Re: spark gap spacing

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

Original poster: "BunnyKiller by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bigfoo39-at-telocity-dot-com>

Tesla list wrote:

> Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<scepp-at-mts-dot-net>
>
> Hello Again,
>
> I Have another question,
>
> Does anyone have more exact information to setup the gap distances on a 12Kv
> at 60mA neon sign powered tesla coil, I've seen the SGapVolt.jpg file on
> Terry's web page under misc and its kinda rough, but interesting.  Anyway,
> I'm looking for the safty gap distances to ground, and the main spark gap
> distance for a 2 gap (I hope 2 is enough) spark gap using 3/8 inch tungsten,
> flat surface, oh and the safty gaps are ~3/8 inch brass balls.
>
> I know I've seen the equation for  Kv/cm spark jump somewhere, but it
> doesn't include electrode shape, and I figure that there is lots of people
> out there using very similar hardware so I'm hoping I don't have to do it
> trail and error.  :-)
>
> BTW.  I was thinging of using Drill bits to gap my spark gaps,  does this
> work well??
>
> Thanx,   Shaun Epp

Hi Shaun....

setting spark gap distances vary from coil to coil ...
but if you are looking for a general rule of thumb type of setting....
12KV = 1/4" - 1/2"
(max) for single gap ( 2 electrodes)...

to fine tune your gaps you need to run the coil and LISTEN to the coil it
should have a
clean 60Hz buzz when running ... if it has a crackling sound, the gaps are
a bit on the
wide side...

as far as safety gaps go, preset the normal gaps to 3/8" ( use drill bit)
and set the
safetys to 3/16" on each side of the center ball, run coil and see which
gaps fire more
often. If the safetys fire more, open the safetys about 1/16" each. rerun....

the open air equation used pin points for the standard...  spherical
electrodes have a
higher hold off value than pin points...


Scot D