I have a normally open push-style switch which provides current to a LED. What sort of schematic would allow the LED stay on for 30 seconds after the switch was pressed momentarily? For clarity here's an example timeline:
Time | observation
----------------------------
0s | switch is closed
0s | LED turns on
1s | switch is released (open again)
30s | LED turns off
Time | observation
----------------------------
0s | switch is closed
0s | LED turns on
1s | switch is released (open again)
30s | LED turns off