Dave copied us from a Mini site as follows:
"....When very early cars were built with negative earths (ie. the negative
terminal of the battery connected to the chassis) it was found to cause
excessive corrosion of the battery terminals compared to
positive earth cars. Positive earth cars also required 10% less voltage from
the ignition to produce the same spark. British car manufacturers changed to
the then superior positive earths but European and American manufacturers
retained negative earths....."
I may be doing dishonor to the institution that granted my MS in Physics, but
I don't yet understand how this can be. I know how a battery generates a
potential difference between its terminals via a chemical reaction, and
understand in terms of atomic charges, electrons, and "holes", why current
flows via a conductor from an area of higher potential to lower electrical
potential. I don't understand how the terminology we use ('+' and '-') can
generate a hotter spark in a transformer coil depending on which one we
define as "ground".
"Won't somebody help that poor man?"
Lannis
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