I need to make a voltage level decay slowly (approx 2 sec)when switched off, i need it to come on fast on start up, any circuit ideas or suggestion appreciated.

Kind regards
Paul

 

Adjust the resistor and capacitor to achieve the correct output voltage at 2 seconds after turn off.

 

Note that the resistor in your circuit may just be your load, and you just need to find a capacitor large enough to power your load for 2 seconds. Easy if you know how much it's drawing.

What are you trying to do?

 

Thanks #12 and wayneh just what I needed.


Paul

 

Is it the normal time constant formula T = R X C

 

No. It's complicated...Log natural and all that. Here's a web page calculator.

http://www.bowdenshobbycircuits.info/rc.htm