Bleeder resistor questions

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  • Trinite
    Senior Member
    • Dec 2010
    • 143
    #1

    Bleeder resistor questions

    I have an audio device that is storing 107V in the capacitors, even when off. Do audio systems normally have bleeder resistors for these applications?

    If so, what values would I be looking at? I did some calculations and found that a 20kohm resistor will dissipate about 0.57W at full voltage. So would a 1W 20kohm resistor be ideal?
    Tags: None
    • Trinite
      Senior Member
      • Dec 2010
      • 143
      #2
      Re: Bleeder resistor questions

      Anyway, after thinking about it, 20kohm shouldn't have any effect on audio quality, plus, it is on the main power rail. But as it is a potential safety issue, I figure I should add one in.

      This is what I selected: http://search.digikey.com/scripts/Dk...e=P20KW-1BK-ND

        Comment

        • CWB
          Member
          • Jan 2011
          • 34
          #3
          Re: Bleeder resistor questions

          a bleeder resistor that is calculated to discharge (theoretically to zero) a cap in a power supply in (say) 15-20 seconds after main power is removed is about ballpark for average use .
          a bleeder that "consumes" 1% (or less) of the available power will have virtually no effect on the quality of the unit it is providing power for ...
          unless the design is marginal to start with and the supply has no head room under peak demand conditions .

            Comment

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