GB1412300A - Arc generator - Google Patents

Abstract

1412300 Arc discharge R SATO 28 Sept 1972 [28 Sept 1971 19 April 1972] 44895/72 Heading H5H [Also in Division B3] Each voltage phase, R, S, T of a star connected transformer secondary of a three phase transformer A, Fig. 1, is connected via a regulator B to a respective electrode IR, IS, IT, so that arc discharges occur between the electrodes. The neutral point of the star connected transformer secondary may be coupled via a regulator to a fourth electrode or to the workpiece. Alternatively one of the phases may be connected to the workpiece as in Fig. 5 (not shown). The regulator may be a thyristor. A plurality of sets of electrodes may be connected in parallel, e.g. Fig. 7, and each primary loop of the transformer, Fig. 8, may be associated with two secondaries. Deep welds, Fig. 9, may be formed by using additional preheat and after heat electrodes 1, 3, the neutral connection d being switched between the two workpieces C<1>, C. The arrangement of Fig. 1 may be used to provide a plasma discharge when located in a gas stream in a nozzle. Fig. 11 (not shown) indicates electrode arrangements using combinations of electrodes, e.g. different metals, auxiliary material, flux and hollow section electrodes. The rotating magnetic field associated with the A.C. current may be used to vibrate the molten materials. The device may be used in welding, cutting, metallizing and heating.