Pneumatic Actuator Controller Design and Operation

Hydraulic and Pneumatic Knowledge
Fluid Power Equipment

[ Previous Page ] [ Article Start ]

Pneumatic Actuator Controller Design and Operation

The controller generates an output signal that represents the demanded position. This signal is sent to the positioner. Externally, the positioner consists of an input connection for the control signal, a supply air input connection, a supply air output connection, a supply air vent connection, and a feedback linkage. Internally, it contains an intricate network of electrical transducers, air lines, valves, linkages, and necessary adjustments. Other positioners may also provide controls for local valve positioning and gauges to indicate supply air pressure and control air pressure (for pneumatic controllers). From an operators viewpoint, a description of complex internal workings of a positioner is not needed. Therefore, this discussion will be limited to inputs to and outputs from the positioner.

In Figure F2, the controller responds to a deviation of a controlled variable from setpoint and varies the control output signal accordingly to correct the deviation. The control output signal is sent to the positioner, which responds by increasing or decreasing the supply air to the actuator. Positioning of the actuator and control valve is fed back to the positioner through the feedback linkage. When the valve has reached the position demanded by the controller, the positioner stops the change in supply air pressure and holds the valve at the new position. This, in turn, corrects the controlled variables deviation from setpoint.


Figure F2

Next Page - Continue

Related:

Contribute Article Spider Optimizer

© Copyright 2000 - 2017, by Engineers Edge, LLC www.engineersedge.com
All rights reserved
Disclaimer | Feedback | Advertising | Contact

Spider Optimizer

Home
Engineering Book Store
Engineering Forum
Excel App. Downloads
Online Books & Manuals
Engineering News
Engineering Videos
Engineering Calculators
Engineering Toolbox
Engineering Jobs
GD&T Training Geometric Dimensioning Tolerancing
DFM DFA Training
Training Online Engineering
Advertising Center


Copyright Notice

Publishing Program