Raytheon 138-119, Operator'S And Service Manual

Page: 15 / 55

COMPASS
STD22
Change Over Box
138--119
9
3769DOC000002
Edition: April 06, 2005
2.1.2 Switch position “System 1”
If the Change Over Switch is switched into position “Sys 1” manually, the signal outputs of
the compass system 1 are carried out of the Distribution Box via the Switch Over Box
(see Figure 4).
The connection of the relay “System Failure” of system 1 (DU 1) via the Change Over
Switch is not used. The 24 V DC potential is not switched to the relays of the Change Over
Box. All relays are dropped out.
ATTENTION!
There is no automatic switch--over to DU 2 if the
DU1 fails (”System Failure”).
The Change Over Box does not switch signals
from the outputs of the Distribution Unit 1 to the
heading receivers.
2.1.3 Switch position “System 2”
If the Change Over Switch is switched into position “Sys 2” manually, the signal outputs of
the compass system 2 are carried out of the Distribution Box via the Switch Over Box
(see Figure 4).The connection of the relay “System Failure” of system 2 (DU 2) via the
Change Over Switch is not used. The 24 V DC potential is fed from the Change Over Box
via the Change Over Switch and back again to the Change Over Box. All relays operate.
ATTENTION!
There is no automatic switch--over to DU 1 if the
DU2 fails (”System Failure”).
The Change Over Box does not switch signals
from the outputs of the Distribution Unit 2 to the
heading receivers.