Alternator Q's

[Chuck Ciaffone <chuckc@ibm.net>]

Please explain how alternator voltage regulators work.

My Lucas has one wire (+ 1 wire for the idiot light).
That wire goes both into the battery and into the
wiring harness.

Now I assume that while running I'm driving off the
alternatator. So the alternatator produces electricity
continually.

When the battery is back up to full charge (as after starting)
how does that 1 wire continually provide juice to the
harness while NOT continuing to charge the battery?

I ask this because I seem to be over charging the battery.

chuck