Evaluation and selection of forward rectifiers for mag amp secondary post regulators

The selection of forward rectifiers for a magnetic amplifier used in post secondary voltage regulation plays a key role in the effective control of the saturable reactor switches. The author examines four types of rectifiers which could be employed in a design and discusses the limiting factors for each type. The rectifiers evaluated are the ultra-fast, fast, Schottky, and power MOSFET synchronous switch rectifiers. It is shown that devices with the lowest forward or reverse capacitance minimise the reset interval disturbance. Diode capacitance is shown to be an important parameter in the design of magamp regulators that employ cores for which the loop is highly square