Principles of Operation: Functionality

In a single generator system, with the key in the ON position, voltage is applied through the warning indicator I circuit to the voltage regulator. This turns the regulator on, allowing current to flow from the battery sense A circuit to the generator field coil. When the engine is started, the generator begins to generate alternating current (AC) which is internally converted to direct current (DC). This current is then supplied to the electrical system through the output terminal (B+) of the generator.

Once the generator begins generating current, a voltage signal is taken from the generator stator and fed back to the regulator S circuit 4 (WH/BK) (gasoline engine only). The stator circuit is external on gas engines and internal on diesel engines. This voltage feedback signal (typically half of the battery voltage) is used to turn off the charging system warning indicator on gasoline engines.

With the system functioning normally, the generator output current is determined by the voltage of the A circuit 35 (OG/LB). The A circuit 35 (OG/LB) voltage is compared to a set voltage internal to the regulator. The regulator controls the generator field current to maintain the correct generator output.

The set voltage varies with temperature and is typically higher in cold temperatures than in warm temperatures. This allows for better battery recharge in the winter and reduces the chance of overcharging in the summer.