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Re: doorknob capacitor



Tesla List wrote:
> 
> >From ed-at-alumni.caltech.eduSun Sep  1 21:59:48 1996
> Date: Sun, 1 Sep 1996 11:42:18 -0700 (PDT)
> From: "Edward V. Phillips" <ed-at-alumni.caltech.edu>
> To: tesla-at-pupman-dot-com
> Subject: Re: doorknob capacitor
> 
>         I think Richard is being a little pessimistic here.  I have
> been running three of what sounds like the same capacitor here for
> about a year (at most a minute at a time, to be honest) and they seem
> to work OK.  They do heat up, which will surely result in breakdown,
> and the capacitance is temperature sensitive enough that the change
> in coil tuning with (even room) temperature is quite appareciable.
>         If that's all I had I'd use it, while plotting to get something
> better.  I have a couple of the C.P. capacitors here which I have yet
> to fire up, but I expect great things out of them.
>         By the way, I should have mentioned I'm using the doorknobs
> with a 12 kV, 60 ma transformer running about 6 amps primary current.
> Getting  good (at least for me) results, 24" plus sparks from a 3" OD
> by 16" high coil resonating around 270 kHz.  By no means optimum, but
> the results are good enough to satisfy visitors and allow for various
> toroid experiments which completely verify the benefits reported by
> the Richmond Richard.
>         My nephew, who teaches high school science down near San Diego,
> also bought about 30 of the 4700 mmfd (most of them are nearer 3200,
> by the way) capacitors from the same source I did, and his students
> have been having a lot of fun making various coils, all powered with
> the same 12 kV, 60 ma transformers of which George found an almost
> unlimited, free (to high schools, at least) source.
>         By the way, having popped a few doorknobs at various times, I
> can verify the loss of silver.  However, for at least two of the capacitors
> which failed, I believe it started with a break in the silver due to
> the fact that the studs were not secure in the plastic potting, and probably
> rotated a bit which broke the original continuity and provide a site
> for arcing.  As soon as that started, of course, the silver was indeed
> "eaten away" by the very large surge currents.
> For what it's worth,
> Ed Phillips


Ed-

Might that source have been the Highway Company in Oceanside?

I got several of those 'hocky-pucks' and found several with loose
terminals - took 'em back and replaced them. Seems that was a common
problem, but since the place had a million of 'em....

- Brent