Need help with Momentary latch when turning off 12v signal

Discussion in 'The Projects Forum' started by gmdangelo, Oct 6, 2011.

Thread Status:
Not open for further replies.
  1. gmdangelo

    Thread Starter New Member

    Oct 6, 2011
    2
    0
    I need help designing a circuit that will latch a relay for about 0.5 sec when I remove a 12v signal line. The other requirement is that it only latches when I remove the 12v and not when I apply it. I was hoping to do it with relays, capacitors and resistors since I have all these parts already. Can anyone offer some help?

    Thanks
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    This question closely resembles your earlier one -
    [​IMG] Need help with Momentary pulse when turning off 12v
    I need help designing a circuit that will latch a relay for about 0.5 sec when I remove the 12v power and only when I remove the 12v and not when I apply it. This is going in a car application. What I’m trying to do is when I turn off my ignition I’d like a relay to close for about 0.5 sec. I designed one circuit that works but it draws a little bit of current when the car would be off and parked and that would be no good. I was hoping to do it with relays, capacitors and resistors since I have all these parts already. Can anyone offer some help?

    Thanks

    We can't help with this one either.
     
  3. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    The Terms of Service still apply to every message you write. Since we are now in position the goal of this circuit (forum.allaboutcircuits.com/showthread.php?t=60328), we are in position to deny any aid in building automotive modifications.
     
Loading...
Thread Status:
Not open for further replies.