Durango 2WD V8-5.7L Hybrid (2009)
Voltage Regulator: Description and Operation
Voltage Regulator - Operation
OPERATION
The amount of DC current produced by the generator is controlled by EVR circuitry contained within the PCM. This circuitry is connected in series with
the second rotor field terminal and the generator ground.
Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field. The EVR circuitry monitors system line voltage (B+).
It then determines a target charging voltage. If sensed battery voltage is 0.5 volts or lower than the target voltage, the PCM uses Pulse Width Modulation
(PWM) to ground the field winding until sensed battery voltage is 0.5 volts above target voltage. A circuit in the PCM cycles the ground side of the
generator field up to 100 times per second (100Hz), but has the capability to ground the field control wire 100% of the time (full field) to achieve the
target voltage. If the charging rate cannot be monitored (limp-in), a duty cycle of 25% is used by the PCM in order to have some generator output.
