Autotransformer Vs Centre Tap Transformer

Discussion in 'General Electronics Chat' started by vks_foe, Apr 27, 2012.

  1. vks_foe

    Thread Starter Well-Known Member

    Jan 11, 2009
    What are the differences between the two?? in theory and practically too..
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    An auto transformer has no secondary windings. The "primary" is thus connected to the output on one set of connected wires.

    If you have turns of N1 between A and B, and turns of N2 between B and C (noting point "B" connects to both windings), you could apply a voltage between A & B and get another voltage between B and C of:

    V(B-C) = N2/N1 * V(A-B)

    (A picture would help here if anyone knows of a reference).

    A center tap transformer has 3 windings, primary and 2 secondaries. The secondaries are connected resulting in the end points being equal in voltage but opposite in phase.

    Again, a picture would help.
  3. debjit625

    Well-Known Member

    Apr 17, 2010

    Isolation, in case of centre tapped transformer you have two sides primary and secondary which are electrically isolated from each other and in case of auto transformer their is no electrical isolation. If you connect electrically primary and secondary of an isolated transformer it becomes an auto transformer.

    In real life many auto transformer comes with two separate windings primary and secondary, as per requirement we connect them to make the auto transformer.

    Good Luck