{HEAD ~ The rate} of change of the flux in the primary winding induces {TAIL ~ a voltage} in a sensing winding, which voltage is integrated and used to control the on time of the switching device so as to control the flux in the main coil 
induces
{ HEAD ~ The rate } of change of the flux in the primary winding induces { TAIL ~ a voltage } in a sensing winding , which voltage is integrated and used to control the on time of the switching device so as to control the flux in the main coil
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL 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 OTH OTH OTH OTH OTH