Re: Good cheap large caps?

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

Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz>

Team
Gary Makes a very valid point
Not ALL MMC designs are best using 0.33uF/1600V

Where low C and higher V design is called for then using 0.15uF/2kv will be
better or other low C high V caps

As you will see in a previous posting the bigger cap makes sense for the
bigger MMC. As a person playing with medium power coils my MMC focus is
around the 100nF/25kv area
Best
Ted L in NZ
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, June 14, 2002 6:17 AM
Subject: RE: Good cheap large caps?


> Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Gary.Lau-at-hp-dot-com>
>
> There may be a false economy in just looking at the highest joules/$ for a
> component cap.  Using .33/1600V caps, a string of 13 will give you a nice
> .025/20.1kV MMC.  But if you are using a smaller NST and you're shooting
> for a .006uF cap, you'd have to string together 55 .33/1600's.  True, your
> cap would be rated at 88kV, but this is just a waste of caps.
>
> A .006uF cap could alternately be made of 25 .15/2000 caps.  It too would
> be over-rated voltage wise (50kV), but would use fewer caps.
>
> Or, a .006uF cap could be made of ten .056/2000 caps, resulting in a
> .0056/20kV MMC.
>
> What costs less:
> 55 .33/1600 caps,
> 25 .15/2000 caps, or
> 10 .056/2000 caps?
>
> I also am uncomfortable with the thought of using just a single string of
> caps, as the entire primary current must be carried by every cap.  Better
> to use multiple strings of smaller caps, dividing the current so many
ways.
>  But I've not gone through the numbers to prove that this is a problem.
>
> Gary Lau
> MA, USA
>
>  -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Thursday, June 13, 2002 1:44 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Good cheap large caps?
>
> Original poster: "Christopher Boden by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>
>
> I'd like to know which really is the better buy, if there is a signifigant
> interest I can get the 942C16P33K, and I can sell them for $2.50 each
> (that's what they cost from the factory). I can get 238pcs within a week
if
> there's enough interest. Someone organise a Bulk-Buy and I'll supply them
to
> you. Though, after all the work we've done for the .15's I still believe
> that the .15uF cap is a better buy. Someone show me HARD FACTUAL NUMBERS
> proving which cap is best, then I'll see if we add the new one or not.
>
>
>
>
>
> Christopher "Duck" Boden Geek#1
> President / C.E.O. / Alpha Geek
> The Geek Group
> www.thegeekgroup-dot-org
> Because the Geek shall inherit the Earth!
>
> >Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> ><tesla-at-paradise-dot-net.nz>
> >
> >The CDE 942C16P33K 0.33uF 1600v is pretty good
> >(CDE = Cornell Dubilier Electronics)
> >
> >My current order from Richardson Electronics is USD$2.68/each for an
order
> >of 27
> >
> >This is the best $/nF/kv with very high pk I and dv/dt that I can find
and
> >I
> >believe it to be a MUCH better buy than Geek Caps 942C20P15K
(2000v/0.15uF)
> >For the slightly smaller V rating and higher Ipk the extra few caps per
> >string are more than paid for by the DOUBLE capacitance size
> >
> >Food for thought, If someone disagrees luv to hear from you with
reasoning
> >Best to list
> >Ted L in NZ
>
>