the first power supply supplies a first power supply voltage obtained by adding a voltage corresponding to a forward voltage drop of {HEAD ~ the first and third diodes} to {TAIL ~ the first predetermined voltage}, and 
to
the first power supply supplies a first power supply voltage obtained by adding a voltage corresponding to a forward voltage drop of { HEAD ~ the first and third diodes } to { TAIL ~ the first predetermined voltage } , and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH