| 摘要 |
PURPOSE: To enable highly reliable and suitable excitation for a welding arc by attaining the high speed of a current rise in an arc gap between an electrode and an article to be welded through the use of a semiconductor switch, and thereby causing dielectric breakdown of the arc gap. CONSTITUTION: With an additional lead 20 provided for a semiconductor switch 6, the second lead of the secondary winding 3 in a welding transformer 1 is connected to one lead of the secondary winding 15 in a pulse transformer 7 through a current controller 17. In addition, it is connected to other AC lead of a rectifier bridge 13 through an additional capacitor 14. By the use of the semiconductor switch 6, a current rise is speeded up in the arc gap between an electrode and an article to be welded, and the dielectric breakdown of the arc gap is executed. Consequently, highly reliable and suitable excitation can be performed for a welding arc. |
