Re: Capacitor energy experiment

[Bernard Cleyet <anngeorg@PACBELL.NET>]

Wrong!  It's dielectric absorption.
http://www.audience-av.com/on_capacitor_dielectric_material.htm

However, there is a relaxation time associated with the free charges that
must diffuse to the plates to pose the danger of shock.  Harnwell (Oh! I
love Harnwell) devotes > one p. to this.  He derives the time.  For mica
and petroleum oil it's ~ 2 sec.   Polyethylene, a few hours.

bc

Bernard Cleyet wrote:

> Early electrolytics were constructed of Al foil and an electrolytic that
> cause an Al2O3 film (anodize) when the cap. is formed by charging.  (AC
> will result in a nonpolar cap.)  Since the plates are not of the same
> material (polarized cap.) and they are connected by a conducting fluid,
> I expect that they make a chemical cell.  Not surprising they are a
> "battery".  I don't know about contemporary caps.   [I made them using
> baking soda.  If one uses an Al plate and a carbon rod in NaH2Co3? soln.
> the result is a high current rectifier.
>
> Some of the large storage caps (> 1 kV) are marked keep shorted when not
> in use.  I think the term is relaxation (of the dielectric).  I've never
> heard of this for electrolytics, but it doesn't surprise me.  They leak
> so much that it's not an ever present danger as with high Q high V

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