control means for supplying a control signal varying {TAIL ~ the inductance} of {HEAD ~ the inductive means}, 
control means for supplying a control signal varying { TAIL ~ the inductance } of { HEAD ~ the inductive means } ,
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH