Subject: Re: NST for tesla coil question
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NNTP-Posting-Date: Sat, 11 Jan 2003 20:16:50 EST
Date: Sat, 11 Jan 2003 20:21:53 -0500
Lightning and thunder is what we want as the end result anyway, isnt it? :-P
True, Mylar is a good insulator, but its dissipation factor is terrible at
such high frequencies like a Tesla coil. Dissipation factor is how much heat
a dielectric produces when in use. This value increases as the frequency of
the application goes up. For my secondary winding, the resonant frequency
was calculated to be about 1.3 MHz, which an extremely high frequency for
any dielectric to work at. LDPE has a much lower dissipation factor, and is
used more frequently to make Tesla caps. For my cap I plan on building an
MMC out of Philips KP/MMKP 376's. Oh.. For you coilers out there, my
secondary coil is is 6.25" long and about 1" in diameter, with about 790
windings. I know, it's tiny! I am going to make a small tabletop coil with
it. Do you think that I might be overpowering this tiny coil with a NST?
What else could I run it off of? Flyback? Thanks for helping!!
"Sir Charles W. Shults III" wrote in message
> You will find that when building Tesla coils and other high voltage
> equipment, you are better off using 5,000 to 7,500 neon transformers.
> voltages make it difficult to produce good capacitors, because insulators
> down so easily at these voltages. A lower voltage transformer makes it a
> matter to make custom capacitors that will not break down or be as
> I learned this trying to apply 15 kilovolt transformers to Tesla coils in
> past. The losses are unacceptable.
> Mylar plastic sheeting and heavy duty aluminum foil are excellent
> for making your capacitors, as Mylar has an insulation breakdown voltage
> difficult to surpass. A 250 micron thick sheet has a typical breakdown
> of 27.5 kilovolts.
> Also keep one other thing in mind- DC and AC breakdown voltages can
> substantially, due to many reasons. In a Tesla coil, the voltages are not
> sinusoidal, so an AC voltage reading will not take peak voltages into
> You must calculate 3 to 4 times the thickness you would expect for an
> DC voltage to get the proper breakdown resistance.
> Otherwise, the peak voltages will puncture the Mylar and you will get
> lightning and thunder.
> Chip Shults
> My robotics, space and CGI web page - http://home.cfl.rr.com/aichip