Re: Doorknob Caps

Subject:  Re: Doorknob Caps
  Date:   Sun, 15 Jun 1997 04:32:46 +0500
  From:   "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
    To:   Tesla List <tesla-at-pupman-dot-com>

On Wed, 11 Jun 1997 19:31:41 -0700 (PDT) Edward V. Phillips
<ed-at-alumni.caltech.edu> wrote;

>> "I would think the resistive losses in a capacitor is going to be
>> insignificant, the reactance losses are another story, remember
>> were dealing with A.C."

>         Plenty high enough to heat the capacitors.  I am using
> 3000 uufd, 30 kV doorknobs here and can only run them for a
> minute or so at a time, because of the self heating.  The series
> resistance is very low, but the loss due to the ceramic dielectric
> is large."

Ed what you are talking about is dialectric heating and it has 
nothing to do with resistance (D.C. resistance) if you were to put an 
oh meter across that capacitor it would probably read in excess of 
100 meg ohms! The dialectric losses or power factor losses as they 
are sometimes called are due to the dialectric absorbing the R.F.

>> "Your also forgetting that inductors also have
>> hysteresis losses."

>         Not air core inductors such as we use for primaries.  The
> losses in the windings are insignificant compared to the loss in
> the primary gap and the secondary discharge, at least in my opinion.

True air core coils and transformers don't suffer from hysteresis 
losses, but that comment was made in terms of the generic 
ter "inductance" which included iron core inductors.

BTW a comment to all and not directed to anyone specificaly. Far too
often on this list people are using specific terms in vauge and 
generalized ways like calling dialectric losses and hysteresis losses
resistance losses! Each of these terms has a specific meaning and if 
we blurr these definitions our work will cease to have any scientific 
value. Lets try not to over simplify for convience, and stick with 
the official definitions.


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