Re: primary voltage again

At 01:01 PM 2/16/96 +0700, you wrote:

>I have been wondering for a long time about the input voltage on a tesla coil
>side of tesla coil secondary side of power xfmr). I have heard several times
>power is the determining factor in spark length. If this is so, will you get
>the same
>results with the following?
>5kv-at-2a, 10kv-at-1a, 20kv-at-.5a, 50kv-at-.2a, and 100kv-at-.1a.
>Why does not anyone use 5kv or 50kv? What is the highest voltage anyone
>has pushed to and what were the results? I asked before and only heard from
>teslakd-at-primenet-dot-com (Thomas Kelley). his work was with 85kv-at-?ma, he
>said the results were about the same as a normal tesla coil, but with more
>electrostactic properties (not sure what that means).
>But he was using 22 .01uf caps in series. What if he had used the same value
>cap and primary turns that you would have with a standard coil setup (for
>a given xfmr power and coil frequency)?? I would like some real life feedback
>this with detailed explainations from everyone that has the time.
>                                      Kevin M. Conkey

Again, a few comments...

Say you have a .1 uf cap and charge it to 5Kv. It will hold just so many
electrons at this voltage, lets say 20 gazillion electrons...

Then charge it to 10Kv. It will now hold twice (I beleve, I'd have to check
the books) the number of electrons as when it was charged to 5KV. You now
have twice the electrons at twice the voltage, this is four time the power !

Repeat the excercise, ad nausium...

The key is matching your primary voltage to the Cap.

The only real problem is that as votages get higher, it gets harder to
prevent flashover on the primary, and you need to increase spaceing and/or
insulate the turns - which is fine for really large systems, but would be
more difficult for a smaller coil setup

Higher voltage caps are harder to find, and seem to be more expensive, and
from my (limited) experience,
it's simpler to work with lower primary voltages. Less insulation problems,
corona leakage, flashover, and parts are easyer to find.

Richard Quick's coil on his video is running about 20Kv or so, and works
fine. (to put it mildly)

My last coil ran great on 5Kv, I just had to pay a lot of attention to the
gaps - at 5Kv you need lots of really small gaps. I was blessed with an old
industrial radio-frequency heater, which had the 2KVA 5Kv transformer and a
nice set of gaps. I just had to rewind the primary and secondary, and
instant 2 foot sparks !

I guess what I'm trying to say, is that almost anything can be made to make
nice sparks, using what you might have on hand, but EVERYTHING interacts in
designing a system, which drives most beginning coilers slowly nuts...

I design any given coil by looking at what equipment I have (or plan to
get), and then designing the rest of the system to match. Richard Quick's
rules of thumb work very well for designing a system.

There is no such thing as an 'optimium' system, there are too many good
ideas and ways of fudging things to increase performance.

Please feel free to punch large gapeing holes in the whole cloth of my logic !

Daryl (climbing down ,exhausted, from his soapbox)