Economical flywheel alternator for trickle charging a small lawnmower battery

In an ignition system for an internal combustion engine having a flywheel, a flywheel supported magnetic member comprising a single tangentially poled permanent magnet and a three legged E-shaped stator core with the three leg ends disposed closely adjacent the outer periphery of the flywheel to be magnetically coupled in pairs once furing each revolution of the flywheel by the magnetic member as the magnetic member rotates past the core wherein the three stator core legs are generally coplanar and extend generally parallel to one another with the angle subtended by adjacent "E" legs relative to the flywheel axis being substantially the same as the angular extent of the magnetic member, the improvement comprising a fourth stator core leg having one end closely adjacent the flywheel with the angle subtended by the fourth leg and the adjacent outer leg of the "E" relative to the flywheel axis being substantially the same as the angular extent of the magnetic member, a low voltage coil surrounding the fourth leg, a capacitor connected in parallel with the low voltage coil, storage battery means utilizing electrical energy induced in the low voltage coil by passage of the magnetic member and a rectifier in series with the parallel combination of the low voltage coil and capacitor comprising a diode for conveying a single primary charging pulse to the battery during each revolution of the flywheel to trickle charge the storage battery means.