RE: toroid for my coil.

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

Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com> 

Choosing the optimal top load size is unfortunately one of the remaining
frontiers in our art.  There is no formula, or even an agreed-upon rule
of thumb.  I based my advice on the fact that I had used a 7x30 toroid
on my 15/60 powered coil.

There are no doubt many things that factor into this.  I don't believe
in advice basing top load size on X times the secondary height or
diameter, or anything else so simple.  Clearly, not everyone who builds
a 15/60 powered coil achieves the same results.  If there is something
else in your design that might reduce the performance - coupling, bang
size, etc, then even a 4x30 toroid might be too big.  All one can do is
build it, see if it looks like it needs a bigger or smaller one, and try
again.  No one ever gets everything perfect the first time, if ever!

Regards, Gary Lau
MA, USA


Original poster: "Luke" <Bluu-at-cox-dot-net>

Wait!
I was under the impression this size toroid might be too big and I may
not have break out.  If you are telling me I might have multiple
streamers rather than a single long one that means it could be bigger
right?
What would be in your opinion the largest size I should put on this
system?

Luke Galyan
Bluu-at-cox-dot-net

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, January 23, 2004 7:10 PM
To: tesla-at-pupman-dot-com
Subject: RE: toroid for my coil.

Original poster: "Lau, Gary" <gary.lau-at-hp-dot-com>

The 4x30 toroid will definitely work; you may just get multiple shorted
streamers rather than the longest possible single streamer.  Mostly a
personal preference thing.

Gary Lau
MA, USA


Original poster: "Luke" <Bluu-at-cox-dot-net>

I will be using a 15/60 NST a cap size of about .016 mfd and I have
finally
decided to go the static spark gap route for this coil and attack the
SRSG
later if I get the bug. (thanx everyone for the info there may be a
round 2)

I was going to use a toroid of 4" minor dia and about 18" major dai.
I happened to buy some flexible duct from McMaster carr and it is 4 1/8"

dia but the smallest I can roll this stuff is like a 30" outer dia.
would
this be out of the question for my toroid size?  I would still be at eh
4"
minor dia so the voltage breakout would be the same (I think)  but I am
a
bit confused as to how to figure out if there will be enough joules
produced to use a toroid of this size.  Seems there is no exact way of
figuring this out as a definite.  So thought I would ask the experienced

ones what they thought.

I like this ducting and really want to use it.  But if there is no way
it
will work with this coil ill have to figure something else out.

Luke Galyan
Bluu-at-cox-dot-net