All rotary encoders consist of a light source, light detector, code wheel, and signal processor. There are two basic encoder styles: absolute and incremental.

The video is a primer on encoder design, walking you through the basics of sensing rotation with phototransistors, and how a pair of detectors is needed to determine the direction of rotation.

(See Figure 1.) Figure 1 Encoder Basics The old analog modulator takes in one source, typically baseband audio and video, and creates an analog carrier for those signals to ride on. Composite Video, ...

Rotary encoders track motor shaft movement for myriad pieces of industrial equipment and commercial devices. For industrial applications, incremental encoders (used when only relative position is ...