Re: Awsome first light !! but...

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

Original poster: "Edward Wingate by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ewing7-at-rochester.rr-dot-com>

Tesla list wrote:
> 
> Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Gary.Lau-at-compaq-dot-com>
> 
> Hi Ed:
> 
> To your question about current limiting my primary - The primary coil IS the
> current limiting component.  Whenever the main gap fires, the tank current
> is limited by the primary inductance.  Discharging a cap through a dead
> short and through a primary coil are two very different experiences for a
> cap.  In one case it is inductively limited, in the other it's limited only
> by the arc resistance and ESR & ESL of the cap.
> 
> I have no direct experience with capacitor death due to over-currents but
> it's not hard to see that the current pulse will be tremendously greater for
> the case without current limiting.  Since over-current is a failure mode for
> pulse caps, it seems prudent to soften the blow.
> 
> As an addendum to my original post, I probably should have pointed out that
> I was speaking mostly for the case of using static gaps.  When running an
> RSG as is the case with you, the RSG alone will NOT limit the maximum cap
> voltage.  All RSG's should have a static safety gap in parallel with them,
> and this will then limit the maximum cap voltage, AND it will be inductively
> current-limited.
> 
> Regards, Gary Lau
> MA, USA

Gary,

I have run 1 and 2 turn primaries. Have you ever measured the discharge
current from a cap into a 1 turn primary? Or the discharge current
through a safty gap set at one inch and wired with #18 wire? 

As I have stated on many occasions, the safty gap is just that, and is
not supposed to fire unless there is a problem, and if and when there is
a problem, you shut the system down.

Ed