Characterization of electrical properties of resistance welding machines

摘要

Due to the individual electrical and mechanical characteristics of resistance welding machines,choice of the right machine and welding parameters for an optimized production is often difficult. This is especially the case in projection welding of complex joints. In this paper,a new approach of characterizing the electrical properties of AC resistance welding machines is presented,involving testing and mathematical modelling of the weld current,the firing angle and the conduction angle of silicon controlled rectifiers with the aid of a series of proof resistances. The model predicts the weld current and the conduction angle (or heat setting) at each set current,when the workpiece resistance is given.