A New System for D-C. Arc Welding

A short description is first given of a d-c. generator having characteristics suitable for arc welding. Curves showing performance under steady conditions of load are shown. It is pointed out that for quick changes of load transients appear detrimental to arc welding. In order to eliminate these transients, an external inductive device called a transforming reactor is introduced in the arc welding circuit. This transforming reactor has a dual purpose. First, it depresses the transients as is shown by oscillograms, resulting in quick recovery of the voltage and a small short-circuit current. Thus it is shown that under arc welding load the generator performs in accordance with the curves corresponding to a steady load. Second, the transforming reactor introduces reactance in the arc circuit which, experience has shown, is desirable in order to make the arc stable and therefore easy to handle. The system for d-c. arc welding which is described consists, therefore, of two units,-a generator and a transforming reactor, forming a combination capable of producing uniform welds of high strength.