estimate transformer losses with frequency

Discussion in 'General Electronics Chat' started by ariemeir, Apr 8, 2013.

  1. ariemeir

    Thread Starter Member

    Jun 24, 2011
    Hi all,

    My question is somewhat fundamental:

    If i take a regular step down transformer, say 120VAC on the input, 12VAC, 1A at the output, designed for 50/60 hz and i feed it a 5v p2p signal from a voltage generator into the secondary winding and i am getting 50v 2p2 at the primary around 50hz-1000hz region.

    However, I've noticed that as i go higher in frequencies, the voltage at the output increases.

    My question is: how can i roughly estimate the power loss as a function of frequency ?

    (My motivation behind this type of tinkering is building a low cost, variable frequency high voltage AC signal, so i want to know how much power will i be able to produce at the output, I intend to use a salvaged microwave transformer fed from an audio amplifier which is fed from a signal generator ).

    If you have any reservations regarding this type of configuration, I would appreciate your feedback.

  2. Brownout

    Well-Known Member

    Jan 10, 2012
    Power loss will be a product of inter winding capacitance, wire resistance and core loss. If you had all of this information, you could calculate the loss at your frequency of interest. I imagine loss would be significant, and heating could be an issue. If I were to try to build a high frequency high voltage signal, I wound't waste any time fooling around with a MOT.
  3. ariemeir

    Thread Starter Member

    Jun 24, 2011
    Thank you Brownout !