Power Integrations, Inc.
ENERGY TRANSFER ELEMENTS INCLUDING UNMAGNETIZED MAGNETIZABLE PARTICLES

Abstract:

A method for making an energy transfer element provides a magnetic core having a gap in a magnetic path, positions in the gap magnetizable material that produces an initial flux density, cures the suspension medium, and wraps one or more power windings around the magnetic path. When the magnetizable material is magnetized, a flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material comprises a mixture of a suspension medium that includes uncured epoxy and magnetizable particles. The magnetizable particles are capable of permanent magnetic properties when magnetized. The particles of magnetic material having magnetic permeability of at least 1000.mu..sub.o. The particles of magnetic material that have a magnetic permeability of at least 1000.mu..sub.o and the particles of magnetizable particles are uniformly distributed in the suspension medium.