Timing Circuit

Discussion in 'The Projects Forum' started by hiluxsurf, Jan 18, 2011.

  1. hiluxsurf

    Thread Starter New Member

    Jan 10, 2011
    2
    0
    I need some help here on a timing circuit, I tried following the attached diagram with some additional relays but for some reason I cannot get it to work.

    This is what I need:

    A timing circuit so when I push a momentary switch, I have a ground output for 3 seconds.

    Now to go into a little more detail. I have two 12v inputs to switch the relays. I have 1 wire that needs the 3 second ground. If I have 12v on BOTH inputs, I need a momentary push of the button (momentary ground from pushbutton) to start the 3 second ground output. If I do not have 12v on BOTH inputs, I need the wire to passthrough to another wire with no 3 second ground output.

    All these wires are low current signal wires.

    Any help would be highly appreciated!! Thanks!
     
  2. hiluxsurf

    Thread Starter New Member

    Jan 10, 2011
    2
    0
    As far as the application goes, I have an aftermarket alarm with push button start. The push button has two wires, a ground, and a return ground to the alarm brain. To turn the vehicle off I have to step on the brake and hold the button for 2 seconds. I'd like to get rid of the two second delay. So I figure I can install a timing module inline with those two wires. In order for the two second ground output to be activated, I need to have the 12v from both the brake signal and 12v from the tach signal. This would allow me to push the button once quickly, and have the circuit finish "holding down the button" for the remainder of the 2 seconds.
     
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