High-temperature, high-frequency characterization system for power ferrites

An automatic magnetic test system is presented that can measure hysteresis loops of Manganese-Zinc (MnZn) power ferrites up to their Curie temperatures, in the 10 kHz-1 MHz frequency range. Low-cost test fixtures are constructed that can withstand elevated temperatures as high as 250 (degree)C. The experimental procedures for the automated acquisition of dynamic hysteresis loops with constant and with variable peak flux density are presented. The usefulness of the test system is demonstrated by the experimental results from three commercial MnZn power ferrites.