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Transformer Current Drops with Load

  1. Feb 4, 2014 #1

    I have observed that as the load applied to a transformer secondary is increased (i.e. Increased Impedance), the current drawn by the transformer seems to decrease. Is this purely due to the fact that because the voltage remains fairly constant and the impedance is increased, the current must be reduced to allow ohms law to be maintained??

  2. jcsd
  3. Feb 4, 2014 #2


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    Power in the primary will be the same as power in the secondary. Wp = Ws
    Therefore Vp * Ip = Vs * Is
    Increasing the load impedance will reduce the secondary current according to Ohms Law.
    That in turn will reduce the primary current.

    “Increase the load”? Or “increase the load impedance” which would reduce the load?
  4. Feb 4, 2014 #3


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    A language problem here: The term "Increasing the load" involves increasing the Current, which implies Decreasing the Resistance (Impedance) of the Load.
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