Fine grained Mn-Zn ferrite for high frequency driving

A Mn-Zn ferrite with a grain size of about 2 mu m has been developed for th e transformer driven at around 1 MHz. The developed ferrite exhibits consid erably lower core losses than a conventional Mn-Zn ferrite with a grain siz e of about 10 mu m at a frequency of 0.5 to 2 MHz. The thin-type transforme r using the developed ferrite driven at 1 MHz shows a high efficiency of mo re than 95% at an output power of 10 to 17 W and a much lower surface tempe rature rise than the transformer using the conventional ferrite. (C) 1998 A merican Institute of Physics. [S0021-8979(98)42211-4].