Synergic control in MIG welding using a thyristor controlled power source - steady d.c. open arc and short-circuiting arc operation

TWI Industrial Member Report Summary 346/1987

Naseer-Ahmed and M Amin

Scope

Synergic control units have already been developed at The Welding Institute for steady d.c. open arc and short-circuiting arc operation using a transistor controlled power source. Because of their lower cost, thyristor controlled power sources are more widely used in industry. This report considers the feasibility of adapting the control units to a thyristor controlled welding power source.

Two approaches have been adopted in accommodating the control of thyristor power sources. In one approach, the generatised control equation used previously for the transistor power source has been extended to take account of the characteristics of the thyristor power source. As an alternative, the control units themselves have been modified to allow for the different power source characteristics.