Hi Rex I was reviewing your drawings and had a question about the bridge and subsequent circuit. STM's drawing shows the ref oscillator going into an inverting configured amp with gain of 100, followed by an inverting amp with gain of one. They both go into different pins of the demodulator. As I read your drawing , you have two inverting amps with gain of 100 connected to the bridge ends. Is this equivalent? I don't know. It seems in your circuit that the two amps would have the same sign where in STM's circuit they are of opposite sign. Karl's lvdt demodulator( which I currently use) is more like STM's in that one uses the switch to selectively choose one signal or the other depending on sign ( a rectifier). Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>