GB527782A - Improvements in direct-current arc-welding generators - Google Patents

Abstract

527,782. Exciting dynamos. WILSON WELDER & METALS CO., Inc. April 15, 1939, No. 11507. Convention date, April 16, 1938. [Class 35] A D.C. generator for arc welding comprises a four-pole series-wound armature 3, a field magnet having four poles, a single field winding 5 for producing a constant, work field through one pair of adjacent poles 1, and a single series winding 6 for producing a counter-field through the opposite pair of adjacent poles 2, 2a the constant-field and series field windings being located on;adjacent poles; a shunt field winding 7 opposing the series winding 6 is provided on the pole 2 opposite the pole 1 carrying the constant field winding and the remaining pole 1 is either unwound or carries an additive shunt winding 23, the pole preferably being magnetically saturated. The winding 5 is shown connected through a polarity reversing switch 40 and a rectifier 46 to a portion 42a of the stator winding of an induction motor driving the generator, or a substantially constant field may be obtained by substituting for the winding 5 cumulative shunt and series windings, the pole being magnetically saturated to vary the current output, the pole 2a carrying the series winding 6 has a central part 31 which can be moved in or out by a hand wheel 32. Further adjustment is possible by tapping a field winding 6 and providing a switch 36 to connect either the whole or part of this winding in circuit.