les wrote:
Joe...
Interesting possibilities to ponder.........
How does aluminum account for overvoltage? If it has an inherent
higher resistance,

The power to your home is supplied at 240V. It is split 120V on either
side of the neutral. The neutral is connected to the ground, but it is not
a ground. Each 120V circuit is one one or the other side of the neutral.
If you had two 120V circuits with exactly the same load (say 5 100W lamps)
then the they would be balanced and current would flow only on the two hot
wires and nothing on the neutral leaving your home (you have three wires and
maybe a ground coming into your home.) however if one of the lamps went out,
you would have about one amp more going through one side than the other so
the difference would flow through the neutral OK I am getting to your
question. With aluminum wire, connections tend to get flaky so it is
possible that the neutral may not make good connection so the set of 5 good
lamps would get less current and be a little dimmer and the side with 4 good
lamps would be brighter.

If you have aluminum wire coming into your home from the street, that's
OK they use special designed fittings to eliminate the problem, but if you
have it inside your walls running to outlets, it can be a hazard because of
the bad connections.


I would expect the opposite.
What about a floating ground? It would have a lower differential to
the mains.
Please qualify how this would work.
Thanks


Les KA9GLW
I agree with the overvoltage as a consideration, but I can't see how
this could
happen in practice.
My other thought is that these bulbs are not the tungsten variety,
but the halogen
type. It's known that the ion exchange between the halogen envelope,
the gases and
the filament are tuned to work at specific temperatures. If you try
to alter the optimum
operating temperature, they fail much quicker. So, don't dim halogen
bulbs. It doesn't
extend their life, but shortens it. A soft start would be an
exception, I'm sure.

--
Joseph Meehan

Dia duit