Fuse on USB

Discussion in 'General Electronics Chat' started by beeson76, Jun 23, 2012.

  1. beeson76

    Thread Starter Member

    Apr 19, 2010
    I have a media card reader in my computer. It's brand new so I don't want to really throw it away. But anyway, to make a long story short, one of the fuses is blown on the USB part of the circuit. Would anyone know what fuse would I need to get. I'm more or less asking, the mA and voltage part because I'm going to replace it with a through hole fuse if I can get one with the right ratings. It is surface mount so its impossible to tell what it is. Thanks for any help provided.
  2. hexreader

    Active Member

    Apr 16, 2011
    Warning: I am no expert, so I may be talking rubbish, but....

    USB current output (from computer) is typically 500mA maximum, though not all USB ports can supply the full 500mA. (some devices can supply more than 500mA)

    So the safe answer would be to fit a 500mA fuse (fast blow).

    A card reader is unlikely to want much current, so my answer is still 500mA.

    Other devices, I might be tempted to fit 1A, as modern computers often have a "resettable" fuse internally, that can handle shorts. This might be a little risky, however.
    Last edited: Jun 23, 2012