Pulse-position-modulated vehicular alternator voltage regulator with dual AC-feedback networks, controlled 'OFF' period and low inserted electrical noise

摘要

A Frequency-On-Demand type voltage regulator firstly has its power output circuit configured as a resettable monostable multivibrator that provides (1) a stable time-base that serves as an internal “OFF”-period reference; preferably also with (2) short-circuit protection to the output power transistor; and (3) a pulse train with sharply defined “ON” and “OFF” transitions as the result of the interaction between the Output and Input Stages of the Power Output Circuit through a first AC Feedback Network. The “ON” and “OFF” transitions are preferably rounded-off. Secondly, yet another, second, AC feedback network is added between the Output Stage of the Power Output Circuit and the Error-Detector/Voltage Divider Stage of the Frequency-On-Demand type voltage regulator. This second feedback network provides (1) a controlled “OFF”-period synchronized with the Output Stage signal; (2) protection against loss of a reference voltage; (3) a dead band” associated with the “ON” and “OFF” periods that confers exceptional tolerance to system electrical noise; and (4) a voltage compensation feature with “flat”, “drooping” or “rising” system voltage output characteristic versus system loading.