A rotary encoder is also known as shaft encoder. It is actually an electro-mechanical device that assists in converting the angular position or motion of a shaft or an axle to digital or analog output signals. Rotary Encoders are of two types; that are absolute rotary encoder and incremental rotary encoder.
The current shaft position is indicated the output of an absolute rotary encoder, making it an angle transducer. While the output of an incremental rotary encoder acknowledges about the motion of the shaft, which incorporates information such as position, speed, and distance
Uses of a Rotary Encoder
A rotary encoder has a variety of uses and applications. This includes controlling and monitoring of mechanical system. This includes industrial controls, robotics, photographic lenses, computer input devices such as opto-mechanical mice and trackballs, controlled stress rheometers, and rotating radar platforms.
Types of rotary encoders
As mentioned below, rotary encoders are mainly classified into two types. First one is, Absolute rotary encoder and the second one is incremental rotary encoder.
Absolute Rotary Encoder
Every other position of an absolute encoder is distinct. This means that they have a different code for each shaft position. An absolute rotary encoder defines its position with the help of a static reference point.
Absolute Rotary Encoders functions in situations where accuracy for both speed and position, fail tolerance, and interoperability values higher than system simplicity.
Incremental Rotary Encoder
An incremental rotary encoder is an electro-mechanical device that has only two output signals i.e. A and B. These signals generate pulses when the device is moving. An incremental rotary encoder only shows incremental changes in position and does not report about the absolute position. However, Incremental encoders always deliver an outstanding speed and feedback
How does a rotary encoder works?
A disk is housed in the encoder that has uniformly spaced contact zones. The disk is linked with the Common pin C and other two separate contact pins A and B. so when the disk will start rotating slowly then the common pins A and B will make a contact with the common pin and then the two square will generate signals relatively.
The outputs generated can be used for determining and identifying the rotated position. But if one desires of determining and identifying the rotation direction too, then he must consider both the signals at the same time.
Features of a Rotary Encoder
Some of the major features of a rotary encoder are mentioned below.
- By linking a rotary encoder to a shaft with the help of coupling can assist in controlling and detecting the output directly according to the rotational displacement of the shaft.
- Returning to the origin is not required at startup in case of an absolute rotary encoder.
- It is possible to detect the rotation direction too. The rotation direction is identified by the output timing of phases
- Selecting the optimal sensor that matches the requirements for precision, cost, and connected circuits from a variety lineup of resolutions and output types.