Comment by hydrogen7800

5 days ago

Yeah, it was a potentiometer. Is an encoder not simply any device that provides a signal proportional to its position or displacement? It had wiper arms (brushes?) that dragged along a conducting surface on a PCB below the rotor.

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.