I agree that heat is the worst problem with any type gap. Heat is the ultimate loss in gaps of "any" type. The type of gap used in the study will absolutely generate a great deal of heat internally and very quickly. There is "no" air center to the electrodes. When coilers build these type of static gaps, they tend to put a muffin fan or similar over the top of it and guess what, usually poor performance. Heat builds inside the tubes and the tube temperature is high and can't be regulated well. Almost always poor performance. I guess if some huge high velocity cfm was pouring over the top, then maybe (power dependent) it might be good, but these flat slab multiple gaps are the absolute worst type I've used and the small tube size is even further limiting.
Single gaps do work good for a short duration. But it doesn't take long until their overheated and performance is nearly null. Surface temperature really should have been part of this study (in hind sight). To me it's an apples and oranges case.
Take care, Bart resonance@xxxxxxxxxxxx wrote:
This certainly makes sense when one considers the immense energy lost in heating each separate multiple gap, and also the UV and light energy losses. Heat is the worst though, and by using less gaps with a nice 500-700 CFM of airflow quenching is usually efficient with low loss of thermal energy in a well designed two electrode gap vs. say a 5-6 electrode gap. Dr. ResonanceIt was after reading a paper published by Terry Fritz that I first came to the opinion that multi-segment gaps have higher losses despite offering better quenching. See http://www.hot-streamer.com/TeslaCoils/MyPapers/sgap/sgap.html. Perhaps I'm reading it wrong, but it looks to me like the peak secondary voltage is significantly higher in the single-gap cases when the coupling is in the region where we typically use it. And independent to that, I'm pretty sure that I've read that spark gaps are similar to zener diodes, in that they exhibit a near-fixed on-voltage independent of gap width. (This is where Bert Hickman usually chimes in...) There is no doubt that multi-gaps exhibit superior quenching over single-gaps, but contrary to what is often repeated on this list, quenching is not the primary determinant of gap performance. Regards, Gary Lau MA, USA-----Original Message----- From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of bartb Sent: Friday, February 22, 2008 9:31 PM To: Tesla Coil Mailing List Subject: Re: [TCML] Spark gap Hi Gary, I'm undecided on the single segment versus multi-segment gap losses. The only possibility of lower losses is "if" the arc resistance is lower in a single segment gap. The voltage drop should be the same for both assuming identical pipes diameters, surface, and total gap spacing. Take care, Bart Lau, Gary wrote:I'm similarly skeptical about a propeller gap's quenching. The onlything that I can see superior quenching-wise is that the air flow over the gap may be better than in a cylinder gap. But if that was all you need for superior quenching, then an air-blast gap should be the best solution of all.I would think that a mult-segment cylinder gap is the best at actualquenching, due to the fact that being divided into multiple small arcs, they would be easier to cool and extinguish. But I also believe that multi-segment gaps exhibit higher losses (each gap represents a fixed voltage drop, and the more gaps in series, the greater the total gap voltage drop, and loss).The benefit of a propeller gap comes about in that it's a rotary gap.If it's a sync gap, it's superior because the bangs can be engineered to be consistent in size and timing, rather than the chaotic mode inherent in static gaps. If it's an async gap, it may be better than a static gap if the power supply is larger than what can be effectively handled with a static gap.Regards, Gary Lau MA, USA_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/teslaDr. Resonance _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla
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