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Re: Hosfelt snubber caps



Hi,
    I also have a large amount of those GE snubber caps, and it just caught
my eye when Terry recommended to use 7 or more in series.  Is the 3000VDC
rating really that reliable?,because that could allow me to greatly increase
my MMC's capacity since they are set up for 10 strings of 14/string right
now (when they could be set up for 20 strings of 7/string?).   right now I
am assuming a safe rating of 1600VDC each.

Thanks~Dave w


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, September 08, 2000 8:47 PM
Subject: Re: Hosfelt snubber caps


> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
> Hi David,
>
> Those big puppies will take like 15 amps RMS each!  Overheating them with
> an NST is simply not an issue.  As long as you use at least 7 per string
to
> get the voltage, you will be perfectly safe.  If they screw down, you may
> want to figure out a way to easily change them around to different values.
>
> DigiKey (www.digikey-dot-com) sells 10 Meg 1/2 watt resistors (10MH-ND) for
> about two pennies each.  Use two in series across each of these big caps
to
> get the voltage standoff.
>
> Yours are the MMC caps the rest of us dream of ;-))
>
> Cheers,
>
> Terry
>
> At 06:24 PM 9/8/00 -0400, you wrote:
> >Hi Terry, all,
> >
> >I was just letting everyone know that I finally broke down and
> >ordered 60 of those 0.1 uFD, 3000 VDC snubber caps from Hos-
> >felt today,that was discussed on this list a couple of months ago.
> >I'm wanting to replace the current 0.018 uFD, 60 KVDC Chicago
> >Condenser single unit cap that I am currently using in my 15/
> >90 NST driven system as it seems very lossy and heats up in
> >a short order after the coil is turned on. I am also wanting to re-
> >do the primary and secondary coils for a more efficient design
> >(I guess I am pretty much rebuilding the whole coil). Anyway,
> >I have a few questions to place on the list regarding the use of
> >these caps as an MMC.
> >
> >First, I was thinking of going w/ 4 strings of 15 (60 total) for a
> >total value of 27nFD -at- 45 KVDC. This will be my 1st real at-
> >tempt -at- a MMC cap and I was wondering if 4 strings of these
> >would be enough to handle the current of a 15/90 NST bank?
> >Without going into the mathematical equations, I figure on ~
> >5 nF per 30 mA as resonant for NSTs. So, I am figuring 27 nF
> >should make for a LTR cap setup for the 15/90 NST?
> >
> >Also, I was hoping someone could suggest a good source for
> >1/2 or 1 watt, 10 meg bleeder resistors (preferably some local
> >jobber like Radio Shack). Thanks in advance for your answers.
> >
> >Safe coiling,
> >David R.
> >
>
>
>