FEED MOTOR CONTROL CIRCUIT FOR AUTOMATIC ELECTRIC ARC-WELDER

摘要

An electrode feed motor control circuit for an automatic electric arc welder which gives improved starting. For cold starts, the electrode feed motor is instantaneously braked when the electrode first contacts the workpiece so that the electrode is lightly touching the workpiece and the electrode motor field is energized for pull back preparatory to the weld start. For hot and cold starts, the motor speed more rapidly responds to transitional meltoff requirements. The motor speed is automatically limited until the arc is fully established.