transformer/ IM

Discussion in 'General Electronics Chat' started by eagle55, Mar 23, 2010.

  1. eagle55

    Thread Starter New Member

    Mar 9, 2010
    we know, transformer is sort of static induction motor. in no-load condition starting a power transformer draw 7-times more current like IM?:confused:
  2. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    The only time an unloaded transformer takes excess power is if the supply is turned on part way through the mains cycle.

    If the power is applied from the start of the cycle (as the voltage passes through zero) there is no surge.
  3. The Electrician

    AAC Fanatic!

    Oct 9, 2007
    You've got it just exactly wrong. The maximum transient (surge) occurs when you apply the voltage as the sine wave is passing through zero. No surge occurs when the voltage is applied at the peak of the sine wave (assuming the transformer inductance has no resistive component; otherwise the timing for minimum surge is slightly off of the peak).