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Mon Oct 14 17:01:43 2019, anchal, Notes, Laser, South Laser Switched Off!
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Mon Oct 14 18:30:14 2019, anchal, Notes, PMC, South PMC Error Signal Oscillations
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Tue Oct 15 18:54:16 2019, anchal, Notes, PMC, South PMC further problems
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Wed Oct 16 16:56:43 2019, anchal, Notes, PMC, South PMC won't work with it's own Servo Card only
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Wed Oct 16 17:33:08 2019, Koji, Notes, PMC, South PMC won't work with it's own Servo Card only
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Wed Oct 16 18:46:58 2019, anchal, Notes, PMC, South PMC started working somehow :(
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Wed Oct 23 17:39:44 2019, anchal, Notes, PMC, South PMC started working somehow :(
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Fri Oct 25 16:50:12 2019, anchal, Notes, PMC, South PMC problem debugging efforts
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Tue Oct 29 19:10:59 2019, anchal, Notes, PMC, South PMC problem debugging efforts
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Wed Oct 30 15:15:28 2019, anchal, Notes, PMC, Replacing U5A AD602 didn't solve the issue.
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Wed Oct 30 18:35:31 2019, anchal, Notes, PMC, Issue closed
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Mon Nov 4 12:15:01 2019, anchal, Notes, PMC, Changing the autolocking method
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Message ID: 2452
Entry time: Mon Oct 14 18:30:14 2019
In reply to: 2451
Reply to this: 2455
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Author: |
anchal |
Type: |
Notes |
Category: |
PMC |
Subject: |
South PMC Error Signal Oscillations |
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South PMC Error signal is showing huge weird capacitor charging type oscillations. Attached is an oscilloscope measurement of it. A more weird thing is that this peak is appearing at random frequencies, that is, if I take single sequence measurements of 1 ms length, I see these peaks occurring at a difference from 100 us to 500 us, randomly.
Changes:
- I had to re-adjust the power going to the PMC to get 9.6mW power falling on the cavities. But I think the knob was more or less in same place.
- I had to restart whole lab (all channels and scripts) as I suspected some channels are not responsive.
- I can't increase the fast gain on southside beyond -7 dB (while this was 14 dB before). so this SPMC oscillations are really hindering badly.
- I also suspect that the NPRO temperature control is not as stable as before on the south side, probably because it was switched off for more than 2 days.
- I'm hoping by tomorrow, this should get better. but still need to investigate the issue on south PMC.
Data |
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