Automatic regulation of metallic rectifiers by magnetic control

Regulated rectifiers have numerous applications in the Bell System and recent years have seen increased use of selenium cells as the rectifying elements in these units. In large power plants, regulation has been achieved using reference standards and electronic amplifiers in checkback circuits. In plants having less than 50 amperes d-c charging capacity, however, it has been possible to use magnetic amplifier techniques to secure ± 1 per cent regulation, with an additional advantage that periodically renewable circuit elements have been eliminated in the regulating circuit.