How Does a Rotary Encoder Work?

An electronic device that indicates the shaft’s position or its relative position is called a rotary encoder. There are mainly two types of rotary encoders: the first type indicates the absolute position or the changes in position of the encoder. While on the other hand, the second type of encoder would be where the absolute position output will be, depending upon the manufacturer of the encoder. 

Step-by-Step Instructional Guide

Step 1: Output Channels

The most common type of encoder uses two main output channels, A and B. The two output channels of the encoder assist in indicating the position and the direction of rotation. Suppose, if B leads A, then the disk of the encoder rotates in a clockwise direction. While, if A leads B, then the disk of the encoder rotates in a counter-clockwise direction.

Step 2: Observing the Pulse

You will be able to follow the direction and the position of the rotation by observing both the pulses and the signals of A and B.

Step 3: Third Output Channel

Some of the encoders also include a third output channel which is called an index signal. It helps in supplying a single pulse per revolution, which is used for determining the reference position.

Also, keep in mind that if these encoders are turning fast, then a backward count might be occurring.