A plurality of control power sources of voltage specifications different from one another are constructed. A generator output converted by a converter into a DC current is converted by an inverter into an AC current of a predetermined frequency. The generation output is rectified by second rectifier circuits and a capacitor and is then input to an RCC. The RCC constitutes a self-excited oscillation circuit, energy is stored into a transformer in an ON time of a transistor corresponding to an oscillation frequency thereof, and the energy is transferred to a secondary side in an OFF time. In the secondary side of the RCC, windings are formed corresponding to the number of required power sources. One group of windings forms both positive and negative power sources of a control power source, and another group of windings forms a power source for an FET driver.