The speed control module controls a speed of {TAIL ~ a motor} based on an error signal generated based on a desired speed and {HEAD ~ back electromotive force} 
The speed control module controls a speed of { TAIL ~ a motor } based on an error signal generated based on a desired speed and { HEAD ~ back electromotive force }
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD