning of the trays?thank you please do it for us.Thank you

  4. As you know my expertise lies with the subject of electronics so it will be difficult for me to investigate a mechanical system….but if something innovative strikes me i'll remember to share it here…


  5. Can some please provide me with a schematic of simple thermostat (temperature controller/stabilizer) which switches off the heater at above 102F and switches it on when temperature reaches below 99F.

    Designing can be either using Digital logic or purely analogue.

    please email that to me at shaikhshan@gmail.com

    Thanks alot.

  6. hi sir.i want to try this circuit for my new automatic incubator..do have pcb layout for this circuit?? thankz advance for sharing………..

  7. Ok sir,about this 1uf/25v,electrolitic cap,or ceramic? Because 1uf in non popalar elec.cap,is not available on my location, any replacement for this cap?, its ok to use 1uf/25v with polarity? Thanks

    • will do….the time period is directly proportional to the product of the values of R2+pot and C1. As these values are increased, the time delay also increases….

  8. hi sir i hve made this will u please tell me that after how many hrs rely will close the contact???? im connecting it to 12 volt dc aource nothing is happning… i have wait about 2 hours but nothing is going on wht should i do.??? i have use 1uF50 volt capacitor because here is not availblity of 1uF25 volt capacitors plz guide me

    • Hi Nizamani,

      You will have to find and set the time through practical trials and errors…

      For confirmation connect an led across pin#15 and ground via a 1K resistor of both the IC, this LED should generate different blinking rates corresponding to different pot positions.

      If this happens means your circuit is working normally and will activate the relay after the set time has elapsed.

      By the way the capacitor should be a NON-POLAR, electrolytic type will not work

  9. hi sir.
    is it possible that the circuit will energize the relay for two hours and then de-energizes it for two hours equal intervals? how can i do it? pls help.

    • for equal intervals of any period you won't require two ICs, you can do it with just the upper IC circuit.

      remove everything that's below the lower BC547 along with the lower BC547 and its base resistor.

      Just adjust the upper P1 for getting equal 2 hour ON/OFF relay/delay cycle

  10. Hi Swagatam

    First of all thanks for circuit and My one has serious issue …. Even I kept P1 in maximum value it will ON after 7 hours and after that only one hour intervals it will on. Pleas help me to solve this issue. waiting for your kind answer

    Thanks Chandana Aponso

    • Hi Chandadna,

      The timing can be extended by increasing the values of the Pots and C1s…..you can try 1M pot instead of 100k and put a couple of more 1uF caps parallel to the existing ones, this will provide you with a higher timing range.

  11. Dear Swagatam

    I am looking for ELECTRONIC LOAD CONTROLLER fro my hydro turbine single Phase and three phase. Please be kind enough to help me.


    Chandana Aponso

  12. Dear bro… I'm a completely new hobbyist for electrical projects…. and I'm gonna make an incubator for my pigeons and ur circuit of auto egg turner is just awsm…. but as because i'm so new here i got the positive power connection but witch is the negative power connection pls mention it for me… and i completed this circuit on a breed board but when i connect with 12volts with positive and earth connection my lower ic gets hot and the heat keeps increasing …. so pls tell me why this is happening witch will be so great full to you…Thanks, Tanvir

    • Hallow bro I'm so grateful to u for ur reply its now working well.. 🙂 and now i need to know also about egg turner circuit, witch one is the negative port to connect with power ? is these 4060 ics are cmos or another ?unluckily in this circuit my lower 4060 ic is also getting hot and the heat keeps increasing, wht could be the problem? and what is the procedure to make caps parallel? if u pls explain I'll be grateful, and i am making an incubator by ur circuit for my pigeon eggs, for wht humidity is so important, so can u pls provide us a programmable humidistat or hugrosta's easy and simple circuit diagram witch can produce humidity to fixed level in incubator chamber by an watering source? coz it will make the incubator perfect and complete. Thanks a lot… 😀

    • That's great Bro!
      In the above programmable timer circuit, the line which shows an "earth" sign is the negative line.

      Yes, the IC4060 is a CMOS IC.
      The IC will become hot under two conditions, if the supply voltage goes above 16V or/and if its outputs are shorted, so you would want to check for those….
      I will surely post a simple programmable humidity controller soon in this blog and let you know.

    • Thats just great bro…:) I'll be waiting for Ur programmable humidity controller eagerly witch will make my incubator completed as early as u give me the circuit and pls draw the circuit with details of ports, connections and component's picture so that we as a new comer can understand that easily and enjoy Ur help ,, I'll checkout the fault and of timer circuit and let u know… 🙂 Thank u so much brother,, R U Bengali ?… 🙂

  13. Dear bro thanks a lot for the circuit of humidity controller,, I'll make it but I'm so disappointed that i couldn't collect caps 1uF/25volt non polar or .47 uF non polar so that i couldn't make the egg turner circuit… and by the way, my name is Tanvir… 🙂 Thanks

    • Dear Tanvir, no issues you can other values also for the capacitor, it should be non-polar that's all….for increasing time delays you can increase P2/R2 values to any desired higher levels.

  14. Dear Swagatam,
    Is it possible to identify the switching time interval of the relay by seeing the the blinking rate of the LED's connected across pin 15 and ground if both the ics. i have used 1u 63v capacitor is there any change in the time interval if the volt rating of the capacitor increases.

  15. Hi bro,
    its tanvir again, i collected some 1 uF and .1 uF non poller caps but there volt value is different and still the circuit is not working properly, i am sending capacitor's pics and 100 K verriable resistors and its connected pins picture also to ur "homemadecircuits@gmail.com" e-mail add,
    pls see it and tell me that are these correct components? Now the main thing is i build the circuit and when i'm connecting it with power the 400 ohms SPDT relay sounds energize and keeps ticking after3 seconds for 1.20 minuets then it stops ticking and restart ticking after 1.20 minuets again and it continues, so what the hell is happening and what is wrong i've done? and what is the fault and solution pls elaborate details with pics my dear brother because i cant do anything until i make this device, Thanks bro… 🙂

  16. Dear Swagatam,
    Thanks for your reply.I would like to know, what changes i need to make in the above timer circuit to get the relay to be switched ON in one hour interval and cut off after 10-15 seconds.

    • Dear Liju,

      you will have to do it with some trial and error.

      You can do it by initially replacing R2, P1 with a 33k fixed resistor and see what time delay it produces, if it gives say a 50 seconds delay would mean that a 66k would produce 100 seconds delay and so on……the response would be very linear.

  17. i do believe in ur circuit but don't know why i dont have confidence on my parts so that i sent some pics of my parts to ur "homemadecircuits@gmail.com" this e-mail address, did u get it if so then pls reply me that those parts are correct, so I'll have confidence again to rebuild it … , I'm using 400 ohms SPDT relay, is this correct ? … thanks bro .. 🙂

  18. Hallo brother,
    It seems that i'm such an unlucky person for this device, coz i made it but it's not working, at first i made it and connect it with power and both of the led and relay turns on and doesn't response with pots,
    brother i know there must be a connection problem but the thing is where the connection problem can be if u pls mention some of the miss connections or problems for this troubles i can check it and sort it out… pls brother mention some problems witch could be with this. and is the 4060 ic are sensitive.? should i forget to built it bro?… 🙂

    • hello bro,
      i think you should rebuild it and this time make and test the stages separately.
      First build the upper stage and check it's response and then go for the lower stage.
      Both the stages are actually identical, simply cascaded to work in tandem.
      The lines connected with the earth symbol must join with the negative of the supply.
      The positive supply must not exceed 15V.
      No, 4060 is not at all sensitive or vulnerable, unless connected wrongly.

    • Hey brother, its tanvir again , u know wht? i was so frustrated that i couldn't build it, but last night i tried once to build it and and just for interest i connect a led to pin 7 of upper ic via 1k resistor to negative point and i see it is blinking i got excited and keep wiating wht happens and after sometime i see the relay activates… but now there is a problem ,, when i connect a motor with the relay than power the device than the relay activate and turns off instantly …. but when is the motor disconnected the device works properly .. wht could be the problem ? pls mention the problem with details solution so that i can sort it out… thanks brother… 🙂 i am using 400 ohms SPDT relay .. but wht is the correct relay should be??? pls elaborate..

    • congrats bro, keep it up.
      is you motor dropping the supply voltage while switching ON? in that case you will need to use a higher amp supply input.
      you can also try putting a 220uF/25V or bigger capacitor parallel to the motor wires and check the response.

  19. Dear brother ,
    i connected the led with pin 5 maybe that was the problem now i connected the led with pin 15 and the motor is working properly..now give me some safety instruction for the device and should i connect any capacitor with the motor's pins? coz i saw it in a remote controlled toy car. and is it possible to add variable resistor instead of 100 k resistors so that we can change the resistance from 10 to 100 k when we need to ? if so wht power of resistor should we use and how to connect it ? thanks … 🙂

    • Dear brother you can connect a 100uF/25V capacitor parallel with the motor wires, and also a 0.1uF directly across the IC supply pins, a pot can be used for setting the time intervals as shown in the diagram.

  20. brother , how to set a nob with the variable resistors and how to measure the interval periods of this device , coz its really tough to wait for long to measure the times of the divice.. 🙂

    • this you will have to do with some trial and error, make a dial behind the pot knob and mark the minimum, center, and maximum delays obtained across the entire dial radius, once this are fixed the intermediate delays can be marked simply by graduating the dial linearly.

  21. dear bro,
    thanks for the suggestions, but can u pls show the diagram of 0.1 uf caps connected with the ic pins… or witch number pins will be connected with the cap? and unfortunately i couldn't find any 25v caps here, i'm using higher volts caps, will it harm the device or its activity ? Thanks

    • bro, connect it directly with the pins16 and pin8 of the ICs…………it surprises me how you are not able to find the supply pins of the IC which are clearly shown in the diagram and which are already connected in your prototype??? higher voltage caps will be fine…no issues.

    • presently don't think about it bro:) when you are not able to make such a simple circuit which is shown above, how would you be able to make a complex digital circuit integration with the above.

  22. thanks bro, it happened as i told u before, that i am totally new in this site,,, and i appreciate ur comments ,, as because u are now my honorable teacher.. Thanks

    • dear Rizsha,

      red indicates upper timer is counting, green indicates the lower is counting.

      if none of them are lighting means something's wrong with your circuit.

  23. Hi sir..can I use this.circuit for a hydroponic irrigation system? All I want to do is to run a mini water pump of 12v every 3 hours for 20 mins….. will this circuit do the needful???
    Thank you

  24. hi sir could you please guide me to solve my little problem? i have tested the circuit on project board and it worked but i couldn't set the time interval to be different, i upgraded the lower caps and resistor to be higher but it wasn't changing the time interval. the relay was only on about 3 minutes and then of about 3 minutes again. i need 20 seconds on and 2-3 hours off. thanks in advance

    • Hi rood, something's not right in your circuit for sure.

      connect an LED with a series 1k resistor across pin7 and ground of the lower 4060 IC. (cathode to ground)

      As soon as the red led shuts off this LED should start flashing indicating that the lower stage has been activated.

      If you don't see this response could mean an incorrect wiring or faulty components.

  25. you right sir i just made an error in wiring the components. i now have to tell you that the circuit is working properly now it's great. i followed your instruction and replaced the upper pots with 1m pots and connected the lower 1N4148 diode to pin 6. now i have 1 hour off and 15 seconds on. now i'd like to increase the upper timer to be 3 hours. i like your circuit thank you very much sir.

    • that's great Rood, you can increase the upper IC timing by connecting more number of capacitors in parallel with C1, all should be strictly non-polar type.

  26. Sir I did the circuit but I only need 20 mins on the upper ic… hw can I get it done? And I couldn't find 1uf/25v caps bt I only got 1uf/1000v non polor. Will this make a problem? And does the 0.1uf cap has a voltage rating?

    • Srishan,
      1uF/1000v will also work, use a 1M pot for the upper P1 and set it to get the required timing by some trial and error.

      0.1uF can be a 50V disc capacitor.

  27. Dear sir, I made the circuit and I'm so happy that my circuit work fine more than I expected…I replaced the pots with 1megs and in order to check the blink rates of both the ics I used two leds on both 7 pins of the ics with 1k resister,
    And to my dear friend who has commented on this circuit. Plzz take a bit of time to carefully study the diagram and make it… if you do exactly do as said believe me it works 100%
    And once again thank you so much sir 😀

  28. hi swagatam, i tried to build the circuit, when the power applied the relay activate, the red LED illuminate, the green LED off, On pin #7 I connected 1k resistor and LED to the ground on both IC`s, they are both blinking, after 30 mins the red LED Off and the green LED On 30 seconds, but noting's happen on my Relay, after 30 seconds, the green LED Off the red LED On, but the LED on upper IC pin #7 is not blinking, the lower IC still blinking.

    I used 104 cap ceramic type and 1uf/50v cap non polar similar to this -> http://us.100y.com.tw/product_jpg_original/A011025.jpg, is their something's wrong with my circuit?

    • Hi unknown, when power is applied the relay should NOT activate….may be the circuit is getting latched at the onset itself….try increasing the 0.1uF at pin12 of the upper IC to 0.22uF or higher and check the response.

    • I rebuild the circuit, when power is applied, RED On, Green Off, pin #7 Blinking, Relay was not activated, after 30 mins RED Off, Green On, pin #7 stop blinking, but still the Relay was not activated,. i replace all my caps 104, 105 to Mylar type capacitor

  29. i buy new of components 🙂

    what if i only want 2 hour On and 2 hours Off? i will remove the Pin #3 and 1N4148, Pin #8, Pin #12, 1M, Pin #16, and BC547 and it base resistor?

    • for equal time durations, you can completely eliminate the lower IC stage along with the lower BC547…not the upper BC547 stage…

      The 1N4148 will also need to be removed for obtaining a sustained ON/OFF response from the IC.

  30. Thank you very much Swagatam! IT WORKS! can I remove P1 and replace R2 with my desired resistor value to get my desired timing? Im a programmer swagatam and no background in electonics, thank you very much for guiding me,.. 🙂 what is the use of 1N4007 diode in relay? if i have multiple relay do i need to put diode? can i add fuse or any safety features?

    my next project is your Solar Battery Charger, moving to the next level hahaha,..

    • You are welcome Unknown! yes P1 may be replaced with a suitable resistor for enabling the intended fixed oscillation periods

      The 1N4007 will protect the driver transistor from relay coil back EMFs, for multiple relays in parallel a single 1N4007 would be sufficient, individual diodes may not be required. However the transistor may need an upgrade if the relay count is over 2. You can try a 2N2222 or a 8050 in place of the shown BC547.

      A fuse is not crucial and may not be required for such low voltage DC operations…

      wish you all the best for your next project…keep it up:)

  31. Dear bro,
    I made the display driver its working great,, and I'm so happy for it, but bro is it possible at a display witch will show the set time when I'll turn the pots? Thanks

  32. Hi bro,
    its tanvir again, ur great device i made last time was working so good for long but suddenly i see its wrkin wrng, whn i power it up relay activates, and relay transistor bc547 gets extreemly heated. I changed the trans i changed the 10k resis, even changed the 4060 upper ic, but it still hving the same problem, i tried a lot to solve the probs bt couldnt do anything, so can u please help me to solve it? Thanks

    • Hi Bro,unless the input voltage is increased above 18V or there's some short circuit in the circuit, it's unlikely to become hot or malfunction, or may be the ICs you have used are not of good quality.

      Try Using a 12V AC/DC SMPS adapter instead of transformer.

  33. Hi sir,
    Im a new hobbiest, i was looking for a timer for long and i found it in ur blog, but after i made it im having some common probs, that is when i power it up relay activates and red led on, after some time grenn led turns on but red does not fully off ,it deems but keeps on and no change to relay, im using 10k for R2 and 10 k pot for p1 for both ic, my ics ar new and good quality, i made it several time bt problem is always same, and there is no probs wit any resistor,, sir pleaae tell me what can i do?

    • Hi Riya,

      Your circuit may not be correctly assembled, because on power switch ON the relay should not activate. The relay will activate only after the upper IC time has elapsed, and deactivate when the lower IC time has elapsed.

      something is wrong in your circuit, may be the transistors are not connected correctly.

      On powering the REd LED will be ON, never both.

  34. Dear sir
    Here how i built ur circuit, at first i built the upper ic option and when i power on it was working 100 percent ok, after that i attach the liwer ic option nut after that i connect a led across negative and upper ic pin 7, the led blinks as well but nothing happen with relay or liwer ic ,i added abrand new ic for lower portion, but still works nothing, i waited for long long time but result is same,, is the problem with 4148 diod? Or how can i solve it ? My lower ic ppt is 10k and r2 is 10k where upper on is 100ksl s, thanks.

    • Dear Riya, you must do exactly as given in the diagram…the resistors should be 100k for the pot and 2M2 for R1….the diodes are OK and must be included…connect LEDs in series with the transistor bases, that is in between base and the 10K resistor of both BC547s….the LED will indicate when and how the transistors are conducting in sequence or if there is any mistake in the IC function..

  35. Hallo sir,
    Im having a prob, at first i made the circuit without led and keep it for aomedays and it was working very good, after somedays i try to add the led but when i power it on relay activates with red led, but when i disconnect the red led the device works good again, what could be tje problem sir? Thanka

  36. I use 12 volt dc transformerless power supply, when I first operated it, the red led is on but its dreary i think because its current input low, after that i have been waiting long and nothing happened, the red led still on. Whats going on sir? I use 2M for R1

    • check with a 12V AC/DC adapter for confirming the circuit operations, and anyway a transformeless power supply might not work, it could produce wrong results and might not be capable of the driving the relay….
      2M is fine for R1

      C1 must be non-polar

  37. hi sir i use adaptor 12 v 1 a. Nothing diffrence with the firs time, led on and dreary, when i connected led across pin 16 and ground via 1 k resistor, this led on and brightly. When i connected led across pin 15 and ground via 1k resistor nothing happened led still off, would you like to help me this issue,,

    • Harvest, initially the red LED should be ON brightly, and when the time elapses for the upper IC, red LED should shut off and green LED should illuminate….if connected at pin16 or pin 15 the LED should flash

      I think something's not right with your connections or the circuit.

  38. I have built it again, i think the upper ic work well, i check with led pin 15 and it blink and i have changed pot with 500k and it work good. But the lower ic become touch sensor. When i touch the output ( NC/NO) relays wired, the led lower ic blinks but when i do not touch it, blinks stop and next on like that, what happen on my circuit, please help sir, i am new on elektronics

    • the lower IC will not function until the upper IC has finished counting, …..in other words when the lower BC547 is triggered only then the lower IC will start functioning……in other words when pin12 of the IC is held at the ground potential only then it will start counting and functioning.

    • with a multimeter in the diode range check which outputs of the relay close or open while the timer is counting or finished counting….with this info you can connect the motor with these contacts accordingly

    • hello Dinesh,

      will do, however P1 and the 1uF parts decide the time length…220K , and 470K are fine, but try using more numbers of 1uF/63 in parallel to get higher delay ranges. it must be non-polar

  39. hai bro, can u send the pic circuit board i cant understand your picture so please send some pics of buided circuit board and limit switch s pics please thanks in advance

    • Balu, this is a timer circuit, no limits are included here, you may have to adjust the speed of the motor to match with the selected timing interval of the circuit

  40. DEAR SIR, Can u please adjust the circuit for every 2 hours interval switch on 3 seconds only for my homemade egg turner. I am new here. Please let me know the resisters for UPPER IC (2 hrs interval) also capacity of potential meter to be used. Also let me know which resisters can be used for LOWER IC (3 seconds) and also explain about the capacity of relay. I am going to use 12v 3.7 RPM motor

    • Dear Michael, It won't be possible for me, because it will need to be done with practical experimentation.

      you can do it in the following manner:

      in the above given set up you can keep the P1 short circuit so that only R2 becomes the timing component.

      Switch ON power and using a stop watch check after how many seconds the green LED lights. Note this down and from this data you can find out the other required timing cycles using the following simple cross multiplication;

      P1+R2/R2 = x/Recorded Time, where x is the desired time interval.

      for example if you got 10 seconds from the above experiment and the desired interval is 2 hours (720 seconds), then the formula could be solved as:

      (P1 + 100)/100 = 720/10
      P1 + 100 = 7200
      P1 = 7200 – 100 = 6200K

      Remember the above calculation is just an example, and the figures are arbitrarily selected.

    • it's a DC motor,

      the above circuit uses a relay, which means you can use any motor, does not matter whether it is a DC or AC, you just need to connect the relay contacts accordingly with the relevant supply input and the motor

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