Alternator: Description and Operation
OPERATIONwhen ignition switch is turned On, a small electrical current flows through the lamp filament (turning lamp on) and through the alternator regulator to the alternator field. When engine is started, the alternator field rotates and produces a voltage in the stator winding. When voltage at alternator stator terminal reaches about 3 volts, the regulator field relay closes. This puts the same voltage potential on both sides of the charge indicator lamp, causing it to go out. When the field relay has closed, current passes through the regulator A terminal and is metered to the alternator field.