{HEAD ~ A train} of {TAIL ~ positive going pulses} is fed to the base electrode of transistor Q1 by controller 14 via line 15 
{ HEAD ~ A train } of { TAIL ~ positive going pulses } is fed to the base electrode of transistor Q1 by controller 14 via line 15
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH