Electronic Engine Controls: Generator
The Generator has a power control module voltage regulator for use in a 14V charging system with 6÷12 zener diode bridge rectifiers.
The engine control module (ECM) monitors the load on the electrical system via pulse width modulation (PWM) signal and adjusts the generator output to match the required load. The engine control module (ECM) also monitors the battery temperature to determine the generator regulator set point. This characteristic is necessary to protect the battery; at low temperatures battery charge acceptance is very poor so the voltage needs to be high to maximize any rechargeability, but at high temperatures the charge voltage must be restricted to prevent excessive gassing of the battery with consequent water loss.
The Generator has a smart charge capability that will reduce the electrical load on the generator reducing torque requirements, this is implemented to utilize the engine torque for other purposes. This is achieved by monitoring three signals to the engine control module (ECM):
- Generator sense (A sense), measures the battery voltage at the central junction box (CJB).
- Generator communication (Alt Com) communicates desired Generator voltage set point from engine control module (ECM) to Generator.
- Generator monitor (Alt Mon) communicates the extent of Generator current draw to engine control module (ECM). This signal also transmits faults to the engine control module (ECM) which will then sends a message to the instrument cluster on the controller area network (CAN) bus to illuminate the charge warning lamp. Refer to Generator .