Magnetic Amplifiers

[T3sl4co1l]

Good info / design resource:
http://www.tuks.nl/pdf/Reference_Material/Magnetic_Amplifiers/Platt%20-%20Magnetic%20Amplifiers%20Theory%20and%20Application%20-%201958.pdf

Practical note: although you can use most any core, "square" cores are best: special ferrites, permalloy, nanocrystalline...  You can find Vacuumschmeltze parts at Mouser, or a few Magnetics parts here, http://www.surplussales.com/Inductors/FerToro/FerToro-3.html e.g. 50B12-1D (a small permalloy type).  Not sure where to find square ferrite aside from looking them up between manufacturers and magnetics distributors.

The most common use today is the 3.3V post-regulator in ATX+ power supplies.  These are usually amorphous or nanocrystalline inside a plastic snap-together case.

I put together a 100W bias supply over the weekend,





(I actually etched the board *years* ago, but never built it up until recently.)

12V input, 71kHz 32V squarewave, bipolar, isolated.

So, I've been playing with this a bit.

Tim