REGULATOR FOR CHARGING A BATTERY WITH A PERMANENT MAGNET ALTERNATOR

摘要

OF THE DISCLOSURE A battery to be charged is connected to the stator winding output terminals of a permanent magnet alternator by way of two half-wave rectifier circuits. Each rectifier circuit has at least one controlled rectifier in series with the battery. The controlled rectifiers have gate terminals, respectively, for supplying a signal that renders them conductive. A semiconductor isolating or shut off switch, preferably a transistor switch, connects the battery terminal to a voltage divider circuit that develops two discrete voltage levels that are proportional to battery voltage. A zener diode circuit fed from the battery provides a stable reference voltage. A first comparator compares one of the voltages that corresponds with the battery voltage being a predetermined amount below full-charge condition with the zener reference voltage and if the reference voltage is exceeded, the comparator trips to turn on one of the SCR diode rectifiers for charging the battery at a relatively low rate with half-wave rectified dc. A second comparator compares a still lower voltage in the divider with the zener reference voltage and trips to effect turning on the other SCR diode to charge the battery additionally to the other SCR and the half-wave rectifier circuit in which it is connected. Thus, full wave charging occurs. If the battery is accidentally disconnected high voltage could develop on the alternator terminals. Disconnection turns off the isolating transistor and the controlled rectifiers lose their gating signals and turn off. High voltage across the alternator during the last half of the cycle before turn off is dissipated to ground by a zener diode.