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How are they used to measure anything? The only thing I can think is that they are used in conjunction with some other device -- I would bet that this other device is what is actually used to measure... thought? Jheiv ( talk) 01:09, 26 June 2008 (UTC)
Miller theorem is a general concept that does not depend on the specific circuit implementation (tube, transistor, op-amp, etc.) It only requires two voltages in proportion V2/V1 = K to be applied to the two ends of an impedance element (a galvanometer here). In our case, the proportion is V2/V1 = 1 and it is obtained by a manually controlled voltage follower with series negative feedback. The supplying voltage source and the potentiometer constitute a regulated voltage source producing V2 that is placed contrary and in series with the input voltage V1. Thus the two voltages are subtracted according to KVL and their difference Vdiff = V1 - V2 is applied to the galvanometer acting as a zero indicator. The man monitors continuously Vdiff looking at the galvanometer and adjusts V2 equal to V1. So, this arrangement acts as a voltage follower and the resistance seen from the side of the input voltage source is virtually increased up to infinite. Circuit dreamer ( talk, contribs, email) 17:57, 4 August 2010 (UTC)
This article has not yet been rated on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||
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How are they used to measure anything? The only thing I can think is that they are used in conjunction with some other device -- I would bet that this other device is what is actually used to measure... thought? Jheiv ( talk) 01:09, 26 June 2008 (UTC)
Miller theorem is a general concept that does not depend on the specific circuit implementation (tube, transistor, op-amp, etc.) It only requires two voltages in proportion V2/V1 = K to be applied to the two ends of an impedance element (a galvanometer here). In our case, the proportion is V2/V1 = 1 and it is obtained by a manually controlled voltage follower with series negative feedback. The supplying voltage source and the potentiometer constitute a regulated voltage source producing V2 that is placed contrary and in series with the input voltage V1. Thus the two voltages are subtracted according to KVL and their difference Vdiff = V1 - V2 is applied to the galvanometer acting as a zero indicator. The man monitors continuously Vdiff looking at the galvanometer and adjusts V2 equal to V1. So, this arrangement acts as a voltage follower and the resistance seen from the side of the input voltage source is virtually increased up to infinite. Circuit dreamer ( talk, contribs, email) 17:57, 4 August 2010 (UTC)