Simultaneous Operation of Electric Arcs from the Same Supply

A simple technique is described which enables two arcs to be operated from a single dc power supply over a wide range of operating conditions. The conditions for stabilizing coalesced arcs have been analyzed as an unbalanced bridge circuit and solved using a computer. The results indicated that the part of the arc adjacent to the electrode to which the stabilizing resistance was connected was stable and that the part of the arc adjacent to the other electrode was unstable when single individual stabilizing resistors were used for each arc. If the stabilizing resistance was shared equally on both sides of the arc both parts were stable and large volume discharges were produced. The technique may be extended to more than two arcs and the results may be applicable to arc processes used for welding, enabling simultaneous operation of several welding arcs from a common supply, surface deposition, plasma processes used for metallurgical reduction and chemical synthesis, and for the stimulation of laser excitation in gas lasers where increased efficiencies and higher powers may be obtained.