ENCODER

An incremental rotary encoder also known as a relative rotary encoder or a quadrature encoder, has two outputs called quadrate outputs. They can be either mechanical or optical. In the optical type there are two gray coded tracks, while in mechanical there are two contacts that are actuated by cams on the rotating shaft. The mechanical types requires debouncing and are typically used as digital potentiometers on equipment including consumer devices. Most modern home and car stereos use mechanical rotary encoder for volume. Due to the fact the mechanical switches require debouncing, the mechanical type are limited in the rotational speeds they can handle. The incremental rotary encoder is the most widely used of all rotary encoder due to its low cost.