At 06:51 PM 2/22/2005 -0600, you wrote:

There is an intersting write-up on this site, explaining how the generator, heat sink and diode work on the crankshaft mounted generator for a motorcycle at  http://jerrydoe.com/electrical/chargingsystem.htm   

        Note the brand, "Lucas."

        They are using a shunt regulator. This is no surprise.