Telephone magneto

A telephone magneto, often referred to as a magneto generator, is a device used in early telephone systems to generate a ringing current. It consists of a rotating magnet that passes over coils of wire, inducing an electric current through electromagnetic induction. This current is used to create the ringing signal that alerts the recipient of an incoming call. The magneto is typically hand-cranked, and when operated, it produces a high-voltage alternating current.