Alteration of the dynamic response of magnetic amplifiers by feedback

THE purpose of this paper is to explain and illustrate the use of feedback techniques in the alteration of the dynamic response of full-wave magnetic amplifiers with d-c outputs. A generalized sinusoidal transfer function for a single-stage magnetic amplifier with feedback through frequency sensitive elements is derived, and several examples are given of the application of the feedback method in servo systems. Feedback, as discussed in this paper, is external and is applied to a basic amplifier in such a manner as to change its frequency response characteristics. The self-saturating amplifier, in particular, is considered to be a basic amplifier to which negative or positive feedback may be applied, although the analysis is also valid for other types of magnetic amplifiers.