Machines must be correct in their work. A small mistake can stop the line or spoil the product. To avoid such problems, industries use some tools which show the position and movement of parts. One such tool is called an absolute encoder. If this word looks new to you, don’t worry. Let us understand it in very easy language.

What Is an Absolute Encoder?

An absolute encoder is a sensor. It gives the exact position of a shaft, motor, or any moving part. Normal sensors can only show movement, but this one gives the real position at every moment. Even if the machine is switched off and then started again, the encoder remembers the last position. For this reason, many factories use it where accuracy and safety are important.

How Absolute Encoders Work

Inside the encoder, there is a small disc. This disc has many marks or codes. When light or magnetic signals pass over these marks, the sensor reads them. After that, the signals go to the machine in digital form. Now the system knows the correct position of the rotating shaft.

In short, it does not only tell how much a part moved, but also where exactly it is. That makes it different from other sensors.

Types of Absolute Encoders

There are two main types of absolute encoders – single-turn and multi-turn. Apart from this, encoders are also made with different technologies such as optical, magnetic, capacitive, and inductive.

Single-turn type: It works within one full rotation of the shaft. After one turn, the value repeats. It is used where only one round is enough to measure position.

Multi-turn type: Multi-turn absolute encoders track both the shaft's angular position (0-360 degrees) and the number of full 360-degree revolutions it has completed.

Advantages of Absolute Encoders

  • No need of battery backup because position data is not lost.
  • Can perform many functions such as scaling, speed control, preset, and also Fieldbus.
  • Works with magnetic or optical scanning for measurement.
  • Even after power cut, it can still give the correct position.
  • Programming is flexible and easy to adjust as per need.
  • Supports many interfaces like Ethernet, Analog, Serial, Parallel, and Fieldbus.
  • High precision makes it suitable for applications where safety is important.
  • Can always tell the exact position of the machine parts.

Limitations of Absolute Encoders

Even though these encoders are useful, there are some limits.

  • The price is higher compared to normal encoders.
  • And most importantly, setting them up is not always simple, and sometimes extra care is needed.
  • In places with dust, dirt, or too much vibration, the working may be reduced.

Applications of Absolute Encoders 

Absolute encoders are used in many areas where machines need position control or movement monitoring. Some common uses are:

  • Surgical robotics
  • Microelectronics
  • Diagnostic imaging
  • Photonics
  • Radiation therapy
  • Industrial robotics
  • Satellite communications
  • ROVs & UAVs

Choosing the Right Absolute Encoder

Before buying, it is better to check your requirements. For simple jobs where only one rotation matters, a single-turn encoder is enough. For jobs with many turns, multi-turn encode would be a great choice. Also you should look at the environment, level of accuracy needed, and your budget.

Conclusion

Absolute encoders are important tools in modern machines. Because it gives correct position data, increases safety, and reduces mistakes. Even though the cost is more, the benefits make them useful for many industries.

So, if you want smooth working and reliable output, absolute encoders are a good choice.