permanent-magnet generator mainly employed for ignition (ignition system) of compressed gasses in internal combustion engines (internal-combustion engine). Primary applications have been in small aircraft, marine, tractor, and motorcycle engines, which may not have an available battery supply. The major parts of the magneto are a permanent-magnet rotor, an armature with a primary winding containing a small number of turns, a parallel-connected capacitor, a secondary winding with a large number of turns, and a cam-type circuit breaker. As the magnetic rotor is turned, it induces a current in the primary winding. The cam breaks the circuit when the induced current is near its peak. The rapid change of magnetic field causes a high voltage to be induced in the secondary winding. This is distributed to the spark plugs for ignition.