| 摘要 |
PURPOSE:To lessen shortcircuit current and prevent generation of spatter, by gradually decreasing output current for a specified time after generation of an arc between a wire fed at nearly constant speed and a base metal, and gradually increasing output current after short-circuiting until generation of an arc. CONSTITUTION:A transistor 3 is made off by output of the first rectifier circuit 1 a specified time after generation of an arc in a welding load 5 connected in series to this through a transistor 3 and a reactor 4, and made on further after a specified time. Output current decreases gradually after generation of an arc and after the transistor 3 is made off, further decreases slowly from the value of output voltage of the first rectifier circuit 1 to voltage of the second rectifier circuit 2 connected in parallel with small output voltage. When the transistor 3 is on, voltage rises slowly to output voltage of the first rectifier circuit 1, and output current also increases gradually. By this way, heat inputting is made as far as possible after generation of an arc until next shortcircuit to facilitate regeneration of arc and suppress generation of spatter. |
