Re: Conserving Q ? /Faraday

[brian whatcott <inet@INTELLISYS.NET>]

At 11:11 11/26/98 +0100, Ludwik wrote:
> ... in case somebody does want to verify our data.
>
> 1) Material was Lexan....

> 2) Each measurement was made after 3 minutes at 1000 V. We discharge
>    the dissectable capacitor, remove the top aluminum block and bring
>    pieces to the electrometer on another table, one after another. The
>    first sample is in the Faraday cup after about 25 seconds, the second
>    10 to 15 seconds later. (The rate of loosing charge is very slow, neither
>    A nor B loose more than 5 % of Q in couple of minutes. Clean the
>    "cork" of your old electrometer very well to arrive to this)
> ...
> Ludwik Kowalski
It would be interesting to know the plate dimensions.
 And I recall, the phenomenon of charge recovery takes some time to
manifest itself. This effect has been responsible for some nasty shocks
(sometime AFTER shorting out a high-value capacitor). However, I seem
to recall the modern recovery anecdotes usually involve electrolytic
capacitors - so this is possibly a different effect.

 One might consider a control series with increasing wait times after
polarization before testing the available charge.
 From the little I recall on this effect, I'd expect a maximal recovery
after some optimal latency time: perhaps involving a balance between
leakage and acessibility.


brian whatcott <inet@intellisys.net>
Altus OK