Motor Encoder

What is the encoder?

The encoder is a device that compiles signals (such as bit streams) or data and converts them into signal forms that can be used for communication, transmission and storage.

The angular displacement or linear displacement of encoder is converted into electrical signal, the former becomes code wheel, and the latter is called code scale.

Encoders can be divided into contact type and non-contact type according to the reading mode. Contact type uses brush output, and the brush contacts the conductive area or insulation area to indicate whether the code status is "1" or "0".

Non-contact receiving sensitive elements are light sensitive elements or magnetic sensitive elements. When light sensitive elements are used, the state of codes is indicated as "1" or "0" by light transmission areas and opaque areas, and the collected physical signals are converted into electrical signals readable by machine codes for communication, transmission and storage.

Encoder type

According to the working principle, encoders can be divided into incremental and absolute types.

Incremental encoder converts displacement into periodic electrical signal, and then converts this electrical signal into counting pulse, and the number of pulses indicates the displacement.

Each position of the absolute encoder corresponds to a certain digital code, so its indication value is only related to the starting and ending positions of the measurement, and has nothing to do with the intermediate process of the measurement.

The resolution of encoder

The resolution of encoder refers to the number of positions output by one rotation of encoder shaft. Incremental photoelectric encoder is commonly used. Its resolution is also called the number of lines. For example, if 2500 lines are quadrupled, its resolution is 2500*4=10000 pulses.

The higher the resolution of encoder, the smaller the minimum scale of motor, the smaller the angular displacement of motor rotation, and the higher the control accuracy.

Accuracy of encoder

The accuracy of encoder refers to the accuracy of the signal data output by encoder to the measured real angle, and the corresponding parameters are angular minutes and angular seconds.