Re: magnets for gap quenching?

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

Original poster: "Jason Johnson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <hvjjohnson13-at-hotmail-dot-com>

I've used some rare earth magnets around my gap. They worked great! The ones
I used were kidney shaped NIB (neodymium iron boron, I think) ones out of an
old hard drive. They could lift 80 lbs of iron a piece. I used two on my gap
and they were spaced around half an inch away from my brass electrodes (on
my airblast gap, with no airblast). I had two peices of lexan on the 1/2"
square Al sotck that holds my electrodes, holding the magnets apart. They
weren't glued or anything the magnets just held them there. The best way to
get the gap to quench is to arrange the magnets so that the poles on one end
are alligned w/ the gap. The only problem I had with the setup was that the
arc was being pulled against the lexan and started melting it. This is a bad
thing if you let the arc pull out and touch your magnets, they lose the
magnetic properties at around 300C, and they burn like magneisum once
ignited (if you've never seen magnesium burn, it is white hot, can reach
several 1000s of degrees celcius, and if in quantity, once started doesn't
stop until its all burned), and they produce some exceedingly nasty fumes
while burning. In my experience they quench great, and they made my gap
sounded like an automatic gun with a very high rate of fire. This was with
my 4800 volt dual MOT supply, a 110nf tank cap and about 16uH of primary
coil. If you want to find large NIB magnets check out ebay or if you have
any old LARGE (in size that is, not capacity, 5.25" high performance hard
drives under 100mb usually) hard drives there should be a pair in there.

Jason Johnson

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, April 16, 2001 10:02 AM
Subject: Re: magnets for gap quenching?


> Original poster: "Jason Petrou by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <jasonp-at-btinternet-dot-com>
>
> Yes! Magnets can be used to quench SG's. This same method is used in
> industrial high current relays to quench the arcing across contacts during
> operation is DC circuits. The magnetic field, generated by a coil in
series
> with the high current circuit, is set at right angles to the direction of
> the arc across the relay (or SG) contacts. This effectively 'blows' the
> ionised air off the contacts as soon as it forms, leaving you with a very
> shot burn time of the arc in your SG - perfect! I have yet to see however
a
> magnetic quenching system that works better than an RSG though!!!
>     Keep in mind that there are no 'magnets' as such for magnetic
> quenching - it is more of a solenoid. I tried it once and first time i
> melted the solenoid and nearly blew my NST. I tried it again with some
> thicker wire (awg22 I think) and it worked, but RSG's still work better.
If
> anyone manages to get an magnetic system working though, email me cos i
want
> to ditch those old cpu fans...
>
> Jason
>
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Sunday, April 15, 2001 11:25 PM
> Subject: magnets for gap quenching?
>
>
> > Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <RQBauzon-at-aol-dot-com>
> >
> > is it true that magnets can be usd for quenching spark gaps? i do
believe
> > that they distort the feild of ionized air in the gap therefore
> distributing
> > the hot ions and quenching the gap without a blast of air or the use of
a
> fan
> >
> >
> >
> >
>
>
>
>