To add one tiny bit to Trevor's response, below...
Think of the "ground" on your (or any) car as a "common," as in common
electrical connecting buss. Whether it is positive or negative wouldn't
really matter, except that some components are "polarized" *and* use
their mounting points as a method of grounding. This is where the
trouble comes in with regard to positive vs. negative grounded vehicles.
-Schuyler
Trevor Boicey wrote:
> Jerry McDonald wrote:
> > I'm taking a class on electrical troubleshooting for work. The
> instructor
> > asks which direction does electricity flow pos to neg or neg to pos?
> In my
> > ignorance I pipe up with "both".
>
> In actuality you were somewhat right.
>
> Electrons flow one way (from negative to positive). The "holes", or
> abscense of electrons, flow the other way.
>
> This is meaningful in semiconductor theory actually. You might
> be surprised, but the concept of a "hole" is just as valid for
> many concepts as an electron. The whole basis of semiconductors
> is actually the geometric combination of two types of silicon,
> those that have extra electrons and those that have extra
> holes.
>
> > correctly he surmised that in fact the current flowed backwards and
> > essentially the whole car was "live". I'm not buying it.
>
> Well, he's wrong of course.
>
> The car is "live" if you are stuck in the notion that
> to be more positive is to be more live. However, it is
> of course meaningless, either way of looking at the world
> works.
>
> His statement is misleading because it implies that
> the whole car is "live" and requires special attention
> to prevent giant sparks. I think he is confused beleiving
> that the chassis is positive but somehow lights and
> accessories are grounded negative. This would imply that
> the whole car was live and the possibility for shorts
> would be enormous.
>
> In reality, it's just the same thing backwards. No
> difference in relative "live" ness. On a normal car you
> have to be careful when working with wires that are
> positive since they can short. In your car, be careful
> with the negative wires.
>
> --
> Trevor Boicey
> Ottawa, Canada
> tboicey@brit.ca
> http://www.brit.ca/~tboicey/
--
Schuyler E. Grace
schuyler@bellsouth.net
schuyler.grace@atl.frb.org
http://members.tripod.com/~schuyler/
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