Help with TC - Updated

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

Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

Hi again - A few additions/more information about this coil.

Currently, I get about 1 or 2 foot sparks into the air, and only around a
foot to a grounded rod.  Without a grounded rod there are _many_ streamers
coming from the coil - not only the top wire bot the top few turns as well.
The capacitors for the MMC are from LLNL (Lawrence Livermore National
Laboratory) and are specifically for pulse applications.

Using the reactance method (calculating the impedance of the transformer and
finding the appropriate capacitance to match this impedance), I came up with
about 35 nF, how did you arrive at the 0.004 mfd? or is this millifarad
(10^-3), and I'm assuming you mean microfarad (10^-6)?  (more prefix
problems . . .)

I definitely want to get a toroid made, however I'm at school right now, in
Indiana, and live in California, so my TCs get out on hold for a majority of
the year, however, I am trying to start a TC club here at my school (1600
undergrad students, all engineering here . . .)

Also, anyone out there from the SFBA, who would want to try to pool
resources for a TC project?

-Sean Taylor



Original Question from me:
> In a message dated 1/11/02 1:18:18 PM Pacific Standard Time,
<mailto:tesla-at-pupman-dot-com>tesla-at-pupman-dot-com
> writes:
>
>
>
> Hi all,
> I have several TCs that I have been working on for quite a while, and
> it seems that I can never get arcs nearly as big as people have said
> on webpages, on the list, etc. for the same input power.
>
> Currently, I am running a coil with two 9k60 NSTs in parallel, a PE
> homemade cap of 35 nF, 3/8 copper tubing for the primary, and 22 AWG
> wire for the secondary on a 4" PVC form, about 28" tall.  The primary
> is an inverted cone, about 30 degrees, and has about 10 turns (should
> be more?). It seems like I can only get it to run somewhat well if the
> primary is tapped all the way in at around 2 to 2 1/2 turns, and wont
> run well anywhere else.  I don't have an output terminal, and I know
> this would lower the operating frequency, and then I would have to tap
> it out farther.  Also, do the wire lengths from the cap to the primary
> make a huge difference? They are 10AWG, but are about 3 feet long
> almost, as my cap is in 4" PVC, a rolled type, so the terminals are
> fairly far away. I just bought 12 0.05uF -at- 10KVDC caps for a MMC.
> Will this help a lot? I am using a RQSG, with 9 sections, and a fan to
> quench the spark.  What else could be improved, or what more
> information is needed?
>
> Thanks for any help anyone can provide.
>
> Sean Taylor