Microprocessor-based arc voltage control for gas tungsten arc welding using gain scheduling

Limitations of the traditional automatic voltage controller (AVC) for gas tungsten arc welding are explained and the characteristics of the welding arc that cause these limitations are presented. The design of an adaptive AVC using a microprocessor-based controller is described. The enhanced AVC uses gain scheduling to maintain optimum gain in the feedforward loop of the system and offers a constant arc length control mode which is useful under conditions where the welding currents is varied over a wide range.<
>