magneto(n = noun.artifact)magnetoelectric machine - 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 small electric generator with an armature rotating in a magnetic field, having a secondary winding that generates a high voltage, such as one used to generate a voltage sufficient to cause a spark to jump between the poles of a spark plug in an internal-combustion engine. [WordNet 1.5]