Ferritkern-leistungsübertrager für schaltnetzteile

Abstract

Switched-power packs have become fairly well-established as the power supply of electronic instruments. They feature a medium-frequency power transformer which is one order of magnitude smaller than the corresponding system transformer of a conventional power pack. These transformers are succesfully equipped with ferrite cores. The interdependences of ferrite properties, construction, size, and transferable power of the transformer are discussed. The induction of the ferrite is limited by either saturation or losses of the core material to an admissible or optimal value. In the process, the core and copper losses become dependent on thermal resistance and permissible temperature rise. Optimal inductions, thermal resistances, and at different operation modes, transferable powers are given for power transducers equipped with special core types. Interfering leakage inductances can be kept to a minimum by interspersing tightly coupled wiring. The wires can be interspersed economically within one layer by using pre-manufactured flat cables.