Re: SMALL SPARKS: PLENTY OF POWER- NO TIME

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Jeremiah,

You mention that you have no room for a flat spiral primary but that 
would seem to me where
the problem possibly lies. A helical primary makes
it difficult to obtain tight enough coupling without
getting those annoying (and destructive) racing sparks up and down 
the secondary coil when in
operation. 3.5 ft. isn't specatacular performance
for 120 volts at 20 amps but "I" wouldn't consider
it necessarily "dismal" either. I'm sure that you're probably hoping 
for 5 to 6 footers with your power
consumption, though. If you are not able to change
your primary coil to a flat spiral, then I would sug-
gest removing most of the upper unused portion of the primary that 
you have and raising the rest of the
used part of the primary coil higher relative to the secondary until 
racing sparks just start to form and then
lower the primary back again to just below where
the racing sparks stop. This should give you near optimum coupling.

Aso, your secondary coil is a little on the "skinny
side" of  the optimal height/diameter "aspect ratio"
of the 4:1 to the 5:1 range. It's still reasonably "close enough" 
though but would also aggrevate the too loose coupling issue.

Also, are you utilizng any PFC caps with the input
to your NSTs? Proper power factor correction may
help reduce the current draw and get your coil to ope-
rating more efficiently where the wattage consumption
is closer to the actual volt/amps being drawn.

David Rieben

----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, October 24, 2005 11:37 AM
Subject: SMALL SPARKS: PLENTY OF POWER- NO TIME


> Original poster: tesla popp <teslas_lab@xxxxxxxxx>
> I would usually troubly shoot this sort of problem
> myself, but I am almost OUT OF TIME!  I have a show to
> do in 5 days!
> One of my coils has a BIG problem, It's drawing
> 20amps, and making 3.5 foot sparks.  This is VERY BAD.
>  I have no idea why it is acting up, but I belive it
> might be due to bad coupeling?!  {note: the winding
> starts 1" above the bottom winding of the HELICAL
> primary}
> Operation of the coil is VERY STEADY, and is NOT
> erratic at all.  I am pretty shure I have my SRSG set
> where it should be.
> [Note: please trust the specs I am providing]
> -The tranny is a 15/120NST "Draws more with my L.T.R.
> MMC"
> -A 120BPS sallent pole syncronious rotery gap
> -Secondary coil 6.25" x 40" 20awg, 1250 turns
> -helical primary 12.5" wide, tapped at 6 turns "no
> room for a flat spiral primary."
> -MMC is .05uF
> note- USE THE PICTURE LINK I HAVE PROVIDED TO SEE WHAT
> I AM WORKING WITH.  Any ideas will greatly help!
> http://www.amasingscience.com/teslacoils/images/TWIN_FULL.jpg
> http://www.amasingscience.com/teslacoils/images/TWINBIG_PRI.jpg
> http://www.amasingscience.com/teslacoils/images/TWIN_MMC.jpg
>
> Thanks,
> Coiler Forever: Jeremiah Popp