A drive circuit selectively applies current to each electromagnet to effect {TAIL ~ rotational force} on {HEAD ~ the rotor poles} 
A drive circuit selectively applies current to each electromagnet to effect { TAIL ~ rotational force } on { HEAD ~ the rotor poles }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD