SYSTEM FUNCTIONAL DESCRIPTION (cont)
(l) The lampholder assembly contains a lamp which is used for alinement of
the dayside test bench inner module during calibration.
(m) The automatic focus control assembly is located in the optic path
between the filter wheel/motor assembly and the UUT.
The computer positions the auto-
matic focus control assembly to compensate for slight changes in focal path length due
to temperature changes within the inner module.
Focus adjustments are based on type
of tests to be performed, and on the spectral range in use.
The nominal is for the
direct view optics spectrum and then adjustments are made for the TV spectrum, and the
laser spectrum, and in every case for temperature shifts.
(n) The beam sampler assembly is located in front of the radiometer narrow
beam attenuator; a part of the radiometer assembly.
The beam sampler is an optical
transferring device made up of a base and housing, two optical beam splitter lenses,
and a protective cover.
The purpose of the beam sampler is to split the laser beam
path into two separate paths.
One path is through the laser port inside the laser
cover assembly and the other path is down through the filter wheel/motor assembly.
(o) The laser cover assembly forms part of the laser interlock circuit to
prevent firing of the laser transceiver unit UUT without an enclosed shielded environ-
Two door interlock switches and a key switch are part of the laser interlock
circuit which must be enabled before the laser can be fired.
(3) Indirect View Display 2A1A3.
The IVD is an electronic assembly located in
in the rear of the dayside test bench.
It is used to test the airborne IVD and the
The dayside test bench IVD is identical to its airborne counterpart, except
it does not contain five CCAS installed in the airborne IVD.
(4) Laser Power Supply Assembly 2A1A6.
The laser power supply assembly is locat-
ed in the rear of the dayside test bench.
It receives 115 vat, 400 Hz 3-phase voltage
from the major test adapter and returns 1000 vdc.
It also receives +28 vdc from the
major test adapter and returns 600 vdc.
(5) Laser Power Meter 2A1A7 and Radiometer Head 2A1A8. The laser power meter and
radiometer head form a portable system used to measure the output of the laser tracker
unit and laser transceiver UUTS.
d. TEST CONSOLE TEST BENCH 2A2
(1) Programmable Digitizer 2A2A1.
The programmable digitizer 2A2A1 is used to
digitize video (analog) inputs, which are accepted under program control by two
(a) Analog to digital conversion is performed by two special electron-
bombarded semiconductor (EBS) tubes (one per channel).
(b) A signal from programmable pulse generator (PPG) #2 CCA in the elec-
tronics drawer assembly 2A2A7 is used to set trigger parameters on the basis of front
panel input or commands received on the IEEE 488 bus.