Position sensor exploits Faraday's Law

Abstract: This application note starts by explaining Faraday's Law. The note then shows how a voltmeter and connecting wires serve as a positional sensor. A rail-to-rail I/O comparator and a few simple components form an amplitude detector that compares the sinewave amplitude with a DC voltage. The MAX985 rail-to-rail I/O op amp is featured in the design.