Alternator: Description and Operation

The generator provides voltage to operate the vehicles electrical system and to charge the vehicles battery. A magnetic field is created when current flows through rotor. This field rotates as rotor is driven by engine, creating an AC voltage in stator windings. The AC voltage is converted to DC voltage by the rectifier bridge and is supplied to the electrical system at the battery terminal.

The operation of the charging system is monitored by the PCM. The PCM monitors the charging system loads and adjusts the idle speed accordingly. The PCM also sends information to the Instrument Panel Cluster (IPC) when the charging system is inoperative and tells the IPC to illuminate the charge telltale.

The PCM supplies 5 volts through L circuit to generator. If generator becomes inoperative, PCM can detect fault through L circuit and tell IPC to illuminate charge telltale.

The PCM monitors duty cycle of generator through F circuit. As generator load increases, PCM will adjust idle speed accordingly.