Need help on Simple timer circuit

Discussion in 'The Projects Forum' started by swilson, Mar 31, 2012.

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  1. swilson

    Thread Starter New Member

    Mar 31, 2012
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    Need help with a circuit that should be simple please.

    Circuit 1 has 14VDC continuous. Circuit 2 has 14VDC continuous when a condition is met. When condition is fixed, if I open and close circuit 1, then circuit 2 is reset (no 14VDC) until condition is met again. Need 3 second timer to delay open of circuit 1 and then 3 second to delay close of circuit 1 so circuit 2 is reset. Circuit 2 will lose 14VDC as soon ans circuit 1 is open but need the 3 second until circuit 1 is closed again.

    Played with relays and 555 but can't figure how to keep power going through 555 for the 3 seconds until red/wh back closed using circuit 2 as power source and signal.

    If you can help out it would be greatly appreciated
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    1. The two 14VDC, are the from two different windings of a transformer or from the same bridge/filter circuit.

    2. There are two ways to go abt it to make the circuit simple.
    a, Component wise.
    b, Dummy wise. :D

    Which do u prefer ?
     
  3. swilson

    Thread Starter New Member

    Mar 31, 2012
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    1. They are on a truck. Circuit 1 is the PTO power...from a switch. Circuit 2 is on 87A of a relay thats normally not hot unless PTO is on and someone trips a condition that turns PTO off such as hitting the brake pedal. truck will not resume on its own after that, it needs manual cycle of switch which is annoying. When switch is on, under normal operating conditions, 87A gets 14V for 3 seconds then nothing (3 second timer in the circuit also) so maybe 5 seconds delay to open would work better. Hope you understand

    2. I would first choose most reliable I guess, then easiest, most cost affordable. Component and dummy solutions would be great. :)
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Read the Tos and post back.

    U will know what I mean.

    I can give u a easy or reliable or even dummy solutions.

    But must comply with forum rules.
     
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  5. swilson

    Thread Starter New Member

    Mar 31, 2012
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    Ah I see, sorry about that. I was going to edit my post but the edit button is gone. I guess I shoulda read the tos for once.
     
  6. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    U are new, u have to post more than I think 10 times to be able to edit it.

    Do u think ur topic complies with in the forum guidelines?
     
  7. swilson

    Thread Starter New Member

    Mar 31, 2012
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    Well, this is not really a automobile modification but more an enhancement on a machines (PTO's) circuit. I think my topic complies if you mean where I said help in the topic. I wasn't crying for help but just meant I need a hand.
     
  8. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Lesse what mod's comes up with.

    For the time being I can go on.

    What are u comfortable with?

    555 and gates with relays as such or μicro controller as in microchip's.

    First option circuit will be bigger and a bit costly but the Later is cheap and small
     
  9. Wendy

    Moderator

    Mar 24, 2008
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    The All About Circuits forum Administrative Team has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

    This thread is against the AAC forum rules, Chapter 6, as seen here:

    http://www.allaboutcircuits.com/l_tos.html


    Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

    Please try to understand the reasons behind this action, and feel free to browse and use the forums.

    You might find answers to your questions in one of these forums:

    http://forum.allaboutcircuits.com/sh...ad.php?t=54400

    A different forum I visit that does not have these rules is http://www.electro-tech-online.com/ ,
     
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