aLIGO ISS Outer Loop Back Board

Document #:

LIGO-D1600298-v4

Document type:

D - Drawings

Abstract:

This is the board with the servo electronics, and signal conditioning in the ISS Outer Loop Servo Chassis

Files in Document:

• pdf of schematic and pcb (D1600298-v4.pdf, file is not accessible)

ICS/JIRA Record:

• ICS_LINK

Topics:

• Laser Systems

Authors:

• Benjamin Abbott

Notes and Changes:

Changes:
- Connect feedback of open OpAmp U2B to negative input and ground the positive input.
- Increase the gain of the sum by increasing R32 to 10K (from 1K).
- Swapped the corresponding OpAmp U3 from OP27 to OP37.
- Decrease the gain by 10 in the readback of ERR2 after the sum by changing R62 in the SUM signal block from 4.53K to 45.3K.
- Decreased the analog excitation input gain by 10 by increasing R33 to 100K (from 10K).
- Decreased the digitla excitation input gain by 10 by increasing R77 to 100K (from 10K).
- Switch error signal Err1Mon readback to before servo loop switch.

Referenced by:

• LIGO-D1600229-v1: aLIGO Outer Loop ISS Chassis