MAGNETIC-AMPLIFIER ANALYSIS USING A GENERALIZED MODEL FOR THE SATURABLE REACTOR CORE by HERBERT

A mathematical representation for a polycrystalline, thin-tape, ferromagnetic metal is derived for the operating conditions found during flux resetting in a magnetic amplifier. The starting point for the derivation is the dynamic behavior of the magnetization process in ferromagnetic single crystals reported in the literature. The general reactor representation is simplified to a form which is suitable for magnetic-amplifier analysis, and the simplified representation is verified experimentally. The constants which describe the reactor characteristics are obtained from a constant current switching characteristic of the type used for describing reactors in the digital-computer field. The simplified reactor representation is applied to the analysis of a single-core, self-saturating magnetic-amplifier circuit with a direct resetting voltage and arbitrary reset circuit resistance. The results of the analysis yield reasonably accurate predictions of the amplifier input-output characteristic over wide ranges of supply frequency and reset circuit resistance. In addition, the reset circuit parameters necessary for maximum power gain are obtained in terms of the reactor constants and supply frequency. At the same time, the analysis yields a measure of the relative reset circuit resistance necessary for operation with so-called current control and voltage control. This provides an answer to the problem of whether reset aircuit resistance is high or low. Thesis Supervisor: David C. White Title: Associate Professor of Electrical Engineering