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Entry  Fri Dec 10 10:33:46 2010, Zach, Laser, GYRO, update 
    Reply  Fri Dec 10 13:43:07 2010, Koji, Laser, GYRO, update 
Message ID: 1208     Entry time: Fri Dec 10 13:43:07 2010     In reply to: 1203
Author: Koji 
Type: Laser 
Category: GYRO 
Subject: update 

We need some bias to the PZT out.

> 5. I found that if the PZT output goes to negative on the oscilloscope,
> the gyro signal have larger noise than usual. I put an offset to the slow servo
> such that it does not go into the negative side.


I noticed that there was a (slow) error signal offset of about 4000 cts. Koji had recently put in a manual offset of the same amount to counteract what was an offset in the other direction before. I turned this off and was able to get the error signal back to around 0 by clearing the servo memory (i.e. just turning the filter block off and on and then reengaging the output).


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