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