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Re: tesla coil



Original poster: "Joshua Lovato by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jlovato-at-newmexico-dot-com>

Transformer voltage: Some where between 9-10kv. The transformer was given to
me by a friend of mine at the local radio station and has no name plate or
any type of label on it :-(.

Transformer current: 20-30mA, is there a way for me to measure the current
of the transformer? possibly by setting a meter to read current and
connecting it across the transformer before plugging it in?

Primary coil inner diameter: 5 inches

Primary coil turns: 3 made of 12 AGW wire.

Primary coil distance between turns: .25 inches

Primary cap size : 12nF

type of spark gap: Multi point spark gap made with 8 1/2" copper tubes
bolted to the inside of a 3 inch PVC pipe

Secondary coil diameter: 1.75 inches

Secondary coil turns: 680

Secondary coil length: 8 inches

Height of first turn of secondary coil above primary coil: 1/4" from the
bottom of the primary (im using a Helical primary). I found that if i lowerd
the secondary coil further into the primary the output increased dramaticaly
( from 1 inch sparks to 3 inches).

Terminal diameter (side to side): You guys are going to laugh but I am using
a 1.5 inch Styrofoam ball wrapped with aluminum foil.
Height of terminal (center) above primary coil: 10.75"

I will be posting some pictures of the coil on my website as soon as I get
it updated :-)

Thanks for the help,
Josh


----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, January 01, 2001 10:40 PM
Subject: Re: tesla coil


> Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
>
> Hi Josh,
>
> A common problem with first coils :-)  Don't worry, we'll figure it out.
>
> I think you meant a 5 inch center primary taped at 3 turns and a 1.75 inch
dia.
> secondary with 680 turns of wire.
>
> The cap size for a 9/30 is 8.842uF resonant at 200 BPS and the LTR (static
gap)
> size is 12nF.  So you should be fine using a 12nF cap.  If your NST is
only
> 20mA instead of 30mA that may be a bit of a problem but I think something
else
> is wrong.  Info on this is in the tables at:
>
> http://hot-streamer-dot-com/TeslaCoils/Misc/NSTStudy/NSTStudy.htm
>
> My first guess would be that the primary and secondary are not tuned to
the
> same frequencies.  I don't have enough information to calculate the
frequencies
> here but If you let me know I can run the numbers.  I need to know the
missing
> info below:
>
> Transformer voltage: 9kV
> Transformer current: 30mA
>
> Primary coil inner diameter: 5 inches
> Primary coil turns: 3
> Primary coil distance between turns: ??
>
> Primary cap size : 12nF
>
> type of spark gap: ??
>
> Secondary coil diameter: 1.75 inches
> Secondary coil turns: 680
> Secondary coil length: ??
> Height of first turn of secondary coil above primary coil: ??
>
> Terminal diameter (side to side): ??
> Width of donut section if it is a toroid: ??
> Height of terminal (center) above primary coil: ??
>
> I think that is everything :-)  With this data I can pretty much figure
> everything out.  A 9kV/30mA NST should do about 25 inch arcs if everything
is
> just right, so something must be wrong.
>
> Cheers,
>
>         Terry
>
>
> At 09:05 PM 1/1/2001 -0700, you wrote:
> >
> > Hi I am new to tesla coils. I recently built a TC with a 1.75 diameter,
680
> > turn primary and a 5 inch helical sec taped at 3 turns. Im using a
9-10kv
> > 20-30?ma NST and a home rolled .012uf poly cap in mineral oil.  I was
able to
> > get 3 inch arcs out of the secondary. what would you sugest that I do to
> > increase arc legnth? could the problome be my cap? (the equations and
tesla
> > softwair originaly called for .0079uf caps but the capacity on my cap
went up
> > to .012uf after I put it in a PVC pipe and filled it with oil)
> >
> > thanks,
> > Josh
>
>
>
>
>