| 摘要 |
PROBLEM TO BE SOLVED: To provide a welding controller of a seam welding machine, the controller which stabilizes a welding current to improve welding quality and which is inexpensive and miniaturized. SOLUTION: A seam welding machine is equipped with: a welding transformer 10 that supplies a welding current to a workpiece held between disk-like electrodes 11, 11; a thyristor circuit 12 that is interposed between the primary side of the welding transformer and a single phase AC power source and drives the welding transformer; a current detector 15 that detects an electric current value on the primary side of the welding transformer; and the main controller 16 that controls the entire welding machine including the firing angle control of the thyristors 13, 14 of the thyristor circuit 12, wherein such operation is repeated that the current values on the positive and the negative side are detected respectively for each energization by the current detector 15, a target set current value and a detected current value are compared/calculated by the main controller 16 to determine a corrected value of the firing angle of the thyristor, then on the basis of the corrected value, the next thyristor firing angle is controlled. COPYRIGHT: (C)2006,JPO&NCIPI
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