magneto -
a small dynamo with a secondary winding that produces a high voltage enabling a spark to jump between the poles of a spark plug in a gasoline engine
A magneto is an electrical generator that uses permanent magnets to produce alternating current. Hand-cranked magneto generators were used to provide ringing current in early telephone systems. Magnetos adapted to produce pulses of high voltage are used in the ignition systems of some gasoline-powered internal combustion engines to provide power to the spark plugs.
