| 摘要 |
A wire feeder for an electric arc welder comprising feed rolls driven by an electric motor for moving a welding wire toward a workpiece for an arc welding process. The motor is rotated at a speed determined by a WFS signal from a controller when energized by actuation of a start switch, a switch network has a first condition allowing the motor to operate at the speed determined by the WFS signal and a second override condition forcing the motor to rotate at a fixed lower speed, a toggle circuit with a first position to shift the switch network into the second condition upon actuation of the motor start switch and a second position to shift the switch network to the first condition upon receipt of a toggle signal, and a device to create the toggle signal when the load current to the motor exceeds a given value. |
