Time delay circuit.

[ericgibbs]

A CD4060 oscillator/divider is only $.48US at Digikey.
A CD4541 is only $.55US.

They don't need a 5V regulator like old TTL needs.

Hi mazur,
IMO, this is the way to get the job done...... as AGU states.

 

[mazur50]

Hi mazur,
IMO, this is the way to get the job done...... as AGU states.

Do you have a Diagram for this.

 

[audioguru]

The 14th stage of the CD4060 has an output when 16,384 clock pulses have occured. Then for 60 minutes its oscillator must be 4.55Hz. The datasheet shows its pins and how to calculate two resistors and a capacitor for its oscillator.

The divider in the CD4541 can be set to divide its clock by 65,536. Then for 60 minutes its oscillator must be 18.2Hz. The datasheet shows its pins and how to calculate two resistors and a capacitor for its oscillator. It can be set to reset when power is turned on.

 

[ljcox]

I agree that this is a better way to do the timing.

However, if you read his original requirement, he wants to vary the delay from 0 to 60 minutes.

So the oscillator driving the CD4541 would have to be variable from 18.2 Hz to at least 18.2 * 120 = 2.2 kHz thus giving a delay from about 30 sec to 60 min.

Also, in a PM he told me that he wants the relay to be operated during the delay and release at the end. So the simplest way I can think of the do this is to halve the osc frequency (ie. make it 9.1 Hz to 1.1 kHz) and drive the relay from the last stage.

That is, the relay is operated while the counter output is low and releases when it goes high.