Simple Adjustable Industrial Timer Circuit

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:

Vasilis Karastergios

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.