LM317T Voltage Regulator with Pass Transistor

The magneto alternator of Royal Enfield Motorcycle UCE EFI G5 has 18 coil 3 phase stator that charges 12 volt battery. The alternator electric output is directly affected by the speed of motorcycle engine (rpm). Alternator generated AC of 15 volts when engine was running at idle and it increased to 40 volts as throttle was opened to high rpms.



http://www.youtube.com/watch?v=p6GnwkCXPi4&hl=en