A set up circuit is coupled to {HEAD ~ the sensor}, the power source, and {TAIL ~ the wire feeder} 
A set up circuit is coupled to { HEAD ~ the sensor } , the power source , and { TAIL ~ the wire feeder }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL