Across the line?

Discussion in 'The Projects Forum' started by inwo, Dec 27, 2013.

  1. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
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    What is good practice device to protect line input?

    Could be to a transformer or diode/thyrister circuit.

    I'm using a fusable link on the pcb in and out, and a line rated X1Y1 cap across the ac input.
    http://www.digikey.com/product-detail/en/DE2F3KH103MA3B/490-4217-ND/1021453

    It's in a noisy environment. Hand held drill.

    I'm thinking a mov might keep blowing fuse from the noise.
    Noise won't effect the rest of circuit.

    Maybe nothing is best?

    Also have a diode across diode/scr bridge. Corner to corner. Redundant?
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,509
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    Are you trying to prevent EMI etc getting back on the line or the internal electronics?
    Many of the industrial drives, use a R/L filter (Corcom) network system similar in design as used on the input to PC supplies etc, avail from Digikey.
    For internal DC supplies, a sufficiently large smoothing/de-coupling capacitor across the supply together with a .1μf across the electrolytic should be sufficient.
    Max.
     
  3. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
    2,433
    315
    Just trying to protect the diodes and scrs from destruction.

    Just seems like I should have something across the input.:confused:

    Space is limited.

    Maybe the .1 across the bridge instead?
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,509
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    Many of the bridge/SCR type drives just use a 150v MOV and a parallel .1μf cap across the bridge input and a small ferrite choke in series with the DC load, for the 120vac version.
    Max.
     
    inwo likes this.
  5. inwo

    Thread Starter Well-Known Member

    Nov 7, 2013
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    I'm not too far off with the .1 cap then.

    The diodes and scr are 600 volt.
     
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