| 摘要 |
971,461. Supply systems for resistance welders; converting. H. A. SCHLATTER A.G. Feb. 24, 1961 [Feb. 26, 1960], No. 6877/61. Headings H2F and H2H. A flush butt resistance welder is controlled from a 3-phase supply 10 by ignitrons 4-9 controlled for preheating to supply groups of half-wave pulses first of one polarity and then the other with an interruption between groups, and to supply for flushing smaller groups of half waves with no interruption which are effectively of higher frequency. |
