{HEAD ~ The controller shifts} available {TAIL ~ power} between the first lighting source and the second lighting source 
{ HEAD ~ The controller shifts } available { TAIL ~ power } between the first lighting source and the second lighting source
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH