Hence, the frequency of operation of the power converter may be varied for {HEAD ~ regulation purposes} without losing {TAIL ~ the efficiency advantages} of a narrow bandwidth drive 
without losing
Hence , the frequency of operation of the power converter may be varied for { HEAD ~ regulation purposes } without losing { TAIL ~ the efficiency advantages } of a narrow bandwidth drive
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH