A theoretical and experimental study of the series-connected magnetic amplifier

The mathematical analysis of magnetic amplifiers is made difficult by the non-linear characteristic of the iron. By simplifying the problem (neglecting leakage reactance and assuming an ideal B/H characteristic) a solution can be obtained which shows that the steady-state and transient operation of an amplifier having one of the two basic circuits analysed, depend on only three dimensionless coefficients. This solution leads to simple semi-graphical methods of determining the steady-state current and flux waveforms, and the response to sudden changes in input; satisfactory agreement between experimental results and theory has been obtained. Improvements in core characteristics have led to a simplified method of designing amplifier windings, and by special circuits amplifier delays have been reduced in the ratio of about 10:1.