Re: toroid parts...

At 01:53 AM 8/17/96 +0000, you wrote:
>From ntesla1-at-vm.sc.eduFri Aug 16 13:35:46 1996
>Date: Fri, 16 Aug 1996 07:15:55 -0300
>From: Dan Kline <ntesla1-at-vm.sc.edu>
>To: tesla-at-pupman-dot-com
>Subject: Re: toroid parts...
>>>I think you will find that whatever you use to reinforce the center of
>>>the toroid will make the entire assembly very stiff. I have used
>>>masonite and just plain 1/8" plywood with excellent results. I use a
>>>bead of alumunum glue on both sides of the center piece to firmly attach
>>>it to the duct and let it dry well. Then I connect the center mounting
>>>hole to the toroid using aluminum tape with adhesive on one side.
>>>Good luck
>>Hi All -
>>Has anyone tried to test these duct toroids for capacitance to compare them
>>with spun aluminum toroids? They appear to have very low capacitance.
>>John C.
>What...You're selling spun toroids too? C'mon...;) 
>Since all of the charge on an isolated capacitance is on the surface of the
>capacitor, assuming uniformity and smoothness, one would think that the
>Al-duct capacitors would be slightly *higher* in capacitance than a smooth
>toroid, simply because there is a greater surface area on the ducting. It's
>not like there are any sharp edges or corners to leak charge from, the only
>real possibility might be from the seam, where the two ends are joined. But
>careful construction should take care of that. Admittedly, there will be
>greater concentrations of electrons at the peaks of all the "ridges" (for
>lack of a better word), but as far as the entire electric-field density is
>concerned, I can't imagine the difference being more than a couple of
>pico-farads, again towards a *higher* capacitance. I supposed the
>capacitance could be lower on a really high-power system though...my largest
>has only been 3kW. 
No. I'm not selling toroids. I did get a chuckle out of that tho.

How about testing your toroid. A method is shown in one of my books. (Grin)

John C.