As one skilled in the art understands, a normal switching power supply first converts {HEAD ~ the incoming AC} into {TAIL ~ a DC source} 
into
As one skilled in the art understands , a normal switching power supply first converts { HEAD ~ the incoming AC } into { TAIL ~ a DC source }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL