• To assure Idling stability, controls the generator output voltage to the optimum amount according to the engine operation and electrical load conditions.
• The PCM determines the engine operation and electrical load conditions based on the input signals from each control part. It then uses this information to control the energization time of the generator field coils.
Determination method for target excitation current
• Calculates the target excitation current according to the generator target output amount and the generator rotation speed.
• The generator target output amount is calculated according to the target battery voltage and battery voltage.
• During deceleration fuel-cut, the PCM increases the generator output amount and stores electricity in the battery. In conditions other than deceleration, only the required amount of electricity is charged according to the battery status to lower the load on the generator.
Determination method for field coil excitation time
• The PCM increases or decreases the field coil excitation current by sending a duty signal to the power transistor built into the generator.
• The field coil energization current changes according to changes in the power transistor excitation time. This is accomplished by changing the duty signal duty ratio. For example, when the battery positive voltage drops, the duty ratio of the duty signal sent to the power transistor is larger, increasing the field coil excitation current.