Re: Maxwell 37667 pulse caps

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Chip,

I can't speak from personal experience on these caps, but
it seems that the general consensus on these is that they
are good for small to medium powered coils as long as you
keep the primary circuit voltage <15 kV. There have been
a few "early deaths" recorded with these caps when operated
with 15 kV NSTs. Of course, keep in mind that most people
overdrive their transformers with 140 volts in from their variac
turned all the way up, so that's like 17.5 kV RMS input. The
DC voltage rating of a commercial pulse cap should be at
least 2.5x the maximum AC RMS voltage that it will be seeing,
so running one of these with a 15 kV NST is pushing them on
the "ragged edge" of their designed voltage limits.
I don't think there's been many problems with these if they were
ran with NSTs of 12 kV rating or less. I'm sure other with experience
with these type of capacitors could comment on this. The 500 pps
rating means just that - they are ated for 500 pps at their rated voltage.
Most of the Maxwell 31xxx series capacitors are rated for just 1 pps,
but most of the 37xxx series are rated between 100 and 1000 pps.

David Rieben


----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, November 21, 2006 7:56 PM
Subject: Re: Maxwell 37667 pulse caps


> Original poster: "Chip Ford" <chipford@xxxxxxxxxxxx>
>
> So you are saying even though Maxwell rates these caps at 500 PPS (pulses
> per second), They are really one pulse per second caps? Does everyone
agree?
> Has those that have used these caps been disappointed. Would I be better
off
> listing them on ebay and selling to the next sucker before I destroy them?
>
> ----- Original Message -----
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Tuesday, November 21, 2006 2:22 PM
> Subject: Maxwell 37667 pulse caps
>
>
>  > Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>
>  >
>  > Much has been descussed concerning the infamous 37667 maxwells.
>  > I think the general consensus is that these are 1 pulse/sec caps, and
>  > therefore are a bad choice for coiling. Many list members report
>  > blowing them up. I bought 5 of them a few years ago in preparing
>  > for my big coils. I ran a pair in series with an NST powered coil,
>  > and had no problem, most likely because I way underrated them.
>  > Anyway, since another 'new' coiler just purchased a couple, it might
>  > be a good idea for Terry, to post a warning on the list index about
these
>  > caps, so more of us don't unknowingly buy these, only to blow
>  > them up. What do others think?
>  >
>  >
>
>