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Old 03-22-10, 01:35 PM   #20
Xringer
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At the lower voltage ranges (that you might need in a house), DC voltage needs
a Large amount of current..

So, if you have a few thousand feet of wire, it has to be Monster cable..
Otherwise, it will have significant resistance..

Notice that voltage isn't a factor in this formula, P=R x I squared..
In other words, if you have some Resistance, the Power loss will go up with the square of the current..

That's why we no longer use any long low voltage DC lines..

When I was a young man working in Boston, one of the old Phone co. buildings had 110VDC outlets in the offices.
Once in a while, someone would plug in an AC device and watch it smoke..
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