An encoder merely is a sensing or communications device that gives feedback. They control an operating devices motion. They can determine the speed and position of a motor or other moving equipment. Encoders convert the motion to an electrical signal which can be read by control devices in motion control systems like counter or PLC. There are different types of Encoder available: Incremental, Rotary, Optical, and Position.

These feedback signals from the encoder can be used to determine the speed, position, or direction. Control devices can use this information by sending a command to a particular function.

We are all aware that all communication devices transmit and receive data through signals, Signals have different current and voltage levels. The amplitudes and magnitudes of the signals always fluctuate and often not precise.

If the amplitude is fractional, first of all, they’ll be rounded up to the upper limit to amplitudes that can be digitally transmitted. Rounding off is done by giving them binary names.

At this point, the encoder is used to take the input of decimal numbers and converting them to binary numbers forming a series of whole numbers like 0 and 1.

The Working Principle of an Encoder

Different technologies are used to create signals from encoders, such as magnetic, resistive, mechanical and optical. Being the most common, optical sensing encoders gives feedback based on the light interruption.

In an optical encoder, through the Code Disk, there’s an emission of light from an LED. The Code Disk has pattered blurred lines like spokes found on a bike’s wheel. With each rotation of the encoder shaft, there’s an interruption of light beams from the LED by opaque lines on the Code Disk before being picked by the Photodetector Assembly.

Consequently, a pulse signal like light = on; no light = off. Signals are sent to the counter or controller, that’ll, in turn, send signals to give the desired function.


Applications of an Encoder

Encoders provide a vital source for an application that requires feedback information. Whether its direction, speed or distance that an application is concerned with them to let users use this information for a specific control.

Due to the emergence of ruggedness, higher resolutions and low costs, encoders are the preferred technology in many areas. Their applications can be found in industrial automation, printers, scientific equipment, and medical scanners.

Encoders are an essential component and can be used in a variety of industries. Below is a partial list where encoders can be applied:

1- Encoders give motion feedbacks to robots on automated assembly lines. The robotic welding arms have the right information in welding the correct locations.

2- In the filling up of jars and bottles, the application provides feedback telling the filling machines the container’s position.

3- In an observatory, encoders tell actuators where the position of a movable mirror is, through the provision of positioning feedback.

4- The military use encoders in the application of positioning antennas.

5- In the industries, encoders are used to label, pack and machine tooling by multi-axis and single motor controllers.

6- Scientific equipment uses encoders by positioning an observatory telescope.

7- Medically, encoders are used in medical scanners, nanosomic motion control of dispensing pumps and automated devices.