Comment by HeyLaughingBoy

5 days ago

An encoder is a device that encodes the position -- absolute or relative -- of its shaft as a set of digital outputs.

Most common type uses optical sensors internally, although there are also magnetic types. A quadrature encoder is the most popular and provides two output signals, phase separated by 90 degrees. The phase separation allows the reader to determine which direction the shaft is moving.

A potentiometer used for position feedback is usually just called a potentiometer. I guess it's technically an encoder, but I don't think I've ever heard it referred to that way.

There are also resolvers, discussed somewhere else in this thread, but we won't go there!

HTH

> A potentiometer used for position feedback is usually just called a potentiometer. I guess it's technically an encoder, but I don't think I've ever heard it referred to that way.

I have absolutely seen potentiometers called encoders in industrial applications. The underlaying technology is irrelevant. Encoders and revolvers are just transducers of position.