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RE: SS DC TC Data & Victoreen Spark Gap

Hi Barry,
Thanks for all the info.
California in Maryland ! bet that causes some smiles.

re: Victoreen SGCA -(2000?) Spark Gaps:
The 50mA test doesn't pose the very high peak stress encountered in the gap.
It is the high peak current that blasts debris from the gap electrodes.
That's about 1000Apk for my .1uF to 6.7uHy Pri !

Being rated at 100 J, I need to check them out.

I called ALL Electronics, 
they've sold out SCGA's and won't get anymore.

I called Victoreen in Ohio. (now Ohmite div of Inovision)
They have no stock, and don't use distributors !
Their furnaces are down til March.

I learned SGCB's have a longer Quench than the SGCA's,
gap material is Tungsten, some Ni-63, kovar leads,
 in reduced pressure Argon,
voltage is adjusted via gap spacing,
rated for 1 million fires.

General Mgr, Kevin Kreger, 
said they've never tried to trigger them,
delighting at the possibility of a new product line !!

Would you be willing to sell me a few ?  
or perhaps Terry, Dr Res or others on list have some left overs ?

Regards, Dale
-----Original Message-----
From: B2 [mailto:bensonbd-at-erols-dot-com]
Sent: Monday, December 20, 1999 9:37 AM
To: Dale Hall
Subject: Re: Data

Hi Dale,    Replies below:

----- Original Message -----
From: "Dale Hall" <Dale.Hall-at-trw-dot-com>
To: <bensonbd-at-erols-dot-com>
Sent: Monday, December 20, 1999 4:11 AM
Subject: RE: Data

> Hi Barry,
>
> I have Tek TDS420 & 540 photos of my DC TC in operation.
> Power arcs ring up proportional to spark distance
> (3 cycles 200kHz for 20", ~1uS/in)
> and all the energy is quickly sucked out of the system (<1uS)
>
> With no toroid projection/corona, I get about a 7 node ringdown.
> I am aware of the use of magnetic arc suppression control.
> Kilovac uses it in their Cu electrode Bubba series. (kA switching)
> Unfortunately none of the ones I have use a magnet

> Tungsten is nonmagnetic.
> The distance (likely critical to effectiveness) is over 1" to the
gap
>  from the outside glass seal for the ones I have.
> Some have a cup in which the arc occurs and collects W debris.
>
> Perhaps at high enough currents there is self field affect ?
> With my ~600Apk to ~2kApk, tungsten slowly deposits inside the
glass.
> (makes a nice mirror / neutral density optical filter but conducts)
>
> I been wanting to contact Kilovac for tech info regarding
> their use of permanent magnet arc suppression.
> http://www.kilovac-dot-com/
>
> Regarding ignition trigger:

> I suspect a lowly 4kV xenon lamp trigger may do the trick
>
> I should get some of those ALL electronics gaps.

> I am most interested in your results with these "arrester" gaps.
> How have you used them so far ?

I haven't used them so far.  I saw a system in operation built by Mark
Reszartarski (sp?).  He was using a 9 kV, 30 mA neon sign transformer
to charge up a 0.01 uF Maxwell capacitor.  The rep rate was in the
hundreds of Hz.  The surge arrester tubes were warm to the touch after
a long run.  The output seemed quite good.  Similar to an open air
gap.

> Do they have an even more limited life due to electrode splatter ?

Very probably.

> What is the max rep rate they've been subjected to ?

100s of Hz.

> Burned any up ? (max effective rep rate at joules / bang ?)

They are rated at 100 J per pulse
I tried to burn one up by connecting it across a 12 kV, 30 mA (50 mA
rebuilt) and letting it spark (no capacitor) until it got too hot to
touch.  After it cooled down I measured it on the HiPot tester.  Same
breakdown voltage (~2500 V) before as after.  Very rugged.

> What is their contact material ?_____Unknown + Ni 63.
> Try NIB magnets with the poles lined up with electrodes
> and run test to determine if debris can be effectively directed.
>
> Will they hold up to .1uF discharge currents at 7kV 2.5J ?, 14kV 5J
?

> 3 tubes in series should work ok.

> I have been wanting to construct such a substitute gap so that
others
>  could reproduce my results without having to find the Vacuum
relays.
>
> The poorer quench due to air in the gap may limit RQ triggered type
gaps,
> but I haven't tried them as a substitute approach either to
determine
> relative effectiveness.
>
> Manual controlled Single Shots are great for instrumentation,
>  arc length repeatability and control.

I agree.  Anything else is chaos.
>
> Regards,
> Dale
> Redondo Beach, Calif

Regards, Barry
California, Maryland (Chesapeake Bay western shore)