How Voltage Regulators Work

Since the gear ratio of the generator to the engine is fixed, the speed of the generator will vary with the speed of the engine. During the operation of the car, the engine speed changes in a wide range, and the terminal voltage of the generator will also change in a wide range with the change of the engine speed. The generator needs to supply power to the electrical equipment and charge the battery, and its voltage is required to be stable. Therefore, in order to keep the voltage basically unchanged at a certain value, the output voltage of the generator must be adjusted.