Re: Solid state gaps - what happened? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 6 Jun 2007 19:19:46 -0500
From: D.C. Cox <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Solid state gaps - what happened? (fwd)



We are in the process of building a dual MOT with series secs using Mark 
Dunn's SISG boards.  Sec is 14 inch dia. and it features a 40 x 12 inch mesh 
toroid on top.

Look foward to initial testing soon.

Dr. Resonance


>
> Gary,
>
> --- Tesla list <tesla@xxxxxxxxxx> wrote:
>
>>
>> ---------- Forwarded message ----------
>> Date: Wed, 6 Jun 2007 15:29:06 -0400
>> From: "Lau, Gary" <Gary.Lau@xxxxxx>
>> To: Tesla list <tesla@xxxxxxxxxx>
>> Subject: Solid state gaps - what happened?
>>
>> Just about a year ago Terry Fritz came up with a
>> very clever, modular
>> IGBT-based replacement to the static spark gap.
>> While the price tag was
>> steep and far more complex than conventional gaps,
>> the reported
>> efficiency gains seemed hard to ignore.
>
> Well, I built one (SISG) last week, using a different
> IGBT which lacked an internal anti-parallel body
> diode.  I had a stock of MUR860's left over from my
> SSTC experiments and I added these in place of the
> IGBT diodes.  With two segments and a single MOT I am
> getting 2 inches of roaring power arc at 25v on the
> variac...however, my tank cap is way under rated, as
> it is a single CD 942 150nf cap.
>
> I'm also in the process of designing my first DRSSTC,
> but I loved the elegant simplicity of the SISG, and
> after reading Terry's SISG.pdf a few times, I couldn't
> resist the urge to build a prototype.  My IGBT's are
> Fairchild G27N120BN and were just some I had sitting
> in a box from an impulsive ebay purchase made when I
> did not know that a "D" in the part number indicated
> the body diode was present.
>
>> It wasn't clear to me if the
>> SISG was truly a drop-in replacement to conventional
>> gaps, but it seemed
>> to hold great promise, considering the
>> ever-decreasing cost of silicon.
>
> It "can" be a drop-in replacement to conventional
> gaps, but it also goes places where conventional gaps
> can scarecely tread...such as switching the relatively
> low voltage of a single MOT.
>
> Whether it fulfills Terry's dreams from the original
> posts or not isn't really that relevant in my opinion.
> It is so cool and simple it doesn't really matter!
> It has revitalized my (once dead) interest in
> disruptive coils.  Once you twiddle the controls of a
> growling SSTC and can change the color, thickness, and
> sounds of sparks...SGTC's tend to pale in comparison.
> The intrigue of solid state coils such as the DRSSTC,
> SSTC, DF-DRSSTC, and OLTC is compelling.  It is really
> not very complex either...it's just trendy to say
> that, plus I think it helps a lot of people justify
> the fact that they are sitting around saying that.
> Just look at the DRSSTC wiki at 4hv.
>
>> I recall there was ongoing work on triggered
>> versions too.  I don't
>> recall if quenching (or lack there-of) was thought
>> to be an issue.
>
> It didn't stop Mark from getting 40+ inch sparks,
> Terry 30+, or Finn Hammer from getting 60 with his
> brick switched BRISG.
>
>> Now a year later, not a word to be heard on the
>> topic.
>
> In some places people are talking about it.
>
>> I'm just
>> wondering - was the cost just too high and the
>> practical efficiency gain
>> didn't merit the cost, or if one is going the
>> spendy/complex solid state
>> route, DRSSTC's do better, or did we just forget
>> about it without Terry
>> to tout it?
>
> The IGBT cost is high right now, but I'm so happy with
> this I'm going to buy them anyway.  As far as "vs
> DRSSTCs go"....some people definately did decide to go
> the drsstc route instead, but I think "real coilers
> should build both".  Ideally we'd like to have as many
> people participating in as many of the topologies as
> possible, just to maximize the chance of a
> breakthrough/discovery.  There is not a thing complex
> about the SISG.  It is easy to understand and
> implement.  Keep away from the primary circuit while
> the power is on.
>
> 4 years ago, I was scared of solid state, I suppose I
> was afraid of failure, and the unknown.  Once I jumped
> in...new year this year, I realized it wasn't any
> harder or more complex than anything else.
>
> I hope I have at least slightly raised the bar of
> optimistic thinking on the TCML.  I have to admit the
> stagnation has kind of bummed me out lately.
>
> Oh...and soon I'll have pics and videos of my SISG
> system for those who are interested.
>
> Cheers,
>
> -Brett
>
>> Regards, Gary Lau
>> MA, USA
>
>
>
>
> 
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