Firing Board Failure - help please

Discussion in 'Weapons & Pneumatics' started by tgalx3, Apr 26, 2023.

  1. tgalx3

    tgalx3 Well-Known Member

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    I have installed polulu firing boards in my boat. The board that is controlling the stern gun has failed catastrophically twice now (sparks and small flames). The board that controls the bow gun works perfectly. Solenoid triggers as fast as I press the stick. Both boards are wired up the same.

    The only difference between the two boards is that the bow gun, which works properly, has a signal inverter on it and the stern gun does not.

    Side note, I have not cut any of the wires from the receiver and am using power from the main batteries to run the entire system. Not sure if that helps at all.

    IMG_0919.jpg
     
  2. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    Picture of underside and connectors?
    Did it catch fire when plugged in or when activated?
     
  3. Kotori87

    Kotori87 Well-Known Member

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    Is there a flyback diode, and is it installed correctly?
     
  4. tgalx3

    tgalx3 Well-Known Member

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    It caught fire only when triggered.
     
  5. tgalx3

    tgalx3 Well-Known Member

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    There is a flyback diode its at the solenoid. Its soldered on, I feel pretty confident that its in there correctly. But haven't tested with with a multi-meter.
     
  6. tgalx3

    tgalx3 Well-Known Member

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    IMG_0920.jpg IMG_0921.jpg
     
  7. tgalx3

    tgalx3 Well-Known Member

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    Uhhhhh. I did just notice (after looking at my own picture) that the silver band on the flashback diode is on the black side. The silver band is on the red side on the board that is working properly. Im not an electrical engineer, is that something that should be swapped....?
     
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  8. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    Silver band should be on the positive side. That is likely your issue.
     
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  9. Kotori87

    Kotori87 Well-Known Member

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    Yes. If the flyback diode is connected wrong, it will short-circuit whenever you try to trigger the solenoid. That draws too much current and damages the control board. I made that mistake once, and I got to watch electrical bits glow orange and combust.
     
  10. tgalx3

    tgalx3 Well-Known Member

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    Hey!!! Me too. Fireworks in April. I’ll swap it around. Thanks guys
     
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  11. tgalx3

    tgalx3 Well-Known Member

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    It works!!
     
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  12. GregMcFadden

    GregMcFadden Facilitator RCWC Staff

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    Uhhh... If you are using the medium MOSFET pololu switch there is already a diode on board for use with highly inductive loads, and another is not required.