摘要 |
<p>PURPOSE:To prevent breakdown of a voltage regulator and a loaded device due to generation of an overvoltage caused by a fault of an engine governor or the like, by reducing the number of revolutions of an engine by making a slow-down solenoid operate even when the voltage of a capacitor for smoothing an exciting lower supply rectification voltage of an exciter coil exceeds a reference value. CONSTITUTION:When an engine governor is faulty or a capacitive load is connected, the voltage of a stator coil rises and the voltage of a smoothing capacitor 23 in a voltage regulator 2 rises higher. When the voltage of the capacitor 23 rises to a prescribed value or above, a current flows through a constant voltage diode 33, a photodiode 34A turns ON, hereby a transistor 34B is turned ON, and the current flows through a slow-down solenoid 40, which lowers the number of revolutions of an engine and also an output voltage of the stator coil 15. When the number of revolutions of the engine lowers, an output frequency also lowers, a load impedance turns high in the case of the capacitive load, and thus a load current is suppressed.</p> |