Various alternative embodiments are used to improve the efficiency of {HEAD ~ the head} by channelling the magnetic flux outside {TAIL ~ the gap} 
Various alternative embodiments are used to improve the efficiency of { HEAD ~ the head } by channelling the magnetic flux outside { TAIL ~ the gap }
OTH OTH OTH 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