| 摘要 |
PURPOSE:To provide a consumable electrode type arc welding machine which has improved arc startability by determining the start time limit proportional approximately to an arc-off period when said period is below a predetermined specified period. CONSTITUTION:A step up-down circuit 22 counts up the signal of a welding current detecting circuit 21 in arc periods TA1, TA2 and the count values saturate at the specified value. Said circuit counts down the signal by the inversion output from a circuit 21 in off periods AA01, AA02. The count value progresses like A1-A5 and is not made zero in the short off period TA01 but is made zero in the off period TA02 longer than the predetermined specified period. Then the value shown by an arrow B is made to the value proportional approximately to the off period TA01 in the off period below the prescribed off period. The above- mentioned value B is converted to voltage and is inputted to a start time limit setter 13a by which the time limit output signal proportional approximately to the off period TA01 is obtd. |
