The post discusses a simple and effective industrial timer circuit which can be universally used for most industrial and home timer based applications. The idea was requested by Mr. Vasilis K.
Technical Specifications
I have a question regarding the 4060 ic wired as "one shot timer." If it can power on the two monostables from the pellet burner circuit, output will be taken from pin #3 which is the last to count to the C1 stage, will that work?
When power is applied to the circuit, the first 2 stages should stay low until the time has elapsed. Pin #3 should be set to activate the cycle, so when I leave home in the morning, I will be starting the timer via the thermostat.
Then when I get home, the burner should be running.
To be more precise, as per the circuit design there are 2 monostable circuits (Stage 1&2) when power is applied via a room thermostat it activates the cycle (Stage 1&2),
My request is when power is applied after the predetermined time of the 4060 has elapsed, is to activate the cycle (Stage 1&2), as there is no need for the burner to run when no one is around, plus this would be ideal as it takes about an hour for the water temperature to reach at 75 Celsius.
The Design
The IC 4060 is an excellent option when it comes to any timer based industrial or home project. This chip being a CMOS device is highly accurate, and is able to generate time delay periods of as high as upto 10 hours with reasonably good accuracy, after this limit the accuracy tends to drift a bit.
Although the IC 4060 generates a fixed 50% duty cycle astable type of oscillations at its various outputs, it can be configured as a one shot timer, as explained in the present article.
Referring to the shown simple industrial adjustable timer circuit, we can see the IC being the central main component of the whole design.
When power is applied or switched ON, C2 momentarily pulses pin#12 of the IC and resets the timing so that the internal oscillator begins counting from zero, moreover the IC can be reset at any moment during the counting period by pressing the given reset switch.
While the IC counts, the output which is being used (pin#3 here) is held at a low logic level or a zero voltage, which keeps the TIP122 switched OFF
Now as per the setting or selection of R2, P1 and C1, as soon as the set timing elapses, pin#3 goes high, switching ON the transistor and allowing the power to pass to the connected circuit, which now activates.
The feedback diode from pin#3 to pin#11 instantly locks the internal oscillator and latches the circuit so that the circuit freezes in that position until the reset switch is pressed for initiating a new cycle.
Circuit Diagram
For heavier loads, the above circuit may be upgraded with a relay for identical results but with much higher load current handling capabilities.
Feedback from Mr. Vasilis:
Hello swagatam!
TESTED & WORKING, really happy with the outcome, i used the 2nd circuit with the relay as i didn't have that specific transistor, that would be my last request for you, i hope i wasn't that much of a pain, again really thankful for all the help and effort, god bless you!!
Regards
Vasilis K.
Godson says
Hello sir Swagatam,
I have connected the circuit as shown in the post with the indicator LED for testing but rather than staying off, the LED keeps blinking before staying on and then resumes blinking again, and then stay on. The process continues indefinitely. What could be the problem sir?
Swag says
Hello Godson, that shouldn’t happen, because initially the red LED must stay OFF, and as soon as pin#3 goes high after the elapsed period the positive from this pin should latch pin#11 stopping the counting and causing the LED to become solid (pin#3 latched at permanent high).
you can try changing the pin#12 0.1uF cap with a higher value capacitor and see if it helps…also while testing power the circuit from a good 12V DC power supply.
Godson Ugo says
Thank you very much for this post sir. I have been looking for it for some time now. I want to design mine in such a way that I won’t be needing the reset button. I want it to work in such a way that anytime power is applied to it, it activates the Relay for 3hours and then deactivate the relay after three hours until the power source is removed. And when the power source is applied again, the process repeats itself. Here are my questions,
1. In the comment, you said that in order to keep the relay activated during the timing period, the BC547 should be replaced with BC557 and that the emitter should be connected to the positive supply and relay-diode assembly should be connected between the collector of BC557 and GND. Please I need you to confirm that sir.
2. What value of P1 and C1 should I used in order to achieve 3hours of timing? If there is a formula for it, kindly help me with it.
Thank you for all your efforts sir.
Swag says
Hi Godson, yes that’ correct, use PNP to initiate the relay with power switch ON, the push button is for resetting the timer to zero, it is not required to start the timing, the timer will automatically start as soon as power is switched ON. the reset button can be used to reset the timing to zero anytime.
Swag says
use any small arbitrary value for C1, note the timing delay for this C1 practically and then divide 3 hours with this delay value.
make sure to convert 3 hours to seconds if the delay value was in seconds.
the answer will be your new C1
Godson Ugo says
Thank you very much for the response sir. I’ll do as you said. In the case of using a PNP transistor, how will the “time elapsed LED” be connected?
Swag says
connect the LED through a 1K resistor from positive to the pin of the IC associated with the BC557 base
andrea says
hi swagatam,
is possible obtain a opposte one-shot timer, in other words, when i press the button the load is swicth on for a preset time, elapsed this time, the load switch off and the timer remain in wait for next push.
thank you so much
Swagatam says
Hi andrea,
you can achieve it through the first two circuit shown in the following article
https://homemade-circuits.com/2012/05/simple-delay-timer-circuits-explained.html
or this
https://homemade-circuits.com/2014/11/long-duration-timer-circuit-using.html
or you can also use a IC555 monostable circuit design
Sriram Kp says
Thank u. waiting for the circuit…
Wong Trumph says
Vanakam Swagatam,
Just to confirm your statement,
1.The emitter(E) with arrow pointing inward is connected to relay that connects the positive supply.
2.remove Relay/Diode 1N4007 and put in after (C)ollector.
Erm, can you email me (june1629@yahoo.com) the diagram cos I might be wrong and position of diode cathode/anode. 🙂
Another thingy, why we cant comment as Anonymous? It is removed from dropdown. 🙁
Nandree
Swagatam says
Hi Nandree,
the arrow pointing inwards is the emitter is the emitter of the BC557, it must go to the positive line directly.
bring the relay along with its coil diode to the other side that in between the collector and the ground of the circuit
please refer to the following article and check the first circuit for getting a perfect idea regarding the discussed connections of BC557 with a relay
https://homemade-circuits.com/2013/02/how-to-drive-relay-through-opto-coupler.html
yes "anonymous" has been restricted by me, in order to control and stop spam comments
Anonymous says
Vanakam Swagatam,
The explanation above is wonderful.Again Im burning midnight candle reading. 🙂
However referring to the circuit with relay, I have a question.
1. When I push button, the relay is ON for a duration of the timer? How long is the duration?
In other words,
Im lookin for a circuit that say when power is ON, relay is also ON for an adjustable duration of say 30 mins or 1 hour. Can this circuit achieve that?
June1629
Swagatam says
Hi June,
you can achieve up to more than 10 hours of delay with reasonable accuracy with this IC.
P1 and C1 are the two components which directly determine the delay durations, increasing their values will increase the delay length and vice versa. the results will be very linear so it's just a matter of some trial and error until you are able to calibrate the P1 knob dial with the related delay magnitudes (numbers)
Anonymous says
Vanakam Swagatam,
Correct me if wrong, this circuit is designed to trigger the relay ON (power going into relay coil) when timer finish count down. How can I modify it such that the relay is ON when timer is counting. When timer is done, relay is off?
Swagatam says
you are corect june, in order to get an opposite response, you can try replacing the BC547 with a BC557 and connect its emitter to the positive supply while the relay/diode assembly across the collector/ground of the circuit, this will invert the response of the relay as per your preference
Boyet Raquel says
gud day can you please post an effective PWM for my HHO. 12v, 60 A.
thanks a lot in advance
Swagatam says
you can try the one given in the following link, the motor points may be used as the supply for the electrodes
https://homemade-circuits.com/2012/05/make-this-pwm-based-dc-motor-speed.html
jason bobis says
Sir.. Can you please design for me a circuit that counts down from 30 seconds to 0,that has a reset button which brings back the timer to 30. And also a pause button,this circuit will serve as a 30 second shot clock for amateur basketball. This is what I need for my school project.
Thank you sir in advance.
Hoping for your help.
Swagatam says
Hi Jason, I'll try to do it soon.
uel man says
sir i already emailed you the diagram.
Anonymous says
continuation… I am actually planning to use the 7th output of the one-shot decade counter to trigger an SCR to activate IC4060 for 2 minutes..
Anonymous says
hello sir, can you please help with my circuit. I'm utilizing 555 timer as the astable pulse to a monostable decade counter by on & off contact (normally Open ) of pin 8, 13 & 15 of IC4017. Now I want to use the 7th output of IC4017 to activate this contact to be OPEN or disconnected for 2 minutes using Relay. Can you please help me. I already have my 555 timer beating, and the IC4017 LED outputs glow sequentially once when pin 15,13 & 8 are connected momentarily (using relay). Pls. help. you can email me at lwn2012@yahoo.com Thanks
Swagatam says
Helo lwn2012
You will have to show me the diagram that you have constructed only then i would be able to provide an appropriate suggestion.