-- "Too much", actually. The transformer in my Tek 475 has quite thin
laminations. It's rated for 50-400Hz, of course. Eddy current losses go up
with frequency.
Eddy current losses are proportional to square of frequency and square
of magnetic flux. (At frequencies low enough for this to not get
complicated much by skin effect, stray inductances, whatever)
However, volts per turn is proportionate with magnetic flux and
frequency. That means eddy current loss is proportional to square of
volts per turn, unaffected by frequency.
Hysteresis losses are actually improved by using a higher frequency.
Those are *roughly* proportionate with square of magnetic flux but only
linear with frequency - so with constant volts per turn, this loss is
roughly inverse proportional to frequency.
(Hysteresis losses have messy nonlinearities, and the above is an
oversimplification.)
The usual problem with operating 50/60 Hz iron core transformers at 400
Hz is that leakage inductance in the transformer sometimes causes output
voltage to be less (with load) at 400 Hz.
- Don Klipstein (
[email protected])