Dynamic behavior of magnetic amplifiers with nonresistive loads and feedbacks

The dynamic behavior of a magnetic amplifier with RC (resistance-capacitance) load or RC feedback is viewed here as a pulse-width modulated system. A linearization method is introduced whereby the average of the variable over a specific time, 1 half-cycle, is taken as the dependent variable of a finite difference equation. A modular differential equation is then derived whose solution coincides at the discrete instants of interest with the values of the variable of the difference equation. This makes it possible to employ transfer function techniques when a study of systems, involving the magnetic amplifier of another pulse-width modulating device, is attempted. Agreement between experiment and theory in a wide variety of instances illustrates the generality of the method.