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RE: Where to look?
Original poster: "Vanderputten, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <gvp-at-pvaintl-dot-com>
Jim
No real experience with running that close, so my advice is to be taken with
a grain of salt.
You should read some of the many threads here on CAP voltage Vs tank
voltage. Due to the behavior of the tank circuit, actual voltages peak way
above the plate voltage of the NST. Hence, the safety gap(s) to protect the
tranny and the CAP. Most of the experts here recommend that to protect a
cap, the cap voltage size should be 2 to 3 times the plate (NST) voltage.
You also have the additional problem that most caps are rated and tested for
peaks in DC, not AC whose peaks further stresses the caps. Caps are
expensive. I have a 3x2 MMC of six 10kv DC/.10mf pulse caps (from EBAY)
giving me 30kv DC/.0066mf cap. About a $50 investment. At 12 kv it is fine,
but 15 kv is not advised. I have built many coils in my life, and have blown
lots of NSTs and caps. Since following the consensus of advice in these
threads on the subject of protection I have not lost a cap, tranny, or fried
any domestic electronics.(Yet).
And, I like your kit and your capo; you seem to have plenty of room/
capacitance to take on more current; and with more primary windings it
should fly.
Gary
-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, March 22, 2002 9:59 AM
To: tesla-at-pupman-dot-com
Subject: RE: Where to look?
Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<jim-at-jlproduction-dot-com>
You wrote:
"Your cap's 15 KV is too low to take on a 12kv."
Are you sure about that??? It is rated in AC and I have heard coilers
using this same cap to run twin 15/60's!!
Just wondering
Jim
-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, March 21, 2002 8:22 PM
To: tesla-at-pupman-dot-com
Subject: RE: Where to look?
Original poster: "Vanderputten, Gary by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <gvp-at-pvaintl-dot-com>
Jim
I recently built a very similar coil - based all measurements on that
spread
sheet everyone uses, I mean exactly and the coil responded as predicted.
MY secondary 3 1/2 " by 900 turns of 22.
You have more cap than I -15kv/ .01 Vs 30kv/.0066
My primary has 16 turns, yours about 12.
My tranny is a 12/30 or 12/60, hence the larger Kv on the cap
Sam RQ gap - 8 gap pipe with fan
Torroid - 6" copper float
I have a 'Fritz/Lau" LCR protection circuit for the tranny and my
apartment,
but this shouldn't affect performance.
Tuning - I use the entire primary and most of the gap (adjusting the
latter
just changes the streamer in length Vs form)
My coil runs cool and noisy with about 15" arcs to a good rf ground at
70vac
on the variac- easy to get more once I leave the building.
I think that you can goose yours up two ways -
Try a 9/60 tranny - very significant change when I went from 12/30 to
12/60.
Your cap's 15 KV is too low to take on a 12kv.
Increase the primary turns
Good luck.
Gary
Original poster: "Gregory Hunter by way of Terry Fritz
<twftesla-at-qwest-dot-net>"
<ghunter31014-at-yahoo-dot-com>
Spark Gap! If you only improve one thing, improve
that.
My $.02 worth,
Greg
http://hot-streamer-dot-com/greg
--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <jim-at-jlproduction-dot-com>
>
> Hi all,
> As I prepare to have at my coil this weekend I was
> wondering where I
> should focus my attention as to better
> spark length?
> I realize this is the 10,000 dollar question and
> also that experiment is
> king, but any hints are more than
> welcome.
> To give a pretty good idea of how I did on round one
> I have used Paint
> Shop Pro to enhance the contrast on
> one of the better pics I took. This modified pic can
> be seen here...
> http://www.jlproduction-dot-com/sparkmod1.jpg
>
> Or the whole site can be seen here...
> http://www.jlproduction-dot-com/Tesla.html
>
>
> The toroid is 14 inch diameter to give you a scale
> to work with.
>
> Thanks in advance for any and all ideas,
> Jim
>