| 摘要 |
PURPOSE:To provide a power supply apparatus which is advantageous to cost by simplifying the structure of the apparatus to increase the productivity thereof. CONSTITUTION:A high-frequency pulse wave outputted from a chopper circuit VS1 is made into a direct-current voltage with the current-limiting and smoothing of an inductor L and a capacitor C1, which is supplied to an inverter circuit made of switching elements Q1 to Q4. The inverter circuit is driven by a controlling power supply VS2 and phase inverter circuits A1 to A3. A constant-current circuits J1, J2 are connected to the gate of the switching elements Q1, Q3 in which floating drive is required, and a current required for these constantcurrent circuits J1, J2 is supplied from a driving power supply PS. Thereby, a bias voltage is applied to the gate G of the switching elements Q1, Q3 so that the switching operation may be improved. |
