I have a timing circuit that I need to start with a NO momentary switch connectedt to +5v and have that connection stay "on" until the circuit counts down to a preset time. At that moment the circuit sends a +5V signal out which I want to use to stop the circuit. Any ideas?

 

What is the time range you need? mSec? Seconds? Hours? Will you be changing the time?

Ken

 

How is that time going to be measured? A circuit diagram with your idea would be helpful.