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Message ID: 1695     Entry time: Mon Aug 1 19:05:15 2016
Author: awade 
Type: Notes 
Category: Electronics Equipment 
Subject: South path voltages and box move 

Notes on voltage settings of the two PDH control loops.

I was examining how I would move the south path control front-end box over to the rack (it is presently under the south side of the table). I noticed that the voltage on the 17 V lines was set to +/- 23.2 V and that the 24V input lines were set to +24.0V and -27.6V for their positive and negative lines.  I'm not sure if there is a reason for this, i.e. whether the south setup requires a greater voltage overhead.  I have turned the voltages down 17 V and 24V for the respective south path power supplies for now to be safe. Also, the HV lines for the south PDH loop were set to 139.4 V and -133.4 V, this sounds OK to me, as long as there are no PZTs being drive to that negative voltage.

Also, the PD on the south path is powered at +14.96/-15.53 V (pulling +39 mA/-18 mA), the north path is set to +16.81V/-16.71 (pulling +78 mA/-50 mA). I'll have a look back through the eLog to see what their speced voltages are and whether they should be the same.

I have not moved the box yet. 

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