Re: toroid question

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Allan,

We studied this and the distance from the secondary is far enough to vastly
cut down on the coupling.  Also terminals are not the greatest high
frequency low voltage conductors and they tend to look a lot like
resistors.  There is a little loss but far too small to noticed.

Cheers,

	Terry


At 04:52 PM 1/27/2002 -0800, you wrote:
>It has occured to me that using a toroid with no conducting material in the
>center in effect places a
>shorted turn in the magnetic field and would cause
>very high current to flow. Upon testing my theory on
>my coil, I found very little difference in the two types.
>I would like to know why the shorted turn toroid doesn't
>consume great quantities of power.
>
>any ideas?
>
>allan
>
>----- Original Message -----
>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: <tesla-at-pupman-dot-com>
>Sent: Wednesday, January 23, 2002 5:56 PM
>Subject: Re: toroid question
>
>
>> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
><Mddeming-at-aol-dot-com>
>>
>> In a message dated 1/23/02 10:15:48 AM Eastern Standard Time,
>tesla-at-pupman-dot-com
>> writes:
>>
>>
>> >
>> > Hi Godfrey,
>> >
>> > in my opinion there is no need to deal with toroids, whose hole in the
>> > center is <=zero, or very small, relative to the outer diameter. The
>> > outer diameter is probably choosen in a relation to the size of the
>> > secondary or to sparklength, in order to get a nice "shielding effect"
>> > for corona (i remember John Freau proposing D.toroid=~"desired
>> > sparklength"/2.5), or considering the whole TC in a Pspice-simulation
>> > for output power and voltage. The diameter of the "cord" should be in a
>> > relation to the secondary outbreak-voltage (remembering again John:
>> > d.toroid = "desired sparklength"/10, as a start). But the ROC of the
>> > torus will never be really perfect, even if having a spun toroid. And as
>> > soon we get breakout, the toroid will no more be smooth anyway, 'cause
>> > the streamers and sparks are like "needles", and the jon-cloud may be
>> > adding capacitance. Personally i try to choose a ratio of diameters, -
>> > not at all scientifically - , which gives me a good feeling about
>> > proportions. And this is not one with zero inner hole radius, which
>> > might typically be not much less than the cord radius.
>> >
>> > Anyway i'm keen to see your approximation to the "true capacitance" of
>> > an isolated toroid, probably with an estimation of accuracy. This seems
>> > to me of great value, even, if after all, either we may find Bert Pool's
>> > formula just good for our purpose or utilizing a more elaborate formula
>> > in our calculations (i.e. spreadsheets).
>> >
>> > Cheers,
>> >
>>
>>
>> Hi Godfrey, Kurt, All,
>> Capacitance is also affected to some degree by what's in the toroid's
>hole. A
>> toroid with a "pieplate" center will have somewhat different capacitance
>than
>> one with a "spoked wheel", which will be different from one with 3 plastic
>> "struts", etc.
>> Matt D.
>> G3-1085
>>
>>
>