| 摘要 |
PURPOSE:To protect the device from breakdown by connecting the commutation element of an AC power source and the firing element of a main circuit capacitor with the power source for a control circuit. CONSTITUTION:A variable speed driver for an AC motor comprises a main circuit commutation element 1, an inverter circuit 2, a main circuit smoothing circuit 4, a control circuit 6, and the like. Power is fed from (-) side of a commutation element 3 and the main circuit commutation element 1 to the control circuit 6. A self-firing element 6 to be turned ON by the control circuit 6 is also provided in order to supply charges from the capacitor 4 to the control circuit 6. |
