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Re: Toroids and noise. (fwd)
Subject: Re: Toroids and noise. (fwd)
Date: Sun, 4 May 1997 18:08:59 +0500
From: "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
On Fri, 2 May 1997 22:34:23 -0600 PWAC Inc.
<pwac-at-mail.flinet-dot-com> wrote;
> First, can I make a toroid (like a 3" outer ring diameter, with a total
> of 12" wide) by covering foam toroids they sell in craft store with
> aluminum foil? I can't see why not? I think it would he a real good one.
Yes, it won't be great on looks but it will work. You might want to
cut some rigid plastic sheet into a circle thais a SNUG fit inside
the toroid and glue it in place the cover it and the toroid with
aluminum foil (glued on) or aluminum tape. This way it will be easy
to punch a 1/4 inch hole in the middle of the disk to connect it to
the top of your coil.
> Anyone try Bronze or Silver (or whatever) plating these foam toroids,
> and some how connecting it to the top terminal of the secondary??
Yes, I have done this with toroids and even made large spheres for
Van De Graff generators. What you ha to do is go to a hobby store and
get styrofoam filler and paint or spray ot on the foam let it dry and
then sand it down to get a smoth non porous surface. Next go to an
Electronics supply house that supplies to the T.V. repair industry
and ask for Aquadag spray, it is a conductive spray that is used to
create ground plains inside T.V. and monitor cabinets. Spray the
Aquadag over the toroid and let it dry then connect a copper whire to
it and get you copper plating soloution (copper sulfate and get a
foam brush and connect a wire to the brush making sure the wire goes
deep into the foam from the handle end. connect the brush to the
negative terminal of a D.C. supply (0-12V at several amps) connect
the toroid to the positive terminal. Now dip the prush in the plating
soloution and act as if you were SLOWLY painting it onto the toroid.
You will see a gradual build up of copper on the toroids surface. Do
the entire toroids surface several times then disconnect it from the
power supply and wash it well then gently buff the surface with a
soft wool cloth to burnish the copper. If you wat it silver plated
then repeat the process using a silver plating soloution instead of
the copper sulfate. BE CAREFULL most silve plaiting soloutions
contain cyanide. DO NOT ALLOW ANY KIND OF ACID TO MIX WITH IT!
The reason for copper plaiting first is due to the fact that copper
makes a tighter bond to the Aquadag than any other metal, so this
procedure prevents future flaking of the plating.
Note: It's been a while and I may have the polarity wrong, so if it
dosen't start plating reverse the lead polarity.
> I have a sh_t load of Bronze plating stuff in my utility room, I'm sure
> I would first paint/coat the foam with something like polyeurythane (sp?)
> and make sure its REAL smooth, then coat it with the chemicals and metal
> powders, anyone tried/thought about this?
I remember reading in an old Popular Science (1940-1950) about using
paint containing metal powder to coat things like babys shoes,
leaves, ect. and then plating them, so it might work.
> Also, how loud are these spark gaps suppose to be!!
An unloaded spark gap can be VERY LOUD and VERY BRIGHT . When
connected in a Tesla coil the spark gap is quieter because more of
the energy is being used by the primary. Be carefull not to stare
into the gap though it is rich in short wave U.V. and it can BLIND
YOU. I like covering my gaps and I use a sheet of welders goggle
glass as a view port.
> I made a very small rolled cap out of 2 .74 mil white kitchen trash
> bags, sliced up and rolled to make a cap about 3" tall, and about
> 2" diameter (note: there was about 32 x.74 mils on every turn), can
> someone calculate this out for me? If you can calculate these, can
> you find out how many I would need to complete 0.0047 uf?
Your going your need atleast 20 layers of this stuff between the two
foil sheets to prevent breakdown at 12KV. Polyethylene may be rated
at 1200 volts per mill but thats for pure polyethylene. What you have
is far from pure it has additives to give it the white color and
additives to make it biodegradable. I would not suggest using it.
Much better to go to a building supply house and get a roll of clear
6 mill poluethylene it is almost pure and being thicker you will
need less layers, only 4 for 12KV rather than a next to impossible to
work with 20 layers.
> Also, does it mater if the material is biodegradable? Will it break down
> over time, or does it need sun light or bacteria for that?
It depends on how they make it biodegradable. Pure Polyethylene gets
brittle and breaks down to a powder upon exposure to short wave U.V.
If the manufacturer added substances to the polyehtylene to make it
break down in a land fill then it might slowly break down in your
capacitor, again it is much better to get polyethylene from a home
building center and not have to worry.
> I had this going with no oil, kind of like a test run, and it scared me
> it was so loud, I was jumping a 1/2" spark, it was so loud, If I left it
> on I could have gotten complaints from my neighbors, or maybe from the
> cops (If my bass wasn't enough for em :)
For the size transformer your using you would never use a 1/2 gap!
Even if there was a need to, you would use several smaller gaps in
series and the noise would be much quieter. You can enclose your gap
in a kind of muffler but make sure it has good air circulation to
maintain good quenching.
> It totally disintegrated the metal tacks in about 4 seconds. I am going
> to trash that cap, or I may take it apart and steal back my aluminum!
I remember in some of my early Tesla coil I used glass plate
capacitors that were hooked across the transformer and if something
jared a wire loose the cap would arc internaly. It would sound like
machine gun! After one of the glass capacitors exoloded, throwing
bits of glass all over the room, I swore off glass caps.
> Also, can someone tell me what U.S.P stands for? I purchased some
> mineral oil, and it is written on the container.
U.S.P. stands for United States Pharmaceutical, it is a designation
of purity. There is Reagent grade chemicals which are extreemly pure
and extreemly expensive. Then the is U.S.P. grade which are certified
not to have any impurities that would either interfear with the
chemicals medical use no be toxic to humans. Then there is Technical
grade chemicals which are not as pure as U.S.P. but adequite for most
manufacturing processes. Then there is commercial grade which is
anything but pure, I've seen this grade have everything from rocks to
hairs and bugs in it! This is typical of things like rock salt for
road use.
Sincerely
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Alfred A. Skrocki
alfred.skrocki-at-cybernetworking-dot-com
.ooo0 0ooo.
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