Re: Ink-core TC - Is it possible?

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

Original poster: "Mark Fergerson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mfergerson1-at-cox-dot-net>

Tesla list wrote:
> 
> Original poster: "Chris Roberts by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <quezacotl_14000000000000-at-yahoo-dot-com>
> 
> Hi everyone,
> 
>         I've always seen people building so called "mini" coils but have
> never seen one quite as small as I've thought you could go. So I got around
> to thinking about making a truly mini coil. By mini I mean wrapping the
> secondary around part of a Bic pen (about 5/16"). I then went totally nuts
> and thought about putting the entire coil (gap, cap, etc.) on the pen. I
> then would be able to put the whole thing into a larger pen case, and have
> one awesome writing tool! However, I am an extreme novice when it comes to
> tesla coils (I've built one standard coil before, and it still dosen't work
> as well as it should) and I dont know whether or not this could work. I
> know that I wouldn't be able to fit a 15/60 NST on a pen, so this would
> probably have to be OLTC style. Could the capacitors and IGBT's be small
> enough to do this? I first want to know if this is possible enough to
> actually try before I start thinking about details. Hope I'! m not being
> too vague (please don't hurt me if it is O mighty telsa list members ;-) ).
> Thanks.

  AFAIK a TC can be built as small as
you like as long as lumped-constant
assumptions apply so you can take
advantage of the work already done in
the modeling department by those more
able than I (see the pupman site for
links).

  But for a very small coil, first
consider the teeny-weeny inductance of
the secondary and the largest
capacitance load you can use. That sets
the frequency of the primary tank you'll
have to build, which will be rather high
WRT a "standard" coil, and it'll likely
mean a fairly small primary capacitance,
which means not much in the way of
energy to transfer to the secondary,
which means teeny-weeny streamers (if
any).

  I've been through this, and am looking
at all sorts of exotic solutions to pump
things up for my micro-magnifier, like
pancake coils for the pri/sec tanks and
a pressurized-gas-filled container for
the tertiary, with part of the
capacitance accounted for by the
coil/container spacing.

  I think I'm getting rather close to
the lumped-constant limits I mentioned,
and my math isn't up to the task of
figuring out where to start modeling it,
so I'm blowing things up with some
regularity even though I'm running less
than 100W. But it's lots of fun anyway.

  Mark L. Fergerson