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Help required please

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Csteve2409, Aug 12, 2018 at 4:53 AM.

  1. Csteve2409

    Csteve2409 New Member

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    Hi to everyone.

    I wonder if anyone can help me with what must be a simple answer but can't find any reference or real help on the web?

    I'm looking to build an American Don't Walk / Walk pedestrian crossing light. I am looking for the Dont Walk sign to light up for ten seconds and then change to the walk sign for ten seconds. That's about it but I can't find any reference to building a circuit that has this amount of delay time between the alternating led lights. I brought the build it yourself alternating kit but the max amount time each lights up is only about 5 seconds. I'm not the best soldering so any advice on how I can do this would be greatly appreciated.

    Many thanks.
     
  2. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Welcome to ETO!
    Can you post a schematic of the circuit you used?
     
  3. Csteve2409

    Csteve2409 New Member

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    Hello, many thanks for your reply.

    This is the copy of the details you get with the Vellemans kit.

    Many thanks.
     

    Attached Files:

  4. dave miyares

    Dave New Member

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  5. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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  6. alec_t

    alec_t Well-Known Member Most Helpful Member

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    The Velleman's circuit is not ideal for long time delays, but you could try either :
    1) replacing R3 and R4 with 270kΩ resistors, or
    2) replacing C1 and C2 with 33uF electrolytic capacitors.
     
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  7. Csteve2409

    Csteve2409 New Member

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    Thank you so much.

    It does not have to be exactly 10 seconds, just around that sort of time delay between each LED lighting. In fact it could be longer. I had looked at a 555 chip (is that correct?) but truthfully I'm a bit lost when it comes to these things.
     

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