A voltage regulator maintains a generator's output voltage by modifying the field current. The shunt coil is responsible for exciting the field windings by carrying current. When the generator operates at low speeds, increased current flows through the shunt coil to ensure adequate field strength. As the generator's speed escalates, its output voltage naturally increases. To maintain a stable output voltage, the regulator decreases the current flowing through the shunt coil. This reduction in field current weakens the magnetic field, thereby stabilizing the output voltage. Consequently, an increase in speed results in a decrease in the current through the shunt coil.