Principles of Operation

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.

Positive Battery Output (B+) Circuit 38 (BK/OG)
The generator output is supplied through the battery positive output (B+) terminal on the rear of the generator to the battery and electrical system.

I Circuit 904 (LG/RD) - Single Generator
The I (ignition) circuit is used to turn on the voltage regulator. This circuit is powered up when the key is in the ON position. Voltage is supplied from the ignition switch to the central junction box (CJB) fuse 45 (10A), then to the instrument cluster and through the charging system warning indicator (battery icon) to the generator. This circuit is also used to turn the charging system warning indicator on if there is a fault in the charging system operation.

A Circuit 35 (OG/LB)
The A (battery sense) circuit 35 (OG/LB) is used to sense the battery voltage. This voltage is used by the regulator to determine the generator output. This circuit is used to supply current to the generator field (rotor). The amount of current supplied to the rotor determines the generator output.

S Circuit 4 (WH/BK)
The S (stator) circuit 4 (WH/BK) is used to feed back a voltage signal from the generator to the regulator. This voltage is used by the regulator to turn off the charging system warning indicator. The S circuit is fed back externally on gasoline engines and internally on diesel engines.