Sandia Aerospace SA 3NVG - Manual (Page 16)

3.3.5 SR 34 12 Pole Switching Module
The SR 34 provides 12 poles of switching through three, hermetically sealed, bifurcated re-
lays. The relays contacts are gold plated and have a 2 amp resistive load rating at 28 VDC.
Coil current is 60 mA. Both the SR 34 and SR 64 use the same circuit card. Each relay is
independently switched through their appropriate coil pins.
See figure 3-7 for a schematic and pinout of the SR 34
3.3.6 SR 54 20 Pole Switching Module
3.3.7 SR 64 24 Pole Switching Module
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The SR 54 provides 20 poles of switching through five, hermetically sealed, bifurcated re-
lays. The SR 54 has a built in circuit that swithces all relays to their de-energized conditon
whenever K6 is activated. This can be used for such applications as insuring LOC is present-
ed on the HSI whenever a LOC signal is selected. The relays contacts are gold plated and
have a 2 amp resistive load rating at 28 VDC. Coil current is 120 mA.
See figure 3-8 for a schematic and pinout of the SR 54
The SR 64 provides 24 poles of switching through six, hermetically sealed, bifurcated relays.
The relays contacts are gold plated and have a 2 amp resistive load rating at 28 VDC. Coil
current is 120 mA. K1, K2, K3 and K4 are switched simultaneoulsy through coil pins, 71
and 72. K5 and K6 are independently switched through their coil pins.
See figure 3-7 for a schematic and pinout of the SR 64
CAUTION
Since all pins on the SR 34, SR 54 and SR 64 are used for switching func-
tions, there is NO KEYING PIN. Cautions must be taken when reattaching
the connector to insure that it is going to the correct devise. Failure to do
so may result in board damage.
3.3.4 SA 24 Diode Isolation/Test Module
The SA 24 provides 23 lines of diode isolation. The SA 24 also provides a test input for
testing annunciators. The test input can be either a high or a low. Pin 48 on the SA 24 is the
keying pin and has been removed at the factory. A plug which is supplied with the installa-
tion kit must be inserted into Pin 48 of the mating connector.