a microprocessor connected to the battery through {HEAD ~ a regulator} to obtain {TAIL ~ a suitable DC voltage}, the power supply switch and the illumination switch 
to obtain
a microprocessor connected to the battery through { HEAD ~ a regulator } to obtain { TAIL ~ a suitable DC voltage } , the power supply switch and the illumination switch
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH