Re: Good & Bad Maxwell Caps, MMC questions?

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

Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>" <presence-at-churchofinformationwarfare-dot-org>

None of the DC pulse caps from Maxwell are meant for AC usage, or even
extended DC usage as filter caps. The load they see from a Tesla Coil is
going to be "very" AC and bad for them no matter how rough and tough they
are for DC pulse duty.

KEN


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, July 16, 2001 12:16 PM
Subject: Good & Bad Maxwell Caps, MMC questions?


> Original poster: "Bill Vanyo by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<vanyo-at-echoes-dot-net>
>
> I just blew my Maxwell cap (0.06uF, 30kV, catalog #37321 - type with
> terminals on top).
>
> I was never sure whether this was a good cap for Tesla use.  I've seen
> guidelines in the past that said those with the terminals on top
> (instead of on opposite sides) generally didn't have a long life.  It
> worked great for a while, but now it's dead (cap makes a sort of
> fizzling sound when I first power up).
>
> Can anyone confirm that this is indeed not a good cap to use, or is this
> what I could expect with any Maxwell cap?  And if mine was bad, which
> are good?  The reason I'd like to get another Maxwell (if I can find a
> more reliable one) is that it's "plug-and-play" - no assembly required,
> and compact.
>
> Are MMC's really any better?  To what extent are they "self healing"?
> To build a really sturdy MMC with the geek group caps (942c), for use
> with 15/180 NST (three 15/60's), what is the minimum string length and
> number of strings to handle the voltage and current they'll see?  I can
> adjust upwards to get my desired capacitance, which is between 0.06uF
> and 0.045uF --- 0.06 because that's what I was using and it worked,
> 0.045 because that's the "right" LTR value for 15/180 with a static gap,
> but I don't know (I haven't calculated yet) if my primary has enough
> extra turns that I'd still be able to tap it in tune with 0.045 (I
> currently tap around 7.5 with my biggest topload, and have 10 turns).  I
> understand that the strings need to be of adequate length to handle the
> voltage (though I'm not sure what that length is to get a long MMC life
> with 15kV AC in tesla coil use).  Am I right that there is also some
> minimum number of strings needed for adequate current handling (180ma,
> in my case)?
>
> BTW (and I'm not sure, but I think I've heard this reported before), my
> coil seemed to be performing better than it ever had shortly before it
> died.
>
> Thanks,
> -  Bill Vanyo
>
>
>
>