What is an encoder?

Encoders come in a variety of configurations, but they all translate phyiscal motion into an electric signal that can be interpreted by a motion control system.
Encoders come in a variety of configurations, but they all translate phyiscal motion into an electric signal that can be interpreted by a motion control system.

Wondering what exactly an encoder is and what it does – or maybe just how to explain these things to someone outside of the motion control industry? In this post we’ll cover some of encoder basics so you can leave with a better understanding, or maybe just a clearer way of describing what an encoder is and what it does.

So, what is an encoder?

An encoder is a sensor that translates physical motion into electrical data. That data can be used to determine the speed, acceleration, direction and position of a mechanical system. Encoders can track two different kinds of motion. Linear encoders track motion in a straight line. Rotary encoders track changes in shaft rotation and are often attached to motors.

While technically speaking, the wire measuring machine shown in the video below is not exactly an encoder, it does give you an idea of how one works. As wire is physically moved from a spool on one side of the machine to a coil on the other, friction moves two wheels in the middle. The rotation of the bottom wheel is used to determine the length of wire, which is displayed on the dials on the front of the device. A rotary encoder could be used to do the same thing, the difference being that the output of the encoder would be a digital signal that could be interpreted by a computer system.

Encoders can be found in all types of machinery in numerous industries, including solar, additive manufacturing (also known as 3D Printing), aerospace, robotics, medical, and textile manufacturing – to name a few. A lot of times, you’ll even find encoders built into motors you buy from electronics parts distributors and catalogs.

Looking for a few examples of how encoders can be used?

  • A 3D printer may use multiple linear encoders to track the position of the print head. The information from the encoders can then be sent back to the motion control system so it can verify that the print head is in the correct position to print the desired object.

  • A delta robot uses a series of motors to control the position of the arms. Some kind of encoder is most likely attached to each motor. The data from each encoder is used to understand the shaft rotation on each motor, which impacts the position of the end effector—the robot’s “hand.”

  • An automated assembly line could use rotary encoders to track motion of a conveyor belt system. With an encoder attached to a motor that moves the belt, the shaft rotation and total revolutions could be used to extrapolate the distance an object on the conveyor traveled.

So, if you are looking to track speed, acceleration, direction or position of a mechanical system, you probably want to take a serious look at encoders.

We offer a wide variety of encoders on our website. If you have any questions, or need help finding the right one for your project, don’t hesitate to contact us. Our customer service and tech support teams are more than happy to spend some time with you via phone or email helping you learn more.


Published in Blog Posts on Tuesday, January 28, 2020