Power losses of soft magnetic ferrite under controlled magnetizing condition

Power losses of a soft magnetic ferrite were measured under several controlled magnetizing conditions, in which the magnetic induced voltage was strictly controlled to be required waveforms; sine, rectangle and rectangle with steps. Different power losses in one magnetizing cycle are obtained even under the magnetizing conditions in which the same eddy current and hysteresis losses are expected. Power losses under sinusoidal excitations are higher than those under rectangular voltage excitations. It is considered that the hysteresis losses, which are generally believed to be constant and independent of magnetizing frequency, should depend on the magnetizing waveform, that is, the change of the magnetizing speed.