(2)
When a target is in proximity (NEAR) to its sensor, a logic O output produced in the PSEU prox card will be supplied to the PSEU logic card. When a target is out of proximity (FAR) to its sensor, a logic 1 output produced in the prox card will be supplied to the logic card. The logic card converts these inputs singly and in groups into output signals to the driver card. When the input to the driver card is a logic 1, the driver card turns on the associated light and EICAS message. Power of 28v dc supply for the light comes from the master dim and test circuit (Ref 33-16-00)
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MAINTENANCE MANUAL
WALL WELL OUTBD MAIN WHEEL
SEE A SEE B
BRACKET SENSOR
DOOR STOP
FWD A SKIN OUTER BODY SEE C (2 PLACES) SCREWS
TARGET BRACKET SENSOR (RH S10241 SYS 1) (LH S10242 SYS 1) CLOSED SENSOR MAIN GEAR DOOR BRACKET SENSOR
(RH S10072 SYS 2) (LH S10076 SYS 2) CLOSED SENSOR MAIN GEAR DOOR OUTER SKIN MAIN GEAR DOOR DOOR MAIN GEAR DOOR SEAL
B C
Figure 4 MLG Door Proximity Sensors
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MAINTENANCE MANUAL
B A B A
SEE C
SEE B SEE A
FWD
DOOR CLOSED SENSOR A
DOOR CLOSED SENSOR B
Nose Gear Proximity Sensors Figure 5 (Sheet 1)
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MAINTENANCE MANUAL
NOSE GEAR DOWN SENSOR (DOWN POSITION SHOWN)A-A B-B
Nose Gear Proximity Sensors Figure 5 (Sheet 2)
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MAINTENANCE MANUAL
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ALL ú ú 01 Page 11 ú Jan 28/02
A
B
C
D
E
F
G
HIJKLM
PROXIMITY SWITCH ELEX UNIT (PSEU)
SENSOR TARGET FAR
Landing Gear Position Indicating and Warning SchematicFigure 6 (Sheet 1)
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B
C
D
E
F
G
HIJKLM WITH THE -512 EICASRELAY
Landing Gear Position Indicating and Warning SchematicFigure 6 (Sheet 2)
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MAINTENANCE MANUAL
(3)
The sensor and logic circuits perform three essentially independent functions in deciding landing gear status. The gear down and warning circuits decide whether the gear is down and locked, up and locked, or in transit. They turn on three green NOSE, LEFT and RIGHT lights when all gears are down and locked. They turn on the amber GEAR light (and EICAS messages) when the gear is in transit, or there is disagreement between gear positions or between gear and lever positons. Lever position (down or not down) signal comes from two MICRO switches on the gear lever. The amber DOORS light and GEAR DOORS EICAS message come on when any gear door is open. If all gears are up and locked, all gear and lever positions agree, and all gear doors closed, the following lights and messages will be off:
(a)
LEFT light
(b)
RIGHT light
(c)
DOORS light
(d)
GEAR light
(e)
GEAR DISAGREE message
(f)
GEAR DOORS message
(g)
LDG GEAR MONITOR message
(h)
PSEU BITE message
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FAULT ISOLATION/MAINT MANUAL
LANDING GEAR POSITION INDICATION AND WARNING SYSTEM
COMPONENT FIG. 102 SHT QTY ACCESS/AREA REFERENCE
CIRCUIT BREAKERS - 1 FLT COMPT, P11
LANDING GEAR POS SYS 1, C1175 1 11C30 *
LANDING GEAR POS SYS 2, C4279 1 11S23 *
COMPUTERS - (31-41-00/101) LANDING GEAR POS SYS 2 ALTN, C4478 EICAS R, M10182 EICAS L, M10181 1 11C19 *
LIGHTS - INDICATION, DOORS, L396 1 1 FLT COMPT, P3 *
LIGHTS - INDICATION, GEAR, L397 1 1 FLT COMPT, P3 *
LIGHTS - INDICATION LEFT, L400 1 1 FLT COMPT, P3 *
LIGHTS - INDICATION, MOSE, L398 1 1 FLT COMPT, P3 *
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