[Prev][Next][Index][Thread]

Re: Tesla Secondary Dilemma



Hi Russel,

> Original Poster: "Russell Milliken" <bigruss-at-orcon.co.nz>
>
> I think my TC secondary has too many turns on it. I made the secondary
out of a
> 26" long, 5.5" (outer diameter) PVC. The winding is 22" long. Trouble is the
> magnet wire I had was 0.16mm diameter, which translates to 50-60 turns
per cm,
> or 125-150 turns per inch. Thus there are around 3000 turns of wire on the
> secondary. I gather this may be too many turns. Can this secondary be saved
> !!!!
> As you can imagine I'd rather not wind another, and this one is so pretty.
> Any suggestions anyone?

I agree with Terry's posting on this. You used basically 34 awg magnet
wire. There
is something else you could do (although you may not want to).

If you double up 60mA xfmrs for 120mA, you could use a 20nF cap size to
close in on
resonant charging. This will decrease primary turns some. Now here's the
"may not
want to" idea. You could "cut" down the secondary to a 3:1 h/d ratio which
would
then be 17" height (~2k turns). By doing this and using a top load of 24pF
(4" x
23"), your primary could then get down to 20 turns using a 9" inner diameter (I
would use a 9" I.D. allowing ~1.75" between secondary and primary windings).

Just an option and probably the last. Usually, it's the cap size that is the
problem. Here is one of those situations where the MMC cap bank could come in
handy. But, if I was in your situation and wanted to put this coil to use,
I would
probably try other things first, like Terry's idea of just using a coil of
wire to
get to the inductance required (keeping the wires separated for voltage
standoff).
I also wonder if dual-stacked primary's might be another alternative to get
to the
needed inductance? (imagine two 15 turn primarys series connected). Might
even keep
overall cosmetics nice.

Bart