Hall effect sensor

A Hall effect sensor (also known as a Hall sensor or Hall probe) is any sensor incorporating one or more Hall elements, each of which produce a voltage proportional to one axial component of the magnetic field vector B using the Hall effect (named for physicist Edwin Hall).

Hall sensors are used for proximity sensing, positioning, speed detection, and current sensing applications and are common in industrial and consumer applications. Hundreds of millions of Hall sensor integrated circuits (ICs) are sold each year by ~50 manufacturers, with the global market around a billion dollars.