cap discharge resistor

Discussion in 'Off-Topic' started by electronis whiz, Aug 4, 2011.

  1. electronis whiz

    Thread Starter Well-Known Member

    Jul 29, 2010
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    i have seen alot of 45 ohm 25 watt resitors would one of these be ok for discharging filter caps?
     
  2. #12

    Expert

    Nov 30, 2010
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    Ohm's Law: E = IR
    Watts Law: P = IE
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    I like to use appropriately rated incandescent light bulbs to discharge caps.

    You get a visual indication of the progress, and light bulbs have a rather unique non-linear resistance; it's high when the filament is glowing, and low when the filament is cool; the discharge rate actually increases as the lamp grows dim.
     
  4. debe

    Well-Known Member

    Sep 21, 2010
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    I agree with Sarge. For HV caps in SMPS ive been using a mains globe with insulated probes for discharging caps.
     
  5. #12

    Expert

    Nov 30, 2010
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    What's a "mains globe"?
     
  6. debe

    Well-Known Member

    Sep 21, 2010
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    In this country 240V in America 120V. Incandesant globe.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    The common name over in the States is "light bulb", although nowadays one has to qualify that with "incandescent" to differentiate the tungsten filament bulbs from CCFL's, LEDs, fluorescent lamps etc.
     
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