a timing circuit in electrical communication with {HEAD ~ said output means} of said {TAIL ~ electrical energy source} 
of
a timing circuit in electrical communication with { HEAD ~ said output means } of said { TAIL ~ electrical energy source }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL