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Analog Electronics
respect to which it is being measured, in that order:
thus v,„ is the voltage at node 1 with respect to 0 V
ground. Because of the very large voltage gain of
an opamp, for any value of its output voltage its
two input terminals must be at virtually the same
voltage - assuming of course that it is not over-
driven, in which case the output voltage would be
stuck at one or other supply rail voltage. We
therefore know that the voltage at node 3 with
respect to ground is 1
L.
0° and at node 5 it is also
1 L 0° for the same reason. Furthermore, node 1 is
connected only to an opamp input, which draws
negligible current: therefore ...