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Re: [TCML] HIGH Q number crunching WIP update



Terry,

Its exactly my point of a high Q system, its all down to fast energy transfer. I see classic designs as just "sluggish" and just will never be able to make it into a high Q system. Also as frequency rises, the need of a large top capacitance may greatly be reduced. From a conservation of energy point of view, even a 12" toroid will seriously kill the voltage gain next to nothing... Though we all use them as they work better... though IMHO the larger toroids are just moving the point in the spark gap's cycle by fine tuning the frequency by using a larger/smaller toroid kinda thing. Again its down to poor spark gap design. I personally do not like the idea of 200nF tank caps running on 8KV with large inductance secondarys and large toroids.. I choose my 20KV voltage very carefully for my high Q system in order to use just 80 turn's on the secondary, in fact 80turns is actually double the number of turns I wanted to use, though always a limiting factor somewhere so constantly have to compromise the design.. 80 turns is the borderline, anything anymore and the design will just not work. Much the same as the toroid also, I have not accounted the toroid into the mix yet, though if you notice the secondary is slightly higher in frequency than it should, simply because the toroid is missing. Really I aim to do away with the toroid all together, I just want something there to stop the last few turns of the coils from sparking, really just needs a corona ring in place of the toroid.. If I go from 1 10pf to 20pf top load, it just halved my output voltage gain. I also want to trap the energy into voltage and not current in the tank circuit. This should help the spark gap quench faster and higher voltages should have lower resistive losses across all the wiring than pumping larger currents though them.

Anyway, Each step of the design has had a lot of thought and design, I am not 100% happy with everything, though of course the limitations of parts and cost is always the largest killer in any design ;-)

Chris





----- Original Message ----- From: "piranha" <piranha@xxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Tuesday, April 15, 2008 2:27 AM
Subject: Re: [TCML] HIGH Q number crunching WIP update


Hi,

The Scan Tesla project ran into all this right quick! It does all this in real time uS to uS... You need to get some serious high voltage on the terminal to get the game started just to begin. Then high 'Q' is important in the first stage for the break out voltage. But then you need some serous and fast feeding 'energy' to make, and then feed, the spark over time to lengthen it out to the max. That is where that BIG terminal comes into play and it's ability to supply fast energy to growing spark ;-)

Terry


Chris Swinson wrote:
The issue of KV output is a comparison between 2 types of coils, that was the baseline figures used to setup both coils. How it will work out to actual spark lengths is another matter where only build it and see will really answer that one.

I know all about the capacitance and toroid problems, already documents pages of data upon all that already posted to the list some time ago. Its a whole epic in itself unfortunately.

MadK I think had a Q of 2000 , JAVATC was 1000 or so I think, I don't know how to "measure Q", Though I know the coil gain is at least 1,000. based on 1V input and somewhere around 1,000 to 2,000V output. Which really does not make much sense but that's the whole idea of trying something new.

coil Q does not matter too much in classic coils as so many other factors swamp and Q factor tests. Like one cannot just decide to place a high Q coil as a direct swap for a low Q coil and expect it to work, I think in general it is known that high Q coils probably work worse, but you have to re-design the entire setup from bottom up to make use of high Q coils. Probably sticking my neck out on the line, but its what has been concluded over the past year or so of number crunching and design testing.

When I tested coil gain on 1V, that wasn't even a in tune system, single shot pulse testing, at resonance the figures should be a lot higher. Its also on the basis that 100V input will give at least 1,000 times that ( 1000x100 = 100,000V) So worst case isn't to bad, it will output "something" which is all I am really interested in at the moment.

Cheers,
Chris



----- Original Message ----- From: "Lau, Gary" <Gary.Lau@xxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Monday, April 14, 2008 5:25 PM
Subject: RE: [TCML] HIGH Q number crunching WIP update


It might be prudent to think about just what coil parameter really correlates with "performance". You suggest that the output KV would indicate relative performance.

I would point out that an easy way to boost the peak secondary voltage is to minimize secondary capacitance. By conservation of energy, the same input bang translated to a smaller topload capacitance would yield a correspondingly higher voltage. But the experience of anyone who has experimented with different topload sizes is that larger toploads almost always result in longer sparks. Granted, the resulting topload voltage is no doubt lower with the bigger toploads, but it points out that what constitutes "performance" may not be topload voltage.

It's also not clear to me that secondary Q is terribly important to performance, by any measure, in a disruptive coil. For CW coils, it does matter though.

I'm not familiar with how JavaTC arrives at things. Did JavaTC give expected Q's of your competing coils? Have calculated values been validated with actual measurements?

Gray Lau
MA, USA



-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
Behalf Of Chris Swinson
Sent: Monday, April 14, 2008 10:31 AM
To: Tesla Coil Mailing List
Subject: [TCML] HIGH Q number crunching WIP update


Hi all,

2 PDF files, the first one shows the demo coil in JAVATC but reduced to 0.6J
( running on 8KV )

The second pdf shows my current construction for my high Q system. OK I
missed out a fair few bits, but according to the results the high Q 80turn
coil can easily do just as well as the 895 turn demo coil.

For those who want to skip to the point, both designs appear to output the
same KV ( well they do math wise). Though I hope my high Q design will
actually perform a lot better than a conventional coil... easier said than
done, but every step of the way is a calculation nightmare, but getting
there!!

http://www.future-technologies.co.uk/temp/javatc.pdf

http://www.future-technologies.co.uk/temp/javatcQ.pdf

http://www.future-technologies.co.uk/IMPULSE/20kvq/ ( a little more info )

There are 2 designs using the same secondary, one is a high Q LV design
(100V solid state design) and the listed 20KV design. There is actually a lot of work and data to crunch and of course is taking its time to build :-(

Currently building a 20KV pulse cap out of tin foil and food tubs, been 10
years since I built one, the good old days ;-)

I might also add apologies for the poor pdf print out, and poor WIP hack of
JAVATC too :)

Chris


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