{TAIL ~ The control voltage UST} is coupled to {HEAD ~ a half wave rectifier D}, which produces a half wave voltage signal 
{ TAIL ~ The control voltage UST } is coupled to { HEAD ~ a half wave rectifier D } , which produces a half wave voltage signal
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH