OPEN SWITCH WITH CAPACITOR+IC?,,

[namara]

HI,
im building a circuit for an LED clock display

i would like the display to turn off after a period of time automatically,
apart from using a time delay switch,
it seems like there is another way to do this using a capacitor and IC,
i.e the IC outputs a high when the capacitor reaches max.
what type of IC can sense the capacitor max.


THANKS FOR ANY HELP,

 

[Leighcusack]

What about capacitor and a transistor.
Crude but it'll work

 

[shrtrnd]

Yeah, or since the display will be off the next time you want to check the time, and
you have to activate the display anyway. Why not just put a momentary normally open switch in the display power circuit. Push the button and hold it to check the time, and then release the button, to turn the display off again.
(Unless I'm missing something in your description of what you want to do)