Manual 04176
ProAct II Actuator/Driver
Woodward
23
Actuator compliance
The actuator compliance will be to reach peak steady-state torque in less than
5% of actuator full travel, external deflection of the actuator from commanded
position for all supply voltages and current levels within the specified power
supply ranges.
Actuator slew rate
The actuator slew rate will be between 80 ms and 100 ms for a 10% to 90% or
90% to 10% actuator slew, commanded with the appropriate input square wave
for all supply voltages, current levels and inertial loads within the specified
ranges.
Small signal bandwidth
The small signal (1% of full stroke actuator travel sine wave actuator drive)
bandwidth of the driver for command to position will be between 6 and 8 Hz for
the –3 dB point and 3 and 4 Hz for –45 degree phase loss point, for all supply
voltages, current levels, and actuator load inertias within the specified ranges.
Large signal bandwidth
The large signal (10% of full stroke actuator travel sine wave actuator drive)
bandwidth of the driver for command to position will be between 10 and 15 Hz for
the –3 dB point and between 4 and 5 Hz for the –45 degree phase loss point, for
all supply voltages, current levels, and actuator load inertias within the specified
ranges.
Position accuracy
The position accuracy for command to position will be better than 1% of actuator
full travel after the unit has been calibrated to the actuator for gain and offset.
This accuracy is valid at the calibration temperature of the actuator assembly. If
the actuator assembly temperature is different from the calibration temperature,
the position error will be less than 20% over the entire temperature range. The
temperature deviation is a negative tolerance. This means that the unit will drift
such that minimum fuel and maximum fuel is always reachable using the
standard input range. However, the unit may reach minimum or maximum fuel at
input percentages 20% less than (in the case of maximum fuel) or greater than
(in the case of minimum fuel) the nominal range.
Unit-to-unit position accuracy
The unit-to-unit position accuracy for two units that have been calibrated and are
mounted on the same engine, operating from the same command signal and at
the same temperature, will be less than 5% for all actuator temperatures within
the specified operating range.
System protection
The system contains protection circuitry to prevent damage if the power supply
circuits are connected in reverse polarity. The unit also contains circuitry to
prevent driver and actuator damage if one of the actuator wires is short-circuited
to battery positive or ground, or if one actuator wire is shorted to the other. The
result will be an actuator shutdown during the period of the short circuit. The unit
also contains circuitry to prevent driver and actuator damage if the driver steady-
state current rises above 6 A continuously. The result will be an actuator
shutdown.
