{TAIL ~ a voltage regulator}, selectively enabled and disabled in response to {HEAD ~ a control input}, a pair of voltage monitors, 
{ TAIL ~ a voltage regulator } , selectively enabled and disabled in response to { HEAD ~ a control input } , a pair of voltage monitors ,
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH