High Frequency Characteristics of Amorphous Tape Wound Cores used for Controlling a Switched-Mode Power Supply

This paper reports the high frequency characteristics of Co-rich amorphous tape wound cores under the flux resetting characteristics up to 2O0kHz. The characteristics can be utilized for magnetic amplifiers in a switched-mode power supply. The advantages of the amorphous cores have been clarified as compared with 50%Ni-Fe, 79%Ni-Fe and Mn-Zn ferrite cores. Some problems related to the stability and sensitivity of the amorphous cores are also discussed. Core noise and anomalously long transient response are the serious problems in the flux resetting characteristics. But these problems can be suppressed by increasing exciting frequency or by lowering the exciting impedance. It is found that amorphous cores are very suited for magnetic amplifiers operating at a high frequency range in a switched-mode power supply.