When I was working in the test dept of a transformer manufacturer we made some 3 phase 400 cycle transformers they were tiny even the 5 KVA ones were easy to pick up not lime the 50 cycle ones which weighed a ton not literally but still heavy
Yep,
This is why the switch-mode power supply has become so popular, the higher the frequency, the smaller the transformer you require.
I still have a pet hate of them things though, especially as far as things like RFI goes.
