Magnetic Amplifiers of the Balance Detector Type---Their Basic Principles, Characteristics, and Applications

At first two special problems concerning magnetic amplifiers for self-balancing d-c potentiometers and d-c bridge networks are specified. Numerous basic circuits of simple magnetic amplifiers preferably utilizing feedback effects are classified and explained. Then different push-pull circuits of the balance detector type are described systematically. Some figures for single-stage and multistage amplifiers are quoted to indicate the performance obtained. Speed of response in magnetic amplifiers, the possibility of providing derivative feedback, and design procedure with respect to time lag are briefly considered.