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Re: mmc calculator

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Bob,

At 01:37 AM 2/28/2001 +0000, you wrote:
>Hi All,
>    After my mishap with my cap on Sunday I have decided to build a
>bigger one.:-)) I have a few questions. When using  Barts java
>calculator I am a bit puzzled about the" primary circuit resistance"
>box. Do you use the single cap internal resistance calculation and
>multiply it by the number of caps?. It looks to me as if there is a
>trade off between  the voltage rating and the ESR. I have 340 of the ERO
>caps that Mike got. 0.068uF 1500 volts. I know someone did find the spec
>for these but I can't find it at the moment. I was going to go for  18
>strings 0f 18 caps. If I use the single cap resistance calc this comes
>out at 6.9 ohms. Which the program says is very good. Have I got this
>right? I would like to use the same cap when I change to a DC supply. Is
>the voltage calc the same.?
>bob golding

The "primary circuit resistance" is sort of an arm waving guess about the
equivalent resistance of your primary circuit loading.  I usually put it at
3 ohms which is usually pretty close for most coils.  It cannot be easily
measured.  However, it is a little conservative so 3 ohms should work fine.
 The actual resistance of the capacitor is calculated based on the
frequency and dielectric loss for polypropylene as used in capacitors.
That is directly borrowed from WIMA data sheets (they are all the same).
The base formulas are in the document bellow for reference.



	Terry Fritz