| 摘要 |
PURPOSE:To eliminate the operation stop owing to the detection of overcurrent and to improve welding efficiency by setting the output pulse width for the prescribed time in the initial period of current conduction of an inverter interposed between a power source and welding gun smaller than the laser width. CONSTITUTION:(A) denotes the pulse current I to be applied to control poles of transistors 51-54 constituting the inverter 5 and (B) denotes the welding current IS flowing in the welding gun 8. The width of the pulse current I is set small so as to pass, for example, 1/2 current with respect to the current during the later current conduction for the prescribed time after the start of the current conduction to a connection circuit in the above-mentioned way and therefore the generation of the transient overcurrent owing to the magnetic saturation, etc. of the iron core of a welding transformer 6 for welding in the initial period of the current conduction is obviated. The operation stop owing to the detection of the overcurrent is thus prevented. |
