{HEAD ~ The system} 1, wherein {TAIL ~ the back EMF} is induced in a sensing coil separate from the stator coil 
wherein
{ HEAD ~ The system } 1 , wherein { TAIL ~ the back EMF } is induced in a sensing coil separate from the stator coil
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH