| 摘要 |
PURPOSE:To provide a titled device which breaks down first the insulation of an oxide film to assure satisfactory and normal low-voltage welding for succeeding welding by passing current between welding base metals for the beginning from relatively high voltage power source circuit and switching the circuit to a low voltage power source circuit after the detection of the current conduction. CONSTITUTION:Current is conducted between welding base metals 4a and 4b from a relatively high voltage power source circuit 1 for the beginning to pass the current which breaks down the oxide film layer on the surface in the case of impressing electric power between said base metals and welding the base metals. A switching control circuit 3 is operated upon detection 5 of said current conduction to switch the circuit to a low voltage power source circuit 2 for normal welding to continue welding. The base metals are easily welded even if the oxide film is present on the surface of the base metals and welding start is difficult. |
