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Re: Top Toroid
At 11:15 PM 1/31/97 -0700, you wrote:
>> Subject: Re: Top Toroid
>> Subject: Re: Top Toroid
>> >Subject: Re: Top Toroid
>
>Subscriber: huffman-at-fnal.gov Fri Jan 31 23:10:02 1997
>Date: Fri, 31 Jan 1997 09:50:41 -0600
>From: huffman <huffman-at-fnal.gov>
>To: tesla-at-pupman-dot-com
>Subject: Re: Top Toroid
>
> [The following text is in the "ISO-8859-1" character set]
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>Hi Group,
>OK I have a capacitance meter and several toroids, can they be measured
>directly or do you put them on top of an inductor and from the freq. shift
>calculate the capacitance?
> __ __
>/ \ / \
>\__/ \__/ does the capacitance change much if the toroid
> __ ___ __
>/ \
>\__ ___ __/ is filled in the middle. I would think the E-field looks
>similar.
>
>Dave Huffman
>
>
David,
Most meters are not stable or accurate at the lowest range. I tend to use a
carefully controlled method of measuring "near" isotrpoic capacities. We
give full details on one of our tapes.
I hang the terminal from a nylon filament from the roof and measure the 1/4
wave frequency of a coil and associated wire lead to the toroid, (minus the
toroid) first. Next I find the combined frequency and calc backwards to
find the true capacitiy added to the circuit. It never jibs with any
prescribed engineering calc, EVER! For best accuracy make sure that the
toroid is suspended at least ten times its major axis from the nearest
worldly item. (ground, the dog, tables, etc.) For apartment dwellers this is
not realizable. This assures that close to normal, fully developed,
capacity of the object will be realized.
Richard Hull, TCBOR