Need help with Momentary pulse when turning off 12v

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

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  1. gmdangelo

    Thread Starter New Member

    Oct 6, 2011
    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?

  2. bertus


    Apr 5, 2008

    I am closing this thread as it violates AAC policy and/or safety issues.

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