Doorknob Cap Current Handling was RE: New Pix (caps across gaps, gaps across caps)

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

Original poster: Zagarus Rashkae <arbitrarily_random-at-yahoo-dot-com> 

Hi Gary, All,

I think doorknob capacitors were designed with insane
discharge currents in mind. I cracked a TDK UHV series
doorknob cap open once (waste of money :/ ) and it had
a brownish ceramic dielectric (IIRC, it's been a
while) and the electrods on either side were flat and
about 1/8 inch thick! I guess it was silver plated
copper or something of the sort. I have heard of
currents of >60kA from a small doorknob bank.

Regards,

Chris

--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "Lau, Gary by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <gary.lau-at-hp-dot-com>
 >
 > Hi Weazle:
 >
 > I notice that you have a couple of doorknob caps
 > across your hyperbaric
 > gap.  From the perspective of these doorknobs, with
 > every bang of the gap,
 > the full charge in the doorknobs is being directly
 > shorted.  While this may
 > shunt some HV/HF noise generated by the gap, it's
 > not at all healthy for
 > the doorknobs, which are not known for their ability
 > to handle high
 > discharge currents.  If the goal is to protect the
 > power transformer, then
 > putting some HV resistors (i.e. an R-C filter)
 > between the gap and
 > doorknobs would make the caps much happier!
 >
 > But to switch sides and play the devil's advocate
 > for a moment, I wonder if
 > there is any benefit as far as improving quenching
 > or reducing gap
 > on-resistance, afforded by having a cap in parallel
 > with the main gap?
 >
 > Gary Lau
 > MA, USA
 >