| 摘要 |
PURPOSE:To reduce the switching loss of a main transistor by applying a negative pulse voltage of a pulse generator output to the base terminal of a main transistor in the phase inverted from ON state to OFF state in the main transistor. CONSTITUTION:When a signal voltage v1 of a zero point detecting winding 16e is positive, a transistor 25 is turned ON, and a transistor 24 is turned OFF. Accordingly, a transistor 18 is turned OFF, a transistor 19 is turned OFF, and a capacitor 20 is charged by a power source 11. On the other hand, the capacitor 21 remains charging state. When a zero point detecting winding voltage V1 drops to 0V, the transistor 25 is turned OFF, and the transistor 18 is turned ON. Thus, the capacitor 20 is discharged, a pulselike reverse base voltage is applied to the transistor 12, and the transistor 12 is turned OFF. Similarly, the transistor 13 is turned OFF immediately before the zero point detecting winding voltage v1 is inverted from negative to positive. |
