Stability of Co-Based Amorphous Wound Cores Used for Controlling a Switched-Mode Power Supply and Their Optimum Conversion Frequency

Co-based amorphous wound cores for switching-power supply saturable reactors were prepared, and comparing them with permalloy cores, changes in their magnetic properties with time and optimum conversion frequencies were studied. The greatest changes in magnetic properties were recorded for a sample which was not heat-treated. Magnetic field-annealed samples had large initial core losses but were stable over time. Optimum frequency of a high-rectangularity sample was 100 kHz. It was concluded that the high-frequency properties of Co-base amorphous cores are superior to those of permalloy wound cores.