METHOD OF CONTROL AND APPARATUS FOR HOT-WIRE WELDING

摘要

Hot wire TIG welding process is controlled by a system in which the primary of a main transformer (15) is connected to a triac (16) while the secondary is connected to a full-wave recitifer circuit including diodes (17,18), forming a wire-heating circuit (19). A gate pulse- forming circuit (20) produces a wire current with the AC power supply of commercial frequency, subjected to phase control. A wire contact detector (21) detects whether the wire tip (6) is in contact with the base metal (3), applying a high or low signal to an on-off control circuit (22) in the gate pulse-forming circuit, operating not to form the next energisation pulse if the wire is detached from the base metal.