Exposure Meter Back-Illumination LED
- Steve Gibson
Table of Contents:
Introduction
This LED is placed above the fiber ends within the Exposure Meter and pointed towards the first lens. The light reflects from the lens surface and returns to back-illuminate the fibers. This allows the science fiber viewing camera in the FIU to determine the location of the exposure meter sky fiber.
Note the Exposure Meter science fiber is also illuminated. Therefore if the scrambler shutters (timed and science source-select) are open then the science fiber will also be illuminated at the FIU when this LED is on.
The LED is turned on and off at the PDU outlet using kpfpower for the appropriate outlet.
Relevant Devices
Descriptions | Qty | Source | Part Number | Notes |
|---|---|---|---|---|
Power Supply | 1 | Tri-Mag, LLC | Tri-Mag PN: L6R12H-120 DigiKey PN: 364-1264-ND | Small-footprint power supply that does not block access to adjacent PDU outlets. |
DC Barrel Extension Cable | 1 | McMaster-Carr | 7332N11 | 15 feet, 18AWG Female-Male |
Icotek Gland | 1 | Icotek | KT11 (41311) or | Unsure which one was installed. |
Barrel Adapter | 1 | McMaster-Carr | 8320N119 | Female-Female adapter, |
Power Adapter | 1 | McMaster-Carr | 8320N117 | Male DC Barrel (5.5 mm OD x 2.1 mm ID) to Terminals |
Green LED | 1 | LW-G-12VDC-K | Has a current-limiting resistor pre-installed for 12V use. |
Relevant Functional Block Diagram
Cable Details
See table and diagram above.
Relevant Datasheets & Manuals
| 1 | Description | File | Source |
| 2 | Power Supply Datasheet |  | https://www.tri-mag.com/wp-content/uploads/2021/05/L6R12H_Series_2021-01.pdf (Linked off the DigiKey product page) |