Need help with simple adjustable delay circuit. 555

[HRD]

I would appreciate any help with this simple project. I have some basic electronics knowledge and experience, but far from an Electrical Engineer. Basically I have an input that is initially high (13-14v) and then goes low (~0v) and stays low. I want the output to initially be low or open then go high at some time after the input goes low. I need the time to be adjustable from 30 sec to 5 min.

I was looking at delay circuits using 555 timers, but they seem to all be geared toward a shorter time delay.

TIA.

 

[KeepItSimpleStupid]

I think this will work for you: https://www.electro-tech-online.com/custompdfs/2012/06/k141.pdf

You are correct, in order to get long time delays you have to count or use a microprocessor. Electrolytic caps have poor tolerances and leakages that they are not suitable.

 

[ClydeCrashKop]

Here is a 555 timer calculator http://www.csgnetwork.com/ne555timer2calc.html .
I think there are better ones.

 

[colin55]

Here is the circuit you need:

View attachment 65046

 

[alec_t]

Colin's circuit should work if (a) you're not too concerned about the accuracy and long-term stability of the time period, (b) the input voltage can never exceed the circuit power supply voltage, (c) the 40106 is a CD40106, and (d) the supply voltage is < 15V (the rated max working voltage of a CD40106).

 

[HRD]

Thanks for all the help. I was able to get a 555 circuit to do what I needed, but I am interested in Collin's CD40106 circuit. I'm about to show my ignorance, but what what is that component to the right of the diode?

 

[KeepItSimpleStupid]

That is a SPST relay or more specifically, the rectangle is the relay coil and the parts to the right are the Normally Open (NO) contacts.
The diode is necessary to absorb the spike from the coil when it is turned off.