Hi all,
I seem to recall from distant memory that it's possible to make a pulse det ector out of two of transistors and a few resistors, but I can't find the c ircuit anywhere. Searches keep throwing up stuff about astable multivibrato rs and nand gates and that's not what I'm looking for.
Just need to be able to detect a 1 second pulse of 5v on an otherwise 0v li ne. The pulse comes only after several days of inactivity and should turn a n LED on permanently. No reset required and any subsequent pulses must *not
- turn the LED off again, so it's operating like a bistable latch (if that' s the right term).
Can anyone assist?
Tia.