Core noise and an anomalous phenomenon in amorphous tape wound cores used for sensitive magnetic amplifier

This paper reports the core noise and an anomalous phenomenon related to the sensitivity of amorphous tape wound cores operating in a magnetic amplifier. Influence of material selection and of exciting parameters, such as drive frequency and control circuit resistance, are emphasized to realize a sensitive amplifier. The application circuits making use of these facts exhibited sensitive operation. Among the applications, the current surge suppression in a switched-mode power supply with high frequency switching is examined in detail.