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Entry  Fri Jul 18 19:41:09 2008, Yoichi, Update, PSL, PMC PZT investigation Hysteresis.pngStepResponse.png
    Reply  Fri Jul 18 23:24:24 2008, rob, Update, PSL, PMC PZT investigation 
       Reply  Sat Jul 19 19:39:44 2008, rob, Update, PSL, PMC PZT investigation 
Message ID: 702     Entry time: Sat Jul 19 19:39:44 2008     In reply to: 701
Author: rob 
Type: Update 
Category: PSL 
Subject: PMC PZT investigation 


The 64k is the series resistor after the PA85, not the modeled resistance of the PZT itself.

Yes. What I meant was that because the measured voltage across the PZT was a half of the open voltage of the HV amp, the DC impedance of the PZT is expected to be similar to the output impedance of the HV amp. Of course, I don't think the DC impedance of a normal PZT should be such low.
I'm puzzled by the discrepancy between this expected DC impedance and the directly measured impedance by the Fluke DVM (1.5M Ohm).
One possibility is that the PZT leaks current only when a high voltage is applied.
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