Magnum SRT-8 V8-6.1L VIN 3 (2006)
Voltage Regulator: Description and Operation
VOLTAGE REGULATOR
DESCRIPTION
The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.
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 generators second rotor field terminal and its ground.
Voltage is regulated within the PCM on the NGC vehicles, to control the strength of the rotor magnetic field. The EVR circuitry monitors system line
voltage at the PDC and calculated battery temperature or inlet air temperature sensor (refer to Inlet Air Temperature Sensor). It then determines a target
charging voltage. If sensed battery voltage is lower than the target voltage, the PCM feeds the field winding until sensed battery voltage is at the target
voltage. A circuit in the PCM cycles the feed side of the generator field at 250 times per second (250Hz), but has the capability to feed 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 20% is used by the
PCM in order to have some generator output. Also refer to Charging System Operation.
