Patent ID: 8581146

Claim:
A welding wire feeding apparatus, comprising: a control device which positions a welding gun a set distance above a work piece to be welded; a wire feeding device which feeds a wire to said welding gun; a power source which provides a current and a voltage to said wire while said wire feeding device is feeding said wire; and a short circuit detection circuit coupled to said wire feeding device, wherein when said short circuit detection circuit detects a short circuit in at least one of said wire and said welding gun, said wire feeding device stops feeding said wire based on said detection of said short circuit, and wherein said welding gun comprises a contact tip and said short circuit detection circuit causes said wire feeding device to stop said wire such that a stick out distance of said wire with respect to said contact tip is said set distance, said short circuit detection circuit including a power supply to apply a voltage to at least one of said wire and said contact tip and a voltage monitoring system for monitoring the voltage in the at least one of said wire and said contact tip and comparing the monitored voltage to a reference voltage.