| 摘要 |
PROBLEM TO BE SOLVED: To provide a weldment electric power unit in which a capacity of an auxiliary transformer can be reduced.SOLUTION: A weldment electric power unit for performing thyristor phase control which comprises, in a power supply unit 11 thereof, a main transformer 111, a thyristor circuit 112 to which an output of a first secondary side winding of the main transformer 111 is inputted, an auxiliary transformer 113, and a changeover circuit 114 for performing changeover between a first state that an output power of a second secondary side winding of the main transformer 111 is outputted and a second state that an output of the a secondary side winding of the auxiliary transformer 113 is outputted. An output power of the changeover circuit 114 is supplied to a wire feed device via electric power transmission lines 51, 52. the changeover circuit 114 is changed to the first state when a high power is required, and the changeover circuit 114 is changed to the second state when a high power is not required. The auxiliary transformer 113 used in the second state is not required to output a high power, and therefore can be configured from a transformer of a small capacity.SELECTED DRAWING: Figure 3 |
