Magnetoelectric speed sensor |

A magnetoelectric speed sensor is a device that measures rotational speed using the principle of electromagnetic induction. It typically consists of a permanent magnet, a coil, and a rotatable gear (or disk). When the gear rotates, the tooth protrusions cause a change in the air gap, resulting in a change in the magnetic flux through the coil. According to Faraday's law of electromagnetic induction, this changing magnetic flux induces an electromotive force in the coil, the frequency of which is proportional to the gear's rotational speed.