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Encoders: types and characteristics


05.10.2018

Encoders are devices which converts the rotation angle of a rotating shaft into electrical signals, allowing you to determine the angle of rotation of this shaft.
Encoders are used in various industries: engine manufacturing, automation, ceramics and textiles, engineering, etc.

Types of encoders:
1. Incremental encoder
2. Absolute encoder
3. Linear encoder

Incremental Encoders

Incremental encoders are designed to generate pulses, with which the receiving device can determine the current position of the coordinate by calculating the number of pulses by a counter.
In order to bind the reference system to the origin, incremental encoders have reference marks through which equipment pass after the start.

Types of incremental encoder

  • magnetic;
  • optical;
  • with hollow shaft;
  • with a blind shaft;
  • a series of standard and miniature encoders.

What is an optical encoder

Optical encoders are rotation angle sensors, where each position of the shaft corresponds to an individual numbering output code, which, apart from the number of revolutions, is the main working value of the sensor.
Optical sensors have a glass disc with optical raster, rigidly mounted directly on the shaft.

What is a magnetic encoder

Magnetic encoders are sensors the main principles of which are the registration of parameters such as a rotating magnetic element, the passage of magnetic poles and the conversion of these indicators into an appropriate digital code.

Absolute Encoders

In addition to incremental there are absolute rotary encoders. They show the coordinate without requiring the passage of reference marks immediately upon switching on.
With the help of absolute rotation sensors, you can determine the coordinate without moving the axes of the machine.

There are two types of absolute encoders:

  • Single turn - the current coordinate can be determined within one complete shaft revolution.
  • Multi-turn, when the sensors additionally detect several full turns.

The transfer of measured coordinate data by angle sensors and absolute rotation sensors is carried out using electronic interfaces SSI, EnDat, PROFIBUS-DP (others are possible). There are also PROFIBUS-DP, EnDat, SSI bidirectional interfaces that can diagnose and monitor sensors.

Linear Encoders

Linear encoders are sensors or linear converters (transducers) that are tied to the scale, coding position. They track rectilinear offset measurements.
Linear Sensors provide accuracy using the wide range of configurations.

Linear encoder types:

  • absolute potentiometers;
  • magnetostrictive transducers;
  • incremental sensors.

The main encoder product companies are Eltra, Baumer, Sick, Heidenhain, Kubler, Dynapar, Pepperl + Fuchs, Hohner, IFM and others.

Eltra Trade Company provides the best prices for full range of encoders.
We guarantee professional help in choosing the optimal model that meets specific tasks, as well as the high quality of each product.
Call us to find out more information!