Rotary encoder with absolute readout offers high resolution and low cost

摘要

Rotary encoders are typically used in positioning systems with servo feedback in which the cost of the encoder usually is of minor importance. Encoders, however, are also used in user interfaces to encode the positions of knobs—the volume knob on an audio system, for example. For those knobs, you have the choice between either a potentiometer boasting low cost, high resolution, and absolute readout but only limited travel-typically less than 340°-or a mechanical-optical rotary encoder, which has endless travel but a higher cost, low resolution, and only relative readout.