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Re: The death of a classic



Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <f-h-at-c.dk>

Malcolm

Gap voltage is 32 kV (most of the time, but I am sure I`ve hit it with
up to 45kV for quite some time as well) BPS is 300
The charging sequence can be seen here:

http://home5.inet.tele.dk/f-hammer/tesla/museum/setup/probe.jpg

The resistors are Phillips VR37 types, they should be good for 3.5 kV
The caps are Phillips kp/mmkp 376, the data are here:

http://www.wimshurst-dot-com/kp376.pdf

but keep in mind, that the caps are a special order, where they are
packed in the next smaller pitch casing as thestandard ones. I got
them because the distributor was stocking them at the time for some big
manufacturer, who had payed for the special small package. they were
what I coulg get at the time, 3 yrs. back. Perhaps you recall the
frenzy  we were all in, excited about this new kind of tesla cap.
Anyway, I suspect it has a slightly thinner dielectric than the standard
version.

I took a couple of hi-res pics of the opposite strings, they reveal the
construction well, 

http://www.wimshurst-dot-com/hotend.jpg

http://www.wimshurst-dot-com/coldend.jpg

and give a clue to the failure, if it is not starting from a cap:
One of the strings should have been reversed, so that it was a mirror
image of the other, that way, the potential along adjacent nodes would
have been the same. This way, there is a potential difference equal ti
the total voltage divided with 20. Now, if one single cap gave up, there
would be twice that. Perhaps a combination of the 2?
I didn`t pay attention to these things at that time, I simply didn`t
zoom down to that level 3 years back.


Tesla list wrote:
> 
> Original poster: "Malcolm Watts by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
> 
> Hi Finn,
>         I expect you have done this repeatedly but would you mind
> posting again the spec for your MMC? Also, the transformer/gap
> voltage and breakrate.
> 
> Thanks,
> Malcolm