The research of the high initial permeability (6000 ~ 20000) ferrite and the frequency dependence of inductance of the ferrite transformer made by high permeability ferrite core are presented.

Also important is the minimum frequency that full power is possible - this indicates the amount of primary inductance and the quantity and quality of the core material.

Based on the design of the core inductance of the power filter, this paper presents analysis on the characteristics of the amorphous core and the microcrystalline core.