Needing a 555 12v LIGHT activated circuit and a DARK activated circuit

Discussion in 'The Projects Forum' started by itchey, Dec 27, 2014.

  1. itchey

    Thread Starter New Member

    Dec 26, 2014
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    Looking for a relatively simple circuit probably needing a 555 12v LIGHT activated circuit and a DARK activated circuit using a photo transistor to activate a relay for 1 to 30 seconds . Shut OFF and be re triggered again with in a minute or so. Thanks for any HELP you can give ITCHEY
     
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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  3. itchey

    Thread Starter New Member

    Dec 26, 2014
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    First off thank you for Replying. I am totally new at this. The issue is that once the circuit is triggered it stays on. I want to have the circuit ( or Relay)be ON for 1 to 30 seconds (controlled by me ) then turn off and be re triggered even though the LIGHT source or Darkness is still there . I hope that makes sense. Thanks Again For your response ITCHEY.
     
  4. #12

    Expert

    Nov 30, 2010
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    Keep talking. We need you to be more specific.

    A 555 chip can have power applied and wait for the light (or dark) detector to start its timing cycle. When it is done, it will typically re-trigger immediately because the amount of light available is still the same as when it was triggered 30 seconds ago. Do you want it to lock out for a minute after the first 30 seconds so it can not be re-triggered immediately?

    The basic shape of the circuit includes the light detector and the timing parts to make it persist in the "on" state. Please elaborate about your desires.
     
  5. itchey

    Thread Starter New Member

    Dec 26, 2014
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    I will try to be as specific as possible. When a light source is turned on, it will illuminate the photo transistor that in turn will activate a 12v 5a board relay, which will activate for ONE SECOND then turn off, yet be able to be re triggered all over again. Using the same light source with a seperate photo transistor WHEN THE LIGHT GOES OUT activate a second 12v 5a relay for ONE SECOND and then shut down and be able to be re triggered as well. This can be 2 seperate boards. It does not have to be just one board. It can be 2 different boards as there are 2 relays and 2 photo transistors. I hope this is as specific as you requested. Thank you for any help you might be ITCHEY
     
  6. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    Let's say that the light goes on, the circuit operates the relay for one second, but the light is still on. Do you want the timer to wait until the light goes out and then comes back on before the relay is operated again? Same question for the light going out.
     
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  7. #12

    Expert

    Nov 30, 2010
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    The obvious method will require a 556 chip, each.
    Still working on the details, as per tracecom.
     
  8. itchey

    Thread Starter New Member

    Dec 26, 2014
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    Yes thats what I am Looking for
     
  9. #12

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    Nov 30, 2010
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    Last edited: Dec 28, 2014
  10. itchey

    Thread Starter New Member

    Dec 26, 2014
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    Not a problem I have the metal pot Photo Transistors. The circuits need to be as simple as possible. I have a small local electronics store I will need to consult with to put these circuits together properly. again thanks again ITCHEY
     
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