Re: Best, easy way to protect NST?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gregory Hunter" <ghunter31014-at-yahoo-dot-com> 

Hi there Jack,

First off, the NST protection circuit is optional.
Many coilers skip the filter and claim great results.
I prefer to use a filter--just in case.

Secondly, the little airwound chokes featuring a few
turns of wire wound on a small diameter form are of
questionable usefulness. The HF, VHF, and even UHF
products of the spark gap may blow right past them and
kill the NST with corona. Worse yet, a hi-Q choke can
"ring up" to high potential on its own, sort of like a
baby Tesla coil, possibly making things even harder on
the fragile NST secondary.

If you decide to use an NST filter, I suggest the
proven RC design. These feature caps in shunt with
each HV NST bushing, to short radio frequency products
to ground, and resistors in series to provide
isolation for the filter caps and to spoil the
filter's Q, making the thing nearly "ring proof".

Combined with a safety gap to remove high voltage
spikes, the RC filter has a proven track record for
defending NSTs from premature death. Here is a simple
diagram:

http://hot-streamer-dot-com/greg/filter.htm

The so-called "Terry Filter" is an improved version of
the RC filter. If you don't mind spending a little
more money and investing a little more time, it offers
superior NST protection compared to a plain-Jane RC
filter.

->Terry will add the links ;-) <-

http://hot-streamer-dot-com/TeslaCoils/Misc/NSTFilt.jpg

http://hot-streamer-dot-com/TeslaCoils/Misc/Filter.jpg

Cheers,

Greg

--- Tesla list <tesla-at-pupman-dot-com> wrote:

 > Original poster: "Jack Vandam"
 > <snotoir7674g-at-mindspring-dot-com>
 >
 > Around the web, I've noticed various coilers placing
 > small, rf chokes on the
 > output of their neon xformers.  Since I'm throwing
 > together a coil later
 > this week, I'm curious if there is any specific
 > formula for these chokes as
 > I'd like to add some protection to the NST I'll be
 > using.  Also, how
 > effective is the protection offered by these chokes?
 >
 > Thanks,
 > Jack
 >
 >
 >


=====
Gregory R. Hunter

http://hot-streamer-dot-com/greg

_