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Capacitor length/volume, does it matter?

Discussion in 'Repairing Electronics' started by halleffector, Sep 22, 2017.

  1. halleffector

    halleffector Member

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    I want to replace a broken capacitor in an ATX power supply for a desktop PC. The capacitor is 2200 uf, 10 V, so I find e.g. this one:

    http://www.ebay.com/itm/Free-Shippi...315952?hash=item2cba7d02f0:g:nccAAOSwRXRZQ0JF

    And I notice it looks like it is less than half the height of the original part.

    Does that matter? Can I safely use that capacitor as long as it is rated correctly capacitance and voltage, or do I need to look up other attributes as well?

    Why are some capacitors much bigger than others, yet rated similarly?
     
  2. crutschow

    crutschow Well-Known Member Most Helpful Member

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    Improved manufacturing processes may allow a reduction in capacitor volume for the same capacitance (assuming it's from a reputable manufacturer, which is an unknown for that ebay item).
    Those are probably okay for experimental purposes but I would buy a known brand for replacement in your power supply.
     
  3. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    I would strongly suggest you use a capacitor from a good manufacturer, I usually stick to Rubicon or Panasonic - and using low-ESR ones is a good idea.

    There's a LOT of cheap crap capacitors about, which is why they fail so much - and a PC is likely to be full of the cheapest ones they could find.
     
  4. dave

    Dave New Member

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  5. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Yes. You need a low ESR and a 105°C temperature rating.
     
  6. Chris Edwards

    Chris Edwards New Member

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    A capacitor of any size may be relatively high in capacitance and low in working voltage and vice versa. Small size capacitor implies a high dielectric constant and a high dielectric constant usually has some disadvantages in many cases.
     
  7. tomizett

    tomizett Active Member

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    I seem to remember something about tall thin caps being better at dissapating heat then short stumpy ones, but I can't rememberthe details...

    Rated ripple current (which I suppose is related to ESR) is another thing to considder, although you might not be lucky enough to find a datasheet for your original part.
     
  8. Mark G. Cooper Sr.

    Mark G. Cooper Sr. New Member

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    Nichicon also is a very high quality capacitor, I use them almost exclusively with very good results and long life.
    Best regards, Mark..
     

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