Re: Why does running an NST on an async gap kill it?

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

Original poster: "colin.heath4 by way of Terry Fritz <teslalist-at-qwest-dot-net>" <colin.heath4-at-ntlworld-dot-com>

hi all,
         i have experianced similar with diodes on a twin mot system with
voltage doubler.
if the safety gap fired a few times it would destroy the diodes
same stress different component.
cheers
colin

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, August 11, 2003 5:12 PM
Subject: RE: Why does running an NST on an async gap kill it?


 > Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<gary.lau-at-hp-dot-com>
 >
 > Safety gaps should be applied only in parallel with the main gap and/or
NST
 > secondary.  Prior to firing, the main gap sees exactly the same voltage as
 > the cap does.  The capacitor does not ever see a voltage that exceeds what
 > is across the main gap.  So a safety gap across either the cap or the gap
 > will be equally effective at clamping an overvoltage condition.
 >
 > But, the vital difference is that when the safety is across the gap,
should
 > it fire, the energy from the cap will be transferred to the primary and
 > secondary circuits, just like a main gap discharge, which is just fine.
If
 > the gap were across the capacitor, there is nothing to limit the discharge
 > current except the very low impedance of the arc, and the cap will see
VERY
 > unhealthy discharge currents.
 >
 > Gary Lau
 > MA, USA
 >
 >   > Original poster: "Mudford, Chris by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <chris.mudford-at-agresearch.co.nz>
 >   >
 >   > Hi Gerry
 >   >
 >   > In what configuration would one set a safety gap across an MMC
 >   > capacitor?
 >   >
 >   > Cheers, Chris (NZ)
 >
 >