Dear all,
Previously I had a piezo-transducer connected as follows in differential mode as shown in the attached doc figure 1. However the signal from the transducer is tiny so I added an op amp to the circuit. Now that i've done this (NRSE or RSE mode) i no longer pick up the vibrations from the transducer I just get a 50hz noise signal. I've tried several different ways of wiring this including wiring the op amp differentially as shown in figure 1 and connecting that differentially with ground as the negative into the daq card. This seemed to work until I tried reading from two channels at once which caused the inputs to drop to -1v the negative limit set in MAX. I'm using a PCI-1200 and traditional DAQ. Any help wiring this thing would be much appreciated. I've probably made a novice mistake. But I can't figure out where i've gone wrong reading through the literature on this site.
Thanks,
Matt
