| 摘要 |
PURPOSE:To turn on a semiconductor switch in both ways by flowing a current to the base of the semiconductor switch invariably in a bias direction through a switching circuit corresponding to the direction of a current which flows to a main circuit. CONSTITUTION:The primary winding 61 of a current transformer 61 is inserted into the main circuit of a transistor TR2. The secondary winding of the current transformer 6 consists of forward winding 62 and backward winding 63 so that voltages having the opposite polarities are developed at the other terminal of the winding 62 and the other terminal of the winding 63. When a current flows forward through the main circuit of the TR2, the current is supplied from the winding 62 to the base of the TR2 through a diode 7 in the forward bias direction. When the current flows reversely through the main circuit of the TR2, on the other hand, the current is supplied from the winding 63 to the base of the TR2 through a diode 7 in the forward bias direction. |
