A Hall Effect sensor is a transducer that converts a changing magnetic field into a change in output voltage. Hall sensors are used to measure magnetic fields, as well as physical quantities that generate and affect magnetic fields, such as in proximity switches, Hall, position measurement, speed measurement and current measurement devices. In its simplest form, the sensor acts as an analog transducer and returns a voltage directly. With a known magnetic field, its distance from the Hall disk can be set. Using multiple sets of sensors, the relative position of the magnets can be inferred. The current passing through the conductor produces a magnetic field that changes with the current, and Hall-effect sensors can measure the current without disturbing the current, typically by integrating it with a winding core or a permanent magnet next to the conductor being measured .