Date: Thu, 17 Feb 2011 15:56:10

Author: Dale E. Stille

Subject: Re: Tin Foil Capacitor

Post:

Paul,

Actually, for us in Iowa, the humidity at present is around 10 to 15
percent. My pith balls will repel for hours to days now, so I know that
is not my current problem.

Thanks,
Dale

Paul Nord wrote:
> Dale,
>
> You should have tried it last week. Much too warm today. You probably need to be quick or do this with very low humidity.
>
> There were a couple of things said in that article that confused me. Perhaps the experts can shed some light on this. In the last paragraph the author mentioned that this effect wouldn't work if you had insulating layers between the rolls of foil. Though he seems to imply that he has not tried this. Would a coil of a single foil with a insulating layer have a higher capacitance than a conducting tube? Wouldn't the charge simply move to the outside surface?
>
> Second point of confusion. The entire demonstration is intended to infer that a charged rod has a lower capacitance than a flat sheet. Yet the author suggests that this would not work if the foil were wrapped on a conducting rod. Or was he only intending to say that this wouldn't work if the rod were grounded?
>
> Paul
>
> On Feb 17, 2011, at 3:24 PM, Dale E. Stille wrote:
>
>> Tappers,
>>
>> Anybody do the "Tin Foil Capacitor" demo by Frank Noschese that was mentioned on page 621 of the Dec. 2010 TPT. Basically you have a roll of tin foil connected to a electroscope. When you charge the electroscope and then unroll the tin foil the voltage goes down, and when you roll it back up the voltage returns to the original value.
>> My problem when I try to set this up is the voltage leaks off this at about 1000 V. per minute which make it unusable for me. I have narrowed it down to the fact that the voltage is leaking directly off the tin foil. I imagine there is some trick to making this work like the video that went along with the article but I ain't catching it.
>> Can somebody clue me in??
>>
>> Thanks,
>> Dale
>>
>
>


From tap-l-owner@lists.ncsu.edu Thu Feb 17 16:59:53 2011

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