产品说明
The ProAct III and ProAct IV drivers convert either a 0–200 mA or 4–20 mA control signal from a Woodward electronic control into a specific actuator position.
The ProAct drivers require a separate electrical supply of 20–32 Vdc. The supply must be capable of supplying a sustained 10 A and a peak 20 A for up to two seconds for both the ProAct III and ProAct IV drivers.
The ProAct III actuator provides up to 14 J (10 ft-lb) of work to move the fuel setting lever on the engine. The ProAct IV actuator provides up to 27 J (20 ft-lb) of work. The actuators rotate 75 degrees, and they have position feedback.
Figures 1-1 through 1-3 show the control outline drawings, and Figure 1-4 is the plant wiring diagram.
Engine stability and response are set by the controlling device, not by the actuator and driver. Follow the instructions for the controlling device while setting up the engine control system.
A 25-turn potentiometer (Offset) adjusts the actuator position with a minimum input signal from the speed control.
A 25-turn pot (Span) adjusts how far the actuator travels when the speed control signal varies from minimum to maximum. This pot adjusts the maximum position of the actuator. The Span adjustment range is approximately 40 degrees to 75 degrees.
The Span and Offset adjustments are interrelated. The adjustments may need to be repeated until the desired actuator travel is achieved. A one-turn pot (ACT. BANDWIDTH) adjusts how quickly the actuator responds to a change in signal from the speed control (bandwidth 2–9 Hz).
4–20 mA Output Models
Units which provide a 4–20 mA output proportional to actuator position have two additional 25-turn potentiometers (Position Span and Position Offset). These potentiometers adjust the 4–20 mA output to correspond to minimum and maximum positions of the actuator. The Position Offset adjusts the output at minimum position to be 4 mA. The Position Span adjusts how much the output changes with a given actuator position change and is used to adjust the maximum output current. The adjustments are interrelated and may need to be repeated until the desired output is achieved.
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. The feedback voltage is approximately 2 Vdc at 0° and 3 Vdc at 75° (measured from 0 to –, which is white to black sensor wire for conduit or MS connector terminals C and E; see Figure 1-4).