| 摘要 |
1,120,540. Protective arrangements. SIEMENS A.G. 13 Dec., 1966 [17 Dec., 1965], No. 55892/66. Heading H2H. Over-voltages across the secondary winding of a transformer feeding a flash butt welding machine are reduced by shunting the winding with a resistor in series with a pair of reverse parallel connected thyristors or a bipolar semiconductor diode chain, the thyristors or diodes being rendered conductive on voltages exceeding the normal voltage crests. |
