Description & Operation

DeVille models are equipped with Denso SC1 high amperage output generator. An auxiliary generator, Denso 638, is available on Limousine models. Generators include a delta stator, rectifier bridge, and rotor with slip rings and brushes. A built-in regulator incorporates fault detection circuitry. A conventional pulley and dual internal fans are used to cool slip ring end frame, rectifier bridge and regulator.

Denso SC1 generator operates with 4 wire connections and a ground path through mounting bracket. First wire connection is the BAT (output) terminal. This terminal must be connected to the battery during operation. Second wire connection is connected from generator terminal "L" (connector terminal "B") internal regulator light driver to Powertrain Control Module (PCM). This circuit monitors and controls generator operation. PCM controls indicator light function. Third wire connection is connected from generator terminal "F" (connector terminal "C") to PCM. PCM also monitors this circuit. Fourth wire is connected from generator terminal "S" (connector terminal "D") to an external voltage reading. If this circuit is interrupted, regulator will default to internal voltage reading for control.

Regulated voltage varies with temperature. System limits voltage by controlling rotor field current while field current is on. Regulator switches rotor field current on and off at a fixed frequency of 400 cycles per second to help control radio noise. By varying overall on/off time, correct average field current for proper system voltage control is obtained. At high speeds, with lower electrical loads, on-time may be 10 percent. At low speeds, with higher electrical loads, on-time may be as much as 90 percent. See GENERATOR SPECIFICATIONS  .

Denso 638 generator functions as a secondary generator in a dual generator system with Denso SC1 generator as the primary generator. Denso 638 is smaller, and is used to maintain battery voltage over an extended idle period with high loads. Denso 638 functions are same as other generators, but is not PCM controlled. When engine is running, power is sent to battery positive voltage sense circuit, turning on regulator. Regulator uses input voltage to control output of generator.