Re: What caused capacitor failure?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Hollmike-at-aol-dot-com>

Brett, 
  My guess is that you were running too close to resonant mode, which will
cause a much higher voltage to appear on the caps.  If you had used all the
strings and tuned your primary coil accordingly, you probably would still be
having much fun. 
   The peak voltage your caps experience would be 1.414 time the RMS voltage of
your transformer output.  Already, you were in trouble.  If  you run in
resonant mode, the voltage can be several times higher, which can kill not only
your caps, but your transformer as well.  You should use a cap that is at least
1.5 times the impedance(resonant) match.  You have heard of the LTR cap, no?   
You can use more than that even -  up to about five or six times the value, but
of course, your system has to be designed for that in order to have enough
primary inductance to be tunable.  It is a balancing act, to say the least. 
    
Mike 

>
> How can I prevent this problem in the future?  Needless to say, that was an 
> awfully expensive 10 minutes (although immensely satisfying).  I'd like to 
> figure out what I can do to prevent this failure before trying it again. 
>
> Thanks in advance for your help. 
>
> Brett 
>
>