Re: First Light but I have a Problem

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Emmett,

Make the toroid bottom "even" with the top winding of the secondary. Your 
problem should go away. Once verified, you can begin moving the toroid up a 
couple inches at a time. I suspect you'll end up about 2 or 3 inches above 
the secondary at most, but maybe not even that.

Here's why: the toroid is "wide" and the 4" minor diameter is small 
resulting in a weak shielding affect. A smaller outer diameter toroid will 
help here (I would go with 16 inch). The fact that your breaking out 
indicates the toroid isn't too big as far as it's capacitance is concerned. 
When the toroid "sheilds", it's capacitive loading changes the secondary 
distribution of current. The result is less voltage stress at the top of 
the coil and no premature breakout at the top winding.

Take care,
Bart


Tesla list wrote:

>Original poster: "EMMETT SECREST" <secrest2032-at-msn-dot-com>
>I lowered the Toroid an inch but it did not help the arcing at the top of 
>the secondary. The Toroid is now 5" above the top winding of the 4.5" dia. 
>secondary.  My Toroid is 23" major dia. and is made from 4" dryer duct. I 
>have a 12/60 NST powering my TC. I am thinking that maybe the Toroid is to 
>large to accomplish breakout given my available power level. I am going to 
>make a 13.5" Toroid from the same material tonight and give it a try.  I 
>was thinking that if it has all that power in the topload but can't 
>breakout from the toroid that it has to go somewhere and thus I get the 
>arcing.  I tried changing the hieght and the coupling but had the same 
>results without a nail for a breakout point.  Hopefully the change in 
>toroid size will solve my problems. I would love to hear others opinions 
>on this problem.  I read on the archives that the toroid hieght should be 
>equal to the secondary diameter as a general rule so I will check that at 
>the same time.
>
>Emmett
>
>
>>From: "Tesla list" <tesla-at-pupman-dot-com>
>>To: tesla-at-pupman-dot-com
>>Subject: RE: First Light but I have a Problem
>>Date: Sun, 14 Dec 2003 19:43:07 -0700
>>
>>Original poster: Thomas <tom-at-pwrcom-dot-com.au>
>>
>>Emmett, any discharge you see at the top of the secondary is not good. It
>>will decrease the spark length from the toroid, and possibly damage your
>>secondary windings.
>>
>>You need to lower the toroid closer to the top of the secondary.
>>
>>Tom.
>>
>> > Original poster: "Emmett Secrest" <secrest2032-at-msn-dot-com>
>> >
>>_snip_
>>
>> >My problem is that when I remove the nail form
>> > the surface of
>> > the Toroid I get some arcing from the top of the secondary
>> > column.  I have
>> > a PVC adapter on the top of the secondary that reduces it
>> > from 4" to 2"
>> > with a piece of 2" PVC elevating the toroid about 4" above
>> > the windings on
>> > the secondary.
>>
>>_snip_
>
>
>
>