Re: [TCML] High Power Static Gaps

[jhowson4@xxxxxxxxxxx]

I am not sure but I think that i heard something a while ago about a pressureized sparkgap.  They pressurized it with nitrogen which oxided and they had a heating problem.  in the end they just put a squirlecage on the enclosure to mave some air.

-------------- Original message -------------- 
From: bartb <bartb@xxxxxxxxxxxxxxxx> 

> But consider this, high velocity air in a non-pressurized chamber across 
> a gap versus high velocity air within a chamber across the same gap 
> causing pressurization. How do these two gaps differ? It's the pressure. 
> And that pressure will increase the breakdown voltage to arc the gap. 
> With a gap set equally between these two gap types, the pressurized gap 
> will perform better since it will require a higher voltage to arc the 
> gap, summing to a higher energy bang. I think when all things are set 
> "equal" (breakdown and air velocity), there may not be much of a 
> difference. I don't see the mechanism for it. I'm not saying there is no 
> difference, simply that I fail to see the what it is. 
> 
> Take care, 
> Bart 
> 
> Quarkster wrote: 
> > Bart - 
> > 
> > I'm not sure that I agree that the performance "will be the same". 
> > 
> > Certainly, you can increase the width of the non-pressurized gap so the 
> breakdown voltage is the same as a pressurized gap. However, one of the largest 
> benefits of of a correctly-designed "pressurized" gap is the extremely high air 
> velocity through the gap. Quenching should be measurably better than a simple 
> ventilated TCBOR gap, or even a vacuum gap where the maximum pressure 
> differential across the gap can never exceed 14.7 PSI. However, I don't have 
> comparative data at this point ..... 
> > 
> > Regards, 
> > Herr Zapp 
> > 
> > --- On Sun, 9/7/08, bartb wrote: 
> > 
> > From: bartb 
> > Subject: Re: [TCML] High Power Static Gaps 
> > To: "Tesla Coil Mailing List" 
> > Date: Sunday, September 7, 2008, 4:46 PM 
> > 
> > The static gap DC Cox has been discussing this last year in various 
> > postings is just this. It's a simple pressure gap. Nothing special other 
> > than the pressure is changed via forced air. A pressure gap changes the 
> > air pressure. This increases the breakdown voltage for a given distance 
> > and electrode geometry. 
> > 
> > With "all things equal", I don't realize longer sparks. All 
> > things are 
> > not equal. To equalize the gaps (pressure versus not), increase the gap 
> > distance on the non-pressurized gap to equal the breakdown of the 
> > pressurized gap. At that point, they will perform the same (and harder 
> > on transformers because of the higher breakdown voltage). 
> > 
> > Regards, 
> > Bart 
> > 
> > futuret@xxxxxxx wrote: 
> > 
> >> Another (at least theoretical) advantage of using pressure for 
> >> the gap is that the gap spark length is shorter in higher pressure air 
> >> than in lower pressure air for a given voltage. Short sparks have 
> >> lower losses so a stronger spark output streamer length should 
> >> result. I'm not sure how much difference it makes in the 
> >> real world. I think Gary Lau used this approach when he 
> >> switched from his vacuum gap to his vortex gap. It's interesting 
> >> to note that whereas Gary obtained around 63" sparks from his 
> >> vacuum and vortex static gaps, he obtained around 80" or 90" 
> >> sparks using a sync rotary spark gap, using the same NST power supply 
> >> transformer. 
> >> 
> >> I don't think all that much work and research has been done in 
> >> this area (high powered air blast quenching for Tesla coils), so it's 
> >> worth 
> >> more experimentation. 
> >> 
> >> An useful approach might be to add an electronic trigger electrode 
> >> for stable 120 bps operation. This adds complexity, but not of 
> >> the mechanical machining type. 
> >> 
> >> John 
> >> ---------- 
> >> 
> >> 
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