Pulse Generator for High-Current AC-MIG Welding Process

Development of AC-MIG Welding Process (Report 2)

Abstract

A pulse generator with a L-C-R circuit sympathized with the industrial frequency has been developed to facilitate the arc re-ignition in the high-current AC-MIG welding process.
Weld-defects can be avoided in this process because of lower arc pressure exerting on molten pools than in conventional DC-MIG. Furthermore, this process provides low oxygen weld metal with high toughness. Further improvement had been desired in the reliability of a Pulse Generator in order that this process can be used in practice.
It has been clarified that the most important parts in the pulse generator is thyristors as switches in the L-C-R circuit which need a considerable allowance against high pulse current and voltage.