Snubber component types for a triac-controlled dimmer

Discussion in 'General Electronics Chat' started by electrophile, May 31, 2016.

  1. electrophile

    Thread Starter Member

    Aug 30, 2013
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    What kind of capacitors and resistors would be used for a snubber in a triac controlled dimmer that would typically control say ceiling fans. For the resistor would a 1W carbon composition be sufficient? Also the local hardware store recommended these two types of capacitors. One of them has an AC voltage rating (275V) while the other has a DC voltage rating (630V). Which of these would be appropriate? (images attached).
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    The cap should be an X2 rated one (which the one in the first pic is).
    Without knowing the dimmer spec/characteristics I can't comment on the resistor, except to say that it needs to be rated for the mains voltage you have.
     
  3. takao21203

    Distinguished Member

    Apr 28, 2012
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    Dont use the DC capacitor by all means.
    The x2 parts are approved for mains connection.

    0.1uF is for very small watts, 220nf or 0.47 is better for a dimmer.
     
  4. electrophile

    Thread Starter Member

    Aug 30, 2013
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    @takao21203 Thanks! That helps.

    @Alec_t The dimmer is supposed to dim/speed control incandescent lamps and ceiling fans working with AC mains voltage. The lamps are rated for not more than 100W and the ceiling fan no more than 75W.
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    What is the resistance of the resistor?
     
  6. electrophile

    Thread Starter Member

    Aug 30, 2013
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    100R
     
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    A 1W 100R resistor will be fine.
     
  8. electrophile

    Thread Starter Member

    Aug 30, 2013
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