Some applications of semiconductor devices in the feedback loop of regulated metallic rectifiers

TREMENDOUS advances have been made in semiconductor technology during the past 5 years. One of the many fields to benefit from this progress has been power rectification. The extended-area, germanium-junction diode is now a reality. The possibility of using silicon instead of germanium to provide greater freedom from ambient temperature limitations is being investigated. These new rectifying elements have improved the size, weight, efficiency, and reliability of rectifier equipments. To keep pace with the rectifying elements, there is need for corresponding improvements in regulating circuitry. It is the author's belief that this challenge will be met by the wider application of semiconductor devices in regulating circuits. Low-level junction transistors and low-leakage junction diodes are now available. Junction transistors with higher power ratings and junction diodes suitable for use as voltage standards are being developed. It is the purpose of this paper to present a few basic circuits illustrating the use of these devices to perform various functions in the feedback loop of a regulated rectifier. The type of regulated rectifier chosen for example is one suitable for charging and floating telephone central office storage batteries. As a starting point, the essential functions in the feedback loop of such a rectifier will be considered.