TWI Industrial Member Report Summary 284/1985
M Amin and Naseer-Ahmed
Control methods of existing one-knob MIG welding power sources developed to simplify the setting-up of welding conditions, for both steady d.c. and short-circuiting arc operations, have been studied. These methods essentially execute predetermined parametric relationships. Electrical and electronic circuits control the power supply and wire feeder to maintain constant arc voltage or a constant arc length over the operating range. For arc length control, the 'stepwise' approach is simple to achieve but limited to a small number of welding conditions; whereas the 'continuous' approach enables any required welding condition to be established using either a 'rising' or 'flat' output characteristic of the power supply unit.