In our previous paper, it was for the first time clarified the radio noise was considerably generated during mere A.C. arc welding and cutting without high frequency. A further study on such a noise has been carried out at D.C. arc, the results of which are reported here. The summary is as follows.
The interfering voltage of the distribution line produced during D.C. arc welding and cutting is comparatively as large as in the case of A.C. arc, but the interfering voltage in D.C. arc is reduced to the great extent by the use of a group of condensers, the fact being different from the case of A.C. arc.
The interfering radiation during D.C. arc welding and cutting is comparatively small as same as the case of A.C. arc.