| 摘要 |
PURPOSE: To simplify the power source of a driving circuit for driving a switching semiconductor element. CONSTITUTION: When a GBT element 9 is turned off and an IGBT element 19 is turned on, capacitors 1, 2 are charged by the current sequentially passing from a high potential DC bus 30 through the capacitor 1, a resistor 4, a diode 5, the capacitor 2 and an intermediate wiring 32. Simultaneously, a capacitor 11 is charged by the current sequentially fed from a low potential DC bus 31 through a diode 17, a resistor 16 and the capacitor 11 to the wiring 32. Contrary, when the element 9 is turned on and the element 19 is turned on, the capacitors 11, 12 are charged, and the capacitor 1 is discharged. The above operation is repeated to hold the power source voltages of driving circuits 8, 18 a predetermined or more value. Accordingly, the power source for the driving circuits is formed of simple circuit elements. |
