Principles of Operation

Principles of Operation


Diesel Engines

With the key in the ON position, voltage is applied through the warning indicator I circuit to the voltage regulator. This turns the regulator on, allowing current to flow from battery sense A circuit to the generator field coil. When the engine is started, the generator begins to generate AC which is internally converted to DC. This current is then supplied to the vehicle's electrical system through the output circuit B+ terminal of the generator.

Once the generator begins generating current, a voltage signal is taken from the generator stator and fed back to the regulator.

With the system functioning normally, the generator output current is determined by the voltage of the A circuit. The A circuit voltage is compared to a set voltage internal to the regulator, and the regulator controls the generator field current to maintain the correct generator output.

The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. This allows for better battery recharge in the winter and reduces the chance of overcharging in the summer.