Not all millihenries are equal

If a perfect magnetic material existed, then transformer design would be extremely easy. This material would have no saturation effects, no losses and a permeability adjustable to user requirements from 1 to infinity. This perfect material has not yet been found, and the different types of magnetic core material all offer a compromise of one type or another. Variations with saturation mean that any comparison between magnetic components made using different core types has to be very carefully made. A millihenry measured under bridge conditions might well act as just a few microhenries under circuit drive conditions. The author gives a brief overview of the various types of core material in common use, and tries to show how their basic magnetic properties affect their suitability for transformers and inductors used in power electronics