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Re: Success with PP Multi-Mini Cap

Hello all,

I am far from a expert, but the use of MMC for large disruptive Tesla
coils, would I think, be more inefficient, due to resistive losses?

Regards,

David Trimmell

At 07:04 AM 4/5/99 , you wrote:
>Original Poster: "Reinhard Walter Buchner" <rw.buchner-at-verbund-dot-net> 
>
>Hello Richard, all
>
>>Original Poster: Richard Hull <rhull-at-richmond.infi-dot-net>
>>
>>In some of our very earliest video reports from back in 1989 and 90 we
>>show how to make two different type of Tesla caps made up with
>> series strings of smaller polypropylene units under oil.
>>They work fine until you start throwing th' coals
>>to things.  Best for beginner systems under 2KW.
>
>
>Regarding your last statement: Why? I noticed that you have mentioned
>this a few times, but quite frankly, I donīt understand it and I canīt
>say
>I can agree with you.
>
>How (general scheme) were your MMCs constructed and why did
>you run them under oil? As I already pointed out to Ed Sonderman,
>the oil does nothing to help the MMC survive. I canīt agree with
>your last statement either (unless you used a single and very long
>string). If you use many series strings in parallel, the total primary
>current is divided up (pretty) evenly across all strings. Quick
>example of what I mean: Letīs say you are running a single string
>at 400W. Letīs further suppose the primary current is 40A. (Iīm
>just using these values for convinience). Now, if I upgrade my
>PSU to 4000W and design my MMC not as a single string, but
>as a 10 string device, I still get (roughly) a current per string of
>40A. So why should this MMC fail? I know the current wonīt go up
>(from one xformer to another) in such a linear fashion, but the point
>Iīm trying to make is another: If you keep the current PER series
>string low, than it doesnīt matter if you use a 500VA or a 5kVA
>xformer.
>
>The MMC has another advantage that no other homebrew cap
>has: It voltage versatility.
>
>Example:
>-------------
>Xformer: 7.5kV
>Needed cap: 10nF
>Caps: 10nF-at-1kV each
>Array: 10 strings of 10 caps each
>Joules: 0.5*10606^2*10*10^-9=0.56J
>
>Now letīs say I find a 15kV xformer. All I have to do is rearrange
>the caps for 5 strings of 20 each. The total capacitance drops
>to 1/4 of the original value. However, due to the square
>function in the Joule equation, the Ws stay the same.
>
>5 strings of 20 caps = 2.5nF.
>Joules: 0.5*21213^2*2.5*10^-9=0.56J (same as above)
>
>Of course, I COULD do the same thing with a rolled PE, but
>I would have to build additional ones. The MMC setup allows
>me to simply rearrange things, so that they fit. Meaning my
>"work" is limited only to a re-wiring scheme (easy and
>quick to do).
>
>
>Coiler greets from germany,
>Reinhard
>