ok i will try to explain ,,my opamp inverting amp output is 4.7v normally..and when i put a load of 120gm on load cell the output switches to 5.4v...actually i wanted to drive a relay with its output but i think the current needed by the relay is more than that of the current given by 741........so i decided to use a lm311 as comparator....i gave output of the 741 to input of the lm311...and i prepared 5.1 as refernce voltage by means of a voltage didvider ckt using different battery suppy...but when i connect the 5.1 supply(from battery) to the refence of comparator for comparing then my input vltg(that i fed earlier i.e 4.7 from 741) rises automatically to 5.5 always above the reference vtg.....why this is happening can anyone help me on this?