Hi Ed :
Well, it's not the regulator that gets polarized, but it's not an old wive's
tale either.
When you first start the engine, the cutout relay in the control box is
still open, because the output voltage from the generator is still almost 0,
because it's field current is 0. However, there is enough residual
magnetism left in the housing and field pieces to generate just a little bit
of voltage. The control box directs that voltage into the field windings,
which increases the output voltage, which increases the field current, and
the output voltage quickly rises to where the cutout closes. But, the
residual magnetism has to be present, and has to be the proper polarity.
That's what the 'polarizing' does, is magnetize the housing and field pieces
to the proper magnetic polarity.
Now if the generator has been previously polarized with the opposite
polarity, it will still start up as above, but in the wrong direction !
Now, when the cutout closes, it's connecting the -12v from the generator to
the +12v of the battery. A fair amount of electrical violence ensues, but
the cutout contacts and generator _usually_ survive.
Randall
>
> The logic of "polarizing the voltage regulator" when changing from + to -
> ground escapes me.
>
> Anyone care to explain? Sounds like another old wives tail to me.
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