GB182970A - Improvements in or relating to electric welding and apparatus therefor - Google Patents

Abstract

182,970. Davies, W. Langdon-, and Soames, A. April 28, 1921. Lighting and heating systems. - An alternating-current welding-apparatus is provided with an electromagnet which operates to introduce an inductance into the arc circuit or into the primary circuit of a transformer supplying the arc circuit when the arc is established. Additional contacts or switch may be provided to cut out an inductance in the arc circuit or in the primary circuit of the transformer before the arc is established, after which the working inductance is inserted. An inductance A, Fig. 1, is inserted in the circuit of the arc by means of an electromagnet C when the arc is established. In a modification, several inductances are provided and the amount to be introduced is varied by means of a switch. In the arrangement shown in Fig. 3, the solenoid C inserts the inductance A<4> in steps. In the arrangement shown in Fig. 5, a protective inductance A<6> is at first cut out by the switch D<2> and the inductance A<7> is inserted by the switch D after the arc has been struck. In a modification, the protective and the working inductance are controlled by a single switch. In the arrangement shown in Fig. G, the protective inductance A<6> is placed in the primary circuit of the transformer and the working inductance A<8> in the arc circuit, both inductances being controlled by a single electromagnet C. In a further modification, the inductances A<6>, A', Fig. 6, are controlled by separate electromagnets.