The power for performing {TAIL ~ the operational functions} is provided by {HEAD ~ the battery} when the interface is inactive and by the host device when the interface is active 
The power for performing { TAIL ~ the operational functions } is provided by { HEAD ~ the battery } when the interface is inactive and by the host device when the interface is active
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH