Raytheon 138-119, Operator'S And Service Manual

Page: 45 / 55

COMPASS
STD22
Change Over Box
138--119
39
3769DOC000002
Edition: April 06, 2005
6 Error performance
Following considerations will show the reaction in case of a fail of a GG--R system
(Gyro/Gyro redundant) or a GGM--R system (Gyro/Gyro/Magnet redundant) with a con-
nected Change over Box.
These considerations exclude wrong cable connections or broken cable.
At least a GG--R system consist of: At least a GGM--R system consist of:
Gyro 1 Gyro 1
Gyro 2 Gyro 2
Distribution Unit 1 Distribution Unit 1
Distribution Unit 2 Distribution Unit 2
Power Supply 1 Power Supply 1
Power Supply 2 Power Supply 2
Change over Box Magnetic sonde 1
Change over Switch Magnetic sonde 2
Change over Box
Change over Switch
Both Operation Units are not significant to the error performance in this considerations, be-
cause of their function does not effect the redundancy.
The Change over Box is also not significant to the error performance, because of there is
no redundancy in case of their fail.
It is to assume in the following considerations that:
-- The Change over Box operates always with switch position “Automatic”.
It means that in the normal operation mode the outputs of the Distribution Unit 1 are
forwarded via the Change over Box.
Other switch positions (position 1 or position 2) are acceptable only in exceptional
cases.
-- The automatically switch--over function G/G and G/M are always active.
-- Gyro 1 is always the selected sensor.