{HEAD ~ The engine} can be run at {TAIL ~ varying speeds} causing the generator to give variable frequency AC electrical power output which is converted by the frequency converter means to an AC electrical power output having substantially the predetermined constant frequency of the mains 
run at
{ HEAD ~ The engine } can be run at { TAIL ~ varying speeds } causing the generator to give variable frequency AC electrical power output which is converted by the frequency converter means to an AC electrical power output having substantially the predetermined constant frequency of the mains
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL 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 OTH OTH OTH OTH