A ratio of IP/IA of {HEAD ~ the currents} flowing in {TAIL ~ the terminals P} and A is detected 
flowing in
A ratio of IP / IA of { HEAD ~ the currents } flowing in { TAIL ~ the terminals P } and A is detected
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH