The armature 23 and {TAIL ~ pole piece} 24 are preferably fabricated from a magnetic material, such as {HEAD ~ soft iron} 
The armature 23 and { TAIL ~ pole piece } 24 are preferably fabricated from a magnetic material , such as { HEAD ~ soft iron }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD