Re: Maxwell AC vs. DC ratings

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

Hi Ed,

On 5 Apr 2004, at 12:04, Tesla list wrote:

 > Original poster: Edward Wingate <ewing7-at-rochester.rr-dot-com>
 >
 > Tesla list wrote:
 >  >
 >  > Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com> >
 >  > Hi Bert,
 >
 >  > I never realized these caps were so fragile!!  I sold those two I
 >  have from > that Lichtenberg figure experiment (wouldn't have
 >  worked...) to Kreso and > we were wondering about this.  I have
 >  always played with MMCs, not > commercial caps ;-) > > Cheers, > >
 >        Terry
 >
 > Terry,
 >
 > Commercial pulse caps aren't "fragile", they simply need to be
 > properly speced for the intended use and then operated within those
 > specs. I have certainly never had a commercial cap fail from
 > "overcurrent" as your recent MMC postings seemed to indicate. Actually
 > I've had only one commercial cap fail in 15 years and that was due to
 > a manufacturing defect in one section. The company built me a new one
 > for free even though the warranty period had run out!
 >
 > MMCs are OK for "playing", commercial caps are for more serious work!
 >
 > Regards,
 >
 > Ed Wingate RATCB

I second what you say but note that in my experience, a
conservatively designed MMC will do just as well as commercial cap
(and funnily enough) costs about the same to build to the same
ratings. I think the real problem with MMCs is people underdesigning
and expecting to get breathtaking performance and reliability for a
fraction of the cost. Free lunch.

Malcolm