GB622836A - Improvements in or relating to rectifier control systems - Google Patents

Abstract

622,836. Switching systems for consumption apparatus. WELTRONIC CO. Sept. 20, 1946, No. 28225. Convention date, Dec. 15, 1944. [Class 38 (iv)] In an electrical network including an ignitron valve, for controlling the supply from an A.C. source, the primary and secondary windings of a transformer are connected respectively between the anode and cathode, and cathode and igniter of the valve, a rectifier being connected in the secondary circuit so that the current to the igniter is limited in duration. A resistance welding circuit is supplied through a pair of reversely connected rectifiers 10, 12, each having an immersed electrode i supplied from secondaries 20, 24 of a transformer CT, the primary 26 of which is connected between the rectifier anodes. In each half-cycle, while a manually or automatically controlled switch 28 is closed, that immersed electrode i, as determined by unidirectional conductors 18, 22, is energized in the valve with the positive anode. That valve conducts and short-circuits the transformer primary 26 to prevent further current through the electrode i.