Voltage and current limiting phase-triggered battery charger with continuous optimization of charging rate

摘要

A battery charging circuit includes a silicon controlled rectifier full wave bridge that has its input connected across a conventional 60 hertz alternating current power line. The output of the bridge provides 120 hertz pulsating direct current to the battery being charged. The duration of each direct current charging pulse is determined by phase triggering of the silicon controlled rectifiers in the bridge. The silicon controlled rectifiers are triggered at a predetermined, identical firing angles by a conventional unijunction transistor relaxation oscillator which in turn is regulated by an output voltage and output current sensing circuit that established the noted firing angles so as to regulate, and limit at desirable upper valves, the charging voltage and current applied to the battery. The output sensing circuit includes as primary components a pair of adjustable zener diodes operating in their linear or active regions so as to function as amplifiers, one for output current regulation and the other for output voltage regulation.