Introduction
This document lists all the
mission critical systems of Telescope and Instruments Engineering Group. A
system is considered critical when it is required for telescopes or instrument
operation, but a spare part is not readily available.
Scope
Only items that are
maintained by the Telescope and Instruments Engineering Group are included in
this document.
Equipment
|
Item |
Purpose |
Reason |
Location |
Status |
|
FISBA Interferometer |
Flatten NAOMI DM |
Too old, not manufactured anymore. New interferometer system: >45k€ |
GRACE |
No spare |
|
DM (Deformable Mirror) |
AO (Adaptive Optics) cannot be done without
it |
Unique element |
GRACE |
No spare.
A continuous mirror exist in Durham that could be used, but would require
extensive optical, hardware and software redesign |
|
FSM (Fast Steering Mirror) |
AO
Tip-tilt. AO cannot be done without it |
Off-axis paraboloid built to purpose. Expensive |
GRACE |
No spare.
Contact exist in companies Zeiss and Marco |
|
|
GLAS steering mirror system |
Unknown |
GRACE |
No spare.
Would have to be returned to the company |
|
Delay Generator |
Synchronize Pockels cell shutter |
Expensive (€5000) |
GRACE |
No spare |
|
Laser power sensor head |
Measure GLAS laser power |
Unknown |
Laser enclosure |
No spare.
Maybe advantageous for calibration |
|
Notch filter |
Select
laser light for GLAS wavefront sensor |
Extremely expensive and fragile |
GRACE |
No spare |
|
NAOMI return flat mirror |
AO light path |
Extremely expensive and fragile |
GRACE |
Spare received, September 2009 |
|
INGRID IR CCD array |
INGRID sensor |
Not like
other CCDs where there are alternatives |
GRACE |
No spare |
|
ISIS ASL unit |
Reads the linear position transducer of ISIS |
Old system. The spare of the comms
card is broken, it can’t be repaired |
WHT |
No spare |
|
Litton Encoder SBD43-104H30 |
WHT focus 20 bit absolute encoder. Required to focus operation. |
Unknown |
WHT |
No spare |
|
Encoder ITEK RI-17 |
WHT azimuth incremental encoder (Gear) |
Too old,
no longer supported. The spare is in the telescope |
WHT |
No spare.
The old unit have been tried to repair unsuccessfully until now. New spare
encoder from INDUCOTER received (July 2009). |
|
Dome encoder interface box |
Interface
the connection of WHT dome encoder to CAMAC |
Very old.
PCB unique, very bad quality cabling. Drivers in the system are sensitive to
lightning. |
WHT |
No spare.
Very difficult to troubleshoot |
|
DC motor power amplifiers |
Provide
power to motors in rotators (GRACE, GHRIL, PFIP, CASS, cable wrap and focus
drive) |
Not very
robust design. Power transistors need to be screened. Hybrid module not
available anymore. |
6 units at WHT |
No spare
for hybrid module. There are though 4 units at the JKT that could be used as
spare |
|
WHT Nasmyth turret motors |
Tertiary mirror mechanisms. Three-phase motor for parking + one for turntable. If fails may affect CASS and Nasmyth focus |
Documentation inaccurate. |
WHT |
No spare
for motors. No spare for control boards, though possibly they could be
repaired |
|
Motors FEE2/M55 |
Autoguider filter wheel and focus motors |
Unknown |
WHT A&G |
No spare |
|
CAMAC modules ED-011 & ED-013 |
Interface
modules to CAMAC, telescope control system |
Relatively
simple boards made with wire wrapping |
WHT CAMAC |
No spare.
They are going to be duplicated. ED-011
completed. May 2009. ED-013 on
going. November 2009 |
|
|
|
|
|
|
References
Document Location
|
This document is only valid on the day it was printed. http://www.ing.iac.es/~eng/spares/tandi_Critical_Systems.htm |
Revision History
|
|
|
Version number |
Revision date |
Previous revision
date |
Summary of changes |
Changes marked |
|
1.00 |
25 Apr 08 |
N/A |
Document released |
Diego Cano |
|
1.01 |
22 May
08 |
25 Apr 08 |
Document reviewed and
reformatted |
Diego Cano |
|
1.02 |
11 Nov 09 |
22 May 08 |
Update recent spares received |
Diego Cano |
Approvals
|
This document requires the following approvals. |
|
Name |
Signature |
Title |
Date of Issue |
|
René Rutten |
|
Director |
30 Apr 08 |
|
|
|
Head of Operations |
30 Apr 08 |
|
Juan Martínez |
|
Head of Administration |
30 Apr 08 |
|
Don Carlos Abrams |
|
Head of Engineering |
30 Apr 08 |