Motion feedback devices providing position and velocity information to closed-loop control systems.
Absolute rotary encoders use optical, mechanical, or magnetic indexing for angular measurement. They do not lose their position after power-down, but instead provide absolute position upon power-up without requiring a home cycle or any shaft rotation.
Incremental rotary encoders are multi-turn sensors that use optical, mechanical, or magnetic index-counting for angular measurement. They contain no absolute reference, but instead count relative to the turn-on position.
Linear encoders sense and digitize linear position change for positional measurement and feedback to control systems.
Optical encoder disks and strips are components of rotary and linear encoders, respectively. They are usually made of metal, plastic, glass, or paper. Optical encoder disks and strips have evenly-spaced holes or markings around their perimeter or length.
Rotary position sensors include potentiometers, resolvers and a variety of magnetic and capacitive technologies. Sensors are designed for angular displacement less than one turn or for multiturn displacement.