Ks 271C Roll Servo - Honeywell BENDIX/KING KAP 140 Maintenance Manual

1.5.5 KS 271C ROLL SERVO

The KS 271C roll primary servo actuator is used in the roll axis to provide AFCS control of the
aircraft ailerons. It contains a servo motor with amplifier and engage clutch solenoid. The roll servo
is installed with a KM 275 servo mount, which contains a slip clutch for pilot override. The servo
receives a differential command input and drives the servo motor with a speed proportional to the
magnitude of the command. The command polarity will determine direction of servo rotation. The
command inputs have an impedance of at least 15K ohms. The interface is designed such that
an open command signal will not cause a servo drive of more than 25% of full--scale speed.
The roll servo also contains a validity circuit which compares the motor voltage against the servo
command. The servo actuator outputs a open/ground discrete signal, where ground represents
a valid servo. If the comparison fails, the servo outputs an invalid (open) signal to the FCC.
Removing power to the servo (e.g. by pressing the AP DISC switch)
will also cause the servo to be sensed as invalid.
Revision 2, Dec/2002
CS:15574F02.IDU
BENDIX/KING
KAP 140
NOTE
FIGURE 1--4 KS 271C ROLL SERVO
Page 1--10