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Re: MMC Protection SGap current limit
Hi Shad,
On 14 May 00, at 19:28, Tesla List wrote:
> Original Poster: "sundog" <sundog-at-timeship-dot-net>
>
> Good afternoon everybody! And Happy Mother's Day!!!
>
>
> Possibly a "duh" question, but I'll ask it anyway...
> There seems to be a lot of concern about the cap saftey gap
> firing and the high-amp pulse toasting the caps....I am looking at
> my nst, my caps, my main gap (static gap of 8 2" dia copper pipe),
> and my primary. My system tunes around 5.5-6 turns out on the
> primary, and that isn't much resistance or inductance. What is so
> different from the main gap discharging than the saftey gap?
> There's no resistors in line with the main gap...and my DMM says
> that the resistance of 1 side of the spark gap, across the primary,
> to the other side is moot (says .9 ohm), it's pretty much a dead
> short. Yes, it rings down, but the energy per bang is decreasing.
> So I give...what makes the firing of the saftey gap so much more
> dangerous than the firing of the primary gap? And if that's the
> case, I like the idea of putting the saftey gap in parallel with
> the main gap, and set to fire a few KV higher...I'm assuming most
> of this deals with rotarys instead of static gaps, where missing a
> firing is more likely. If firing the main gap, through the primary
> is safe, why not just coil a helix of tubing, say, 35-40 ft, in a
> box, seal it, and run that in series with your saftey gap instead
> of a resistor? Definately cheaper, and should look identical to
> the caps as the primary you're already pushing (for the most part
> at least)....Just a my $.02.....
> Shad
What's different is that the main gap has an inductor, namely the
primary coil in series with it. The surge impedance of the coil limits
the peak circuit current.
Regards,
Malcolm