K04502
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH 10-62253 YAW DAMPER ú

 22-12-01
 COUPLER  ú
 ú 01 ú BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.  Page 4Jul 12/99 

A 737-300/400/500MAINTENANCE MANUAL
 2.  Yaw Damper Coupler
__________________
 A.  The yaw damper coupler provides rudder deflection commands to compensate for movement about the yaw axis.
 B.  The yaw damper coupler is installed on the E1-3 shelf of the electronic equipment racks in the electrical and electronics compartment.
 C.  The yaw damper coupler is a rack-mounted assembly containing solid state components that include rate sensors, a power supply, a processor and I/O card assembly, and a BITE control/display module.
 D.  The front panel of the coupler contains a placard that shows BITE operation instructions, and a BITE control/display module. The control module has six pushbuttons and a 2-line alphanumeric display. Each line has eight seven-segment LEDs.
 3.  Yaw Damper Engage Switch
________________________
 A.  The yaw damper engage switch is used to place the yaw damper system in the operating mode.
 B.  The yaw damper engage switch is a 2-position solenoid-held switch. The solenoid is controlled by the yaw damper engage logic and holds the switch in the ON position.
 4.  Disengage Warning Light
_______________________
 A.  The yaw damper disengage warning light indicates that the system is not engaged in the operating mode.
 B.  The disengage warning light is an amber annunciator that illuminates whenever the yaw damper is not engaged. The master caution lights and the flight control master caution annunciator lights, located on the glareshield, also illuminate when the disengage warning light comes on.
 5.  Yaw Damper Rudder Position Indicator
____________________________________
 A.  The yaw damper rudder position indicator displays rudder movement caused by yaw damper coupler commands.
 B.  Whenever the yaw damper system is engaged, the yaw damper position indicator reflects the movements of the yaw damper actuator. The position transducer on the rudder power control unit senses actuator displacement from neutral and provides a signal to the yaw damper coupler. The yaw damper coupler provides a signal to the indicator that is proportional to the rudder displacement from the yaw damper actuator.
 6.  Rudder Position Transducer
__________________________
 A.  A linear variable differential transformer (LVDT) mounted in the rudder power control unit supplies a rudder position feedback signal to the yaw damper coupler. The LVDT is a variable reluctance transformer which is excited by 26 volts ac. The magnitude of the output signal varies directly with the length of the input stroke and the phase of the signal changes with the direction of the stroke from the center null position.
 7.  Rudder Transfer and Solenoid Valves
___________________________________
 A.  The engage solenoid and the transfer valve control hydraulic flow for yaw damper control of the rudder power control unit.
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH 10-62253 YAW DAMPER ú

 22-12-01
 COUPLER  ú
 ú 02 ú BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.  Page 5Mar 15/99 

A
737-300/400/500MAINTENANCE MANUAL
 B.  The yaw damper engage solenoid is mounted on the rudder power control unit. It is a solenoid actuated valve which is energized when the yaw damper is engaged. It then supplies hydraulic power to the transfer valve.
 C.  The transfer valve, also mounted on the rudder power control unit, converts the yaw damper electrical signals into hydraulic flow to move the rudder. The unit consists of a torque motor which moves a jet pipe assembly that regulates the hydraulic flow to the control valve.
 8.  Rudder Pressure Reducer System______________________________
　
中國航空網(wǎng) www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：737-300 400 500 AMM 飛機維護手冊 自動飛行 AUTOFLIGHT 2(80)