Manual 04176
ProAct II Actuator/Driver
Woodward
19
A 25-turn pot (Position Command Offset) adjusts the offset of the actuator travel
when the speed control signal varies from minimum to maximum.
A 25-turn pot (System Position Feedback Gain) adjusts the system position
feedback gain as the actuator varies from minimum to maximum.
A 25-turn pot (System Position Feedback Offset) adjusts the system position
feedback offset as the actuator varies from minimum to maximum.
Actuator Position Signal
The feedback device is located on the closed shaft of the actuator. The older
actuators use a rotary transducer which changes resistance proportional to the
actuator shaft angle. The new replacement actuators use a rotary Hall Effect
position sensor which changes output voltage proportional to the actuator shaft
angle. The device is a non-contacting unit, thereby eliminating most wear
problems.
Actuator
The rotary design of the ProAct actuators gives 75 degrees of shaft rotation to
position fuel controls. The actuators apply torque in both directions. Torque is
proportional to the current supplied to the actuator by the driver.
The actuator uses sealed bearings, eliminating the need for maintenance. The
feedback mechanism attaches to the end of the rotor not being used to control
the engine. The device is enclosed in a Ryton housing and is sealed against the
elements. Avoid pressure washing the actuator.
An inertia disc is installed on the actuator output shaft. The disc is necessary for
stable actuator operation with light, low-friction linkages. Do not remove the disc
(see Figure 1-3).
