20140175065 | Welding-Current Control Method of the Resistance Welding Machine and Welding-Current Control Device - In spot welding, the condition tolerance for applying a large current in a short time into an aluminum alloy plate or the like is narrow, and also nugget crack sometimes occurs in spot welding. In the case of a mild steel plate, the expulsion sometimes occurs, and thereby a poor weld portion is formed. Due to a pickup removal operation from an electrode tip, the operating ratio is reduced. Here, a PAM control method is employed for raising or dropping a rectified and smoothed voltage E | 06-26-2014 |