| 摘要 |
PROBLEM TO BE SOLVED: To simply and surely inspect a magnetization biasing current generated in a control circuit of a resistance welding apparatus.SOLUTION: Variation of the magnetic flux is detected without attaching and detaching a primary wire 16 to and from an inverter type resistance welding control device 12 by relatively moving a detection unit 51 of a magnetization biasing current measuring instrument so as to trace the surface of the primary wire 16. Also, the detection result at a position where the current gain is high is effectively utilized for current detection by that the detection unit 51 is relatively moved intentionally with respect to the surface of the primary wire 16 and detects variation of the magnetic flux during the time considering the variation of the current gain of the primary wire 16 having an internal structure of twisting three single lines normally. Further, determination accuracy of presence/absence of the magnetization biasing current can be improved by determining presence/absence of the magnetization biasing current A in the primary wire 16 only when an output of the detection unit 51 is equal to or larger than a predetermined output value. |
