Very odd looking capacitor.

Discussion in 'The Projects Forum' started by franzschluter, May 30, 2011.

  1. franzschluter

    Thread Starter Active Member

    Jun 1, 2009
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    Hi I just removed this from my board. It has 6 pins.. each pair has a shorted leg. I'm guessing its broken. The pcb where it mounts would not make sense if these pins where to be shorted. Here is the pic.

    Could anyone tell me the value of this capacitor and its type? I made pics from all possible angles.

    Best Regards

    [​IMG]

    For all angles of the capacitor:
    Album link: photobucket.com/weirdcap
     
  2. franzschluter

    Thread Starter Active Member

    Jun 1, 2009
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    Or maybe it isn't a capacitor?
     
  3. bertus

    Administrator

    Apr 5, 2008
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  4. franzschluter

    Thread Starter Active Member

    Jun 1, 2009
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    I guess it would make sense... Any idea what kind of transformer it is? I only measure resistance or short in pairs. There is no resistance across which made me think it was a shorted cap.
     
  5. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    From what did you take the part?
    What was the function of the board?

    Bertus
     
  6. franzschluter

    Thread Starter Active Member

    Jun 1, 2009
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    Function:
    It is a DC servo shunt motor driver board. 190VDC field/armature 4,7A 0,33A. Variable speed with tach and pot input.

    This part is located near two SCR. Goes to gate and some resistors near it. It is a bit weird for me to be transformer because I thought it was DC voltage.
     
  7. Adjuster

    Well-Known Member

    Dec 26, 2010
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    Gate drive pulse transformer, to isolate the gate drive circuit from the power circuit?

    If so, the winding resistances could be quite low. You might mistake them for short-circuits.
     
  8. #12

    Expert

    Nov 30, 2010
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    It only requires a pulse to start an SCR, and this is probably a pulse transformer.
     
  9. franzschluter

    Thread Starter Active Member

    Jun 1, 2009
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    So its like an isolating transformer? each pair have low resistance. but crosswise or diagonally there are is no resistance at all. How do I check a pulse transformer? (Without scope)
     
  10. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    If each of the three pairs has a low resistance, and all other measurements between pairs have infinite resistance, then the pulse transformer is likely OK.

    Ken
     
  11. KJ6EAD

    Senior Member

    Apr 30, 2011
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