Square Wire, COAX & Ground,frozen
To: mail11:;-at-cimcad.enet.dec-dot-com (-at-teslatech)
Subject: Square Wire, COAX & Ground,frozen
From: I am the NRA <pierson-at-cimcad.enet.dec-dot-com>
Date: Tue, 21 Mar 95 18:56:32 EST
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The litz wire discussion got me to speculating...
There IS such a thing as sqaure section wire. Really. Its used in places where
ultra high packing density is more imprtant than cost, in motors and
transformers. Dunno how available it is, but its real. Especially big gain in
single layer coils (tesla secondaries...).
Consider that resistance is 1/A
For round wire A=pi*r**2
For Square: A=(2r)**2 (putting the dimesions in the same form...)
So the ration is 3.14/4, or 4/3 in conductivity, roughly, improvement.
Now that assumes conduction thru the whole wire, which the LF of the tesla coil
won't, so Assume its all on the surface:
Circumefrence of circle: Pi*D
"cirumference of square: 4*D.
hmmmmm. either way, there is a 30% drop in resistance for the same length of
wire or coil..
Hard to get, likely costly.
Might Corona more.
Some transformers are "foil wound", that is, flat sheets of foil, rather
than wire. Can't see how to do a secondary that way, but a primary,
like the pancake or spider coils???
used coax, cheap shows up at ham flea markets, rangeof sizes. Smart
hams DON'T use it because the MF/VHF performance is dicey, as the
dielectric gets phunny with age... Perfomance t coild freqs ahould be
ok, i think...
Its a finicky thing, perhaps, but if the shield of the coax is grounded,
suitable safety gaps, to save puncturing the insulation if things get
out of control migth be useful. The coas itself is easily replaced,
but "collateral damage" could be avoided.
Frozen Grounds (now that things are thawing....)
How deep things freeze depends on where one is. Around here a wise
person puts their water pipes 6 feet down. I have seen them freeze &
burst at 5 feet.
Freeze some electrodes in an icecube and check the conductivity.
(semi serious suggestion...) At DC, 60 Hz and operating freq.
With multipoint grounds its not hard to measure from one to the
next, with a little planning. Again at DC, 60 Hz and operating freq.
The measured results will be worth more than all my ramblings...