Re: mmc testimonial

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Greg,

On 17 Feb 2002, at 21:08, Tesla list wrote:

> Original poster: "Mr Gregory Peters by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
> 
> Before I make my big (over 100 caps) mmc for my pole pig coil, I 
> decided to make a smaller one for my NST powered coil to see how well 
> it performed. Here is my story:
> 
> CAPS ARE 0.1uF 1500VDC ARCOTRONICS 72 SERIES CAPS.
> 
> I always like to use the tesla "equidrive" tank circuit whereby the 
> caps are placed on both sides of the primary. On each side of the 
> primary I have two strings of capacitors in parallel. There are 8 caps 
> per string. Therefore, in total I have 16 caps per string, and two 
> strings in parallel, for a little over 0.01uF (with 32 caps). I ran 
> this with my 15kV/90mA tranny setup for several minutes. I used my 
> airblast gap which provides excellent quenching at these power levels. 
> It performed well, with minor arcing over due to me not leaving enough 
> clearance between strings. I then hooked up 4x 0.01uF homemade poly 
> caps in series/parallel with the mmc cap for a total of about 0.02uF. I 
> hooked up my 11kV pig, current limited to about 4kW. If you use E=CV^2 
> you will see that the 0.01uF at 15kV and the 0.02uF at 11kV have a very 
> similar energy per bang. The beauty of the pig was I knew I could 
> provide enough current to fully charge the capacitors. 
> 
> I ran this system for 10 minutes flat (timed, not guessed) producing 
> over four foot sparks. The primary got very hot. The MMC caps had 
> warmed ever so slightly (barely detectable) and the big poly caps had 
> not risen at all due to so much oil. I am very impressed with the 
> ability of the mmc caps. They weigh probably 10 times less than the 
> poly caps, they self heal, self discharge and don't leak oil. I was 
> skeptical of their ability at first, but they really are great and cost 
> a lot less than the 4 poly caps I made (taking into account plastic, 
> foil, pvc pipe, oil, etc). Many thanks go out to Terry for his 
> excellent web page.

I too use the Arcotronics caps. I have to warn howevr that they are 
probably *not* self-healing as they are foil-film. AFAIK, the only 
self-healing models are metallized-film. For those particular caps, I 
run about 40Amps pk /string which has proven to be bullet-proof at 
rep rates up to 200.

Regards,
Malcolm
>