Re: Magnetic quenching.

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

Original poster: Sean Taylor <sstaylor-at-uiuc.edu> 

On Fri, 12 Mar 2004 21:33:06 -0700, Tesla list <tesla-at-pupman-dot-com> wrote:

>Original poster: John <fireba8104-at-yahoo-dot-com> Hi,
>   I was thinking the same thing but with a complex controller. The idea 
> is that a short burst of high current (large value cap?--include diodes 
> to attempt to stop ringing) is supplied to a electro-magnet every half 
> cycle in order to "trigger the gap".This idea stems from a former post 
> where breakdown voltages were given, showing a lower breakdown voltage 
> with magnetic flux applied. Also, if is not to complex,  a current 
> detecting device could be used to tell when the first notch is reached, 
> triggering another magnetic pulse to quench the gap. To sum it up a sync 
> trigger and a event(first notch) trigger for a single electro-magnet.
>Feasible, with a lot of work or just random ramblings.
>Cheers,
>John


Just thought of something . . .  First, I was (and I'm sure many others) 
are thinking the same type of thing - a reverse triggered gap kind of.
Trigger exactly when you want the quench to take place.  Problem is, if you 
try to quench on a zero current crossing with a magnet, you won't get 
anywhere until the current reaches some higher value.  As someone already 
pointed out, a magnetic quenched gap works by deflecting the arc by 
"pushing on the moving electrons - F = qVxB.  Problem is, for there to be 
an velocity, there has to be current flow - so at a zero current crossing, 
there is no force on the plasma channel.  Honestly, I don't see what the 
advantage is (performance-wise) of a magnetic quenched gap vs. air blown.
Seems like the air blown gap would help everything - disperse ions, make 
the arc path longer to help quenching, and cool the terminals.

Sean Taylor
Urbana, IL