shorted transforfmer?

Discussion in 'General Electronics Chat' started by electronis whiz, Jul 29, 2011.

  1. electronis whiz

    Thread Starter Well-Known Member

    Jul 29, 2010
    i have an old transformer not sure what from apears to be a power transformer one winding only has .5 ohm resistance the other has 426 ohm. is the .5 ohm shorted?
  2. MrChips


    Oct 2, 2009
    The resistance measurements cannot tell you much about a transformer. What is important is the turns ratio, that is, how many turns are on the primary winding versus how many turns on the secondary winding.

    One can only guess that the winding with the very low resistance is the secondary and the high resistance is the primary assuming that this is a step-down transformer, going from a high AC voltage on the primary and a low AC voltage on the secondary.

    Another thing, you can get an idea of the power handling capacity by the physical size of the transformer and also by the size of the wire used on the two windings. I would guess that the wire size on your secondary is fairly substantial, 22 to 24 AWG maybe?
    Last edited: Jul 29, 2011
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