RE: Static Spark Gap question

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

Original poster: "WIZZARD ." <pbobyk-at-hotmail-dot-com> 


GARY

I have been led to believe that overstressing a component beyond what has 
been designed to do is just asking for trouble. ( I know an NST was not 
made for a Tesla coil ) I guess I'm being too cautious? I have not actually 
tried this on my system because of the high cost of replacing my transformers.

I stand corrected on the gap issue too.
What seems logical doesn't always make it true :-)
Web of a million lies.... I hate to be contributer to that.

Thank You for the corrections.

I would like to understand why. If you have the time.

Wizzard
Dwight, Ontario
Canada

>It is commonly assumed that a multi-segment N-segment gap of X inches per 
>segment will have the same breakdown voltage as a single (N*X) inch gap.
>This is not at all true.  The only way to determine the proper number of 
>gaps in a multi-gap is to do so experimentally.
>
>What's wrong with applying 140V to an NST through a Variac?
>
>Gary Lau
>MA, USA
>
>
>
>Original poster: "WIZZARD ." <pbobyk-at-hotmail-dot-com>
>
>Apply the 15KV accross a safety gap and adjust it so it "just" stops arcing.
>Remove power, then measure the opening of the safety gap.
>Divide this number by the number of gaps between your pipes.
>Pipes should be installed as parallel to each other as possible. Each gap
>doesn't have to be perfectly spaced unless you really like that appearance.
>
>More pipes means less space in between each pipe.
>Small gap spaces get clogged and/or shorted by surface irregularities on
>the pipe usually in a short period of operation time. Overall coil
>performance suffers. ( Fine sandpaper time )
>
>My NST 15KV/120mA NST powered coil uses a RQ gap with 10, 3/4" Cu Pipes
>about 4.5" long.
>A good circulation of air through the gaps is needed for this power level.
>
>Tips to avoid dissapointment :-)
>         1) Don't make the main gap larger than the safety gap.
>         2) Don't use a mains resonant capacitor.
>         3) Don't apply 140 VAC to NST through a variac.
>         4) Use a Terry Filter!
>
>Members correct me if I'm wrong.
>
>
>
>
>
>
>
>
>
>
>
>
> >Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>
> >
> >Hi All,
> >
> >I'm building a 15kv 120ma coil system and want to start with a
> >multi-segmented spark gap.  I know that Dr R doesn't like total spark gaps
> >in excess of 240 mils but I do plan on setting my safety gap appropriately
> >and leaving it alone.  I'm planning on a 16 pipe string with each copper
> >pipe being 3 inch long by 0.625 diameter.  Three gap spacing arrangements
> >are being considered that will allow me to vary the total gap in 5 mil
> >increments.  This will be done by having the center gaps be of smaller
> >spacing than what the string is based on.  The smaller gaps will be
> >shorted out (as necessary) in various combinations to get the 5 mil
> >increment.  The following shows the smaller gaps in the center of the
> >string based on 20, 25, and 30 mil spacings:
> >
> >a. 20 mil spacing   .... 20 10 15 20 ....            maximum total gap 285
> >mils
> >b. 25 mil spacing   .... 25 10 15 20 25 ....       maximum total gap 345 
> mils
> >c. 30 mil spacing   .... 30 15 20 25 30 ....       maximum total gap 420 
> mils
> >
> >Questions:
> >
> >1. For this power level, what is the current thinking on maximum number of
> >segments?
> >
> >2. Is there a rule of thumb on the maximum gap between any two segments?
> >
> >3. What is the "expected" optimum total gap required for this power source
> >and how much would this need to be increased for my 5000 foot elevation?
> >
> >Answers to these question will help me identify a design center and choose
> >an appropriate spacing range.
> >
> >Many thanks for any help,
> >
> >Gerry R
> >Ft Collins, CO
> >