Timer circuit mayhem!

Discussion in 'The Projects Forum' started by nmracer, Sep 11, 2011.

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  1. nmracer

    Thread Starter New Member

    Sep 11, 2011
    I am attempting to create a very basic circuit to automatically control the fuel system changeover on a vehicle. Essentially, I am trying to start two timers once the ignition is shut off in order to delay the actual engine shut off. In other words, once ignition is off pump 1 runs for another 2 seconds and pump 3 runs for an additional 60 seconds.

    Currently I am attempting to hook up two 555 timers but I am not sure if I am understanding the theory correctly. My idea was to hook up the ignition to pin 6 in order to start the timer once voltage was removed and have the output turn on a relay to the appropriate pump for the duration. However, it has come to my attention that the input signal needs to be shorter duration than the output? Does this mean I am unable to use a 555 for this project?
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
    See Bill Marsdens blog on 555 timers.
  3. magnet18

    Senior Member

    Dec 22, 2010
    sorry, but car mods are off-limits here for legal reasons
  4. bertus


    Apr 5, 2008

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

    6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

    • Any kind of over-unity devices and systems
    • Automotive modifications
    • Devices designed to electrocute or shock another person
    • LEDs to mains
    • Phone jammers
    • Rail guns and high-energy projectile devices
    • Transformer-less power supplies
    This comes from our Tos:
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    There will be enough sites where automotive questions can be discussed :
    Member selected automotive forums

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