Basic Principle Of Modulating Electric Actuators
Actuator Modulating Function – Mechanical Shaft Position Feedback
Typically there are 2 methods of monitoring the physical position of the modulating electric actuator’s output shaft, either using a mechanical device, typically a potentiometer driven by a gear connected o the output shaft, or digitally sensing the shaft position. Until recent years the mechanical potentiometer system has been the only choice and generally performs well, but as in any mechanical system there is the potential for failure or wear of the components, and this was a downfall of the use of a potentiometer in the shaft feedback system.
Actuator Modulating Function – Digital Shaft Position Feedback
The more current method of determining the actual output shaft position is by employing digital magnetic position sensing with Hall effect sensors. A magnet is fixed to the modulating actuator’s output shaft and with Hall effect sensors and a digital encoder, the position of the output shaft is very accurately sensed, digitally.
With no moving parts this more modern digital position sensing is both more accurate and less likely to suffer from in service failures when compared to the former mechanical potentiometer
system of shaft position identification.