Re: Maxwell AC vs. DC ratings

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


According to Bob Cooper, Maxwell's chief cap engineer, the usual suspect is
surface tracking at the sharp edge of the plate foil.  Second in line is
corona within voids in the dielectric.

Dr. Resonance
 >
 >  > I do wonder "what wears out" in them??  Might just be pure mechanical
 >  > stresses as the high current shots pound them.  In that case, a lower
peak
 >  > current Tesla coil my not wear them at all.  ESR just burns them up but
 >  > does not really "wear" them.  Dielectric damage due to ionization seems
to
 >  > be a big factor from reading data sheets on them where they are so
worried
 >  > about voltage reversal.  I am not sure...
 >
 >  >From what I've learned and read, electrical (corona) and mechanical
 > stress eventually weaken the dielectric to the point of failure. I'm
 > guessing that corona is what you are referring to as ionization. Pulse
 > capacitors lead pretty stressful lives.
 >
 > Ed Wingate RATCB
 >
 >  > Cheers,
 >  >
 >  >          Terry
 >  >
 >  > >Ed Wingate RATCB
 >
 >
 >