The core ends are arranged relative to the teeth such that 1) when both coils are energized to induce {HEAD ~ poles} in the teeth, at least three consecutive teeth will be magnetized with {TAIL ~ alternate polarity}, and 2) when one of the coils is deenergized, the fields will be unbalanced to impose a rotational force on the rotor 
The core ends are arranged relative to the teeth such that 1 ) when both coils are energized to induce { HEAD ~ poles } in the teeth , at least three consecutive teeth will be magnetized with { TAIL ~ alternate polarity } , and 2 ) when one of the coils is deenergized , the fields will be unbalanced to impose a rotational force on the rotor
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH