Re: Tesla Coil Theory into Practice Problem (Beginner)

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

Original poster: "Terry Blake by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tb3-at-att-dot-net>

Hi Craig,

It sounds like the caps are blown.  For a quicky test, I'd suggest putting
together some beer-bottle caps.  You know, bottles, a tank, some wire, and
saltwater.  They are real easy to get together and plug into your system.

Initially, you could try just 1 bottle cap.  It could be a BIG bottle.  Fill
the bottle with salt water, drop in a wire for contact to that plate, wrap
the outside with alluminum foil, and wind a bit of wire around the foil to
make contact to that plate.  If the sparks start to fly, add more bottles
for more capacitance.  No sparks would tend to say that the transformer
cannot drive much current.


Best of luck.

Terry Blake


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, July 31, 2002 9:19 AM
Subject: Tesla Coil Theory into Practice Problem (Beginner)


> Original poster: "Craig Shaffer by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <bshaffer-at-coe.neu.edu>
>
>
> Hi,
>         Im Craig Shaffer I have been building a Tesla Coil for some time.
I
> currently cannot get my coil to work at all.  I have thought over time
that I
> had problems with my spark gap and the fact that I was feeding the Tesla
Coil
> DC (more on that later) but I have switched over to an AC input and a
rotary
> spark gap.  My problem is that my coil hooked up as show in most circuit
> diagrams simply doesn't operate.  I have the Cap in series with the
Primary and
> that in Parallel with the transformer and the capacitors.  What happens is
that
> my capacitors appear to be a dead short and all power is drained through
the
> primary and I don't get even the smallest spark at the rotary gap (even
with
> the motor off and the electoded inbetween the posts).
>
> My specs
> - Two X-ray transformers (currently using one)  I took out the DC bridge
> because no one seems to use DC for their       tesla coils.  The one
> transformer is hooked to an Auto-Transformer which allows me to select any
> voltage from 0-        60KV.  I don't know the output amperage and have no
way
> of measuring it but it's probably pretty high I given the
requirments of
> medical x-rays.  If you have any suggestions as to how get an idea of how
high
> it is let me know.  I     know when the transformers are running at 40kv
the
> jacobs ladder produces a hot arc about 3 inches long.  Perhaps this really
> falls off when the voltage gets under 15kv???  Can anyone give me a
comparative
> experiment if they think this might be the problem.
>
>
> -3 rolled plate caps similar to specs found on the net& Assumed to be
about .01
> mfd at 30,000dc or 15,000ac.
>
> -Rotary gap driven by grinder 8 electodes 2100 rpm or so. (Will get a
variac on
> it but need to get the rest working first)
>
> -8"X31" Primary #26 wire approx 1350 turns
>
> -Flat pankake type primary 18 turns 9" inner diamiter spaced every 1/2"
3/8
> copper tubing
>
> I've been working on this thing for some time and im really pretty
> frusturated.  I was trying to get into D.C input because no one had done
that
> before.  I was able about a year ago to get 8" streamers when the system
was
> driven by D.C but the cap's were in parallel with the transformer and I
was
> using D.C   I thought the fact that I was using D.C was the problem so I
tried
> to just get it to work by switching to A.C and still I have nothing.
>
> The real question is why does the capaciator bank appear to act as a short
> circuit dawingl the energy away from the transformer making the sparkgap
> inneffective.  I left the transformer on for quite a while thinking it
might
> just take time for the caps to charge but this didn't happen.  I have
tested
> the caps all one at a time and them seem to work (they hold/store a pretty
nice
> charge a spark when you charge them remove the transformer and short them
out)
>
> Thanks for all your help
> Craig
>
>
>
>
>
>