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Re: 20 joules at 100 bps vs 4 joules at 500 bps

Original poster: Steve Conner <steve@xxxxxxxxxxxx>



it`s possible to get big voltage even at small coil, it`s possible to
put a big toroid etc.. i guess nobody of you "at past 10 years" didn`t
try this, nobody was trying to increase electrical strength of the
secondary - instead you just increase its size.

I think pretty much all the bases have been covered on this over the years. It seems that the best ratio of spark length to secondary height is got by sizing the components such that the toroid breaks out just before the secondary flashes over. This is not necessarily the configuration that gives the best ratio of spark length to power input, but we care more about making our coils look spectacular than making them efficient.

*If you put a big toroid on top of a small secondary, the secondary flashes over before you can generate enough voltage to use the toroid to its full potential. The sparks may be big compared to the secondary but they will look puny compared to the toroid. Even if you add fins to the secondary to increase the tracking distance, you will just get excessive hits to ground and the strike rail, rather than long sparks. I tried this a couple of weeks ago (but not using fins) with a 24" x 8" toroid on top of my old 4.5" x 13" spark gap coil, and that was what happened.

*Now for the opposite case- If you put a small toroid on top of a big coil, you will get several short sparks coming out instead of a single long one.


i consider that such "analysis guys" like B & R have so enormous
theoretical and experimental base, that your words:
> We will probably find out lots of cool results in the process that
> will help the analysis guys.
just make me smile

When I say "the analysis guys" I mean the people here on TCML who prefer playing with MathCad to actual coiling. Bazelyan and Raizer are in a different league altogether. But I will say this in our defence-

1) Nobody has really studied Tesla coil discharges since the 1930s. The reason being that there is no way of making money out of them. All of B&R's results (as far as I know) are from Marx generators, DC supplies, and power-frequency transformers. They were presumably working on the design of extra-high-voltage power lines- an application of HV that _does_ have lots of money in it.

Hence, I think it's fair to say that TCML members know as much about our particular kinds of discharges, as any other researchers anywhere. They probably know more about "their" discharges than we do about ours, since they get paid to research it for a day job, but nobody knows how to apply their results to our field.

2) B&R were experimentalists more than analysis guys. They actually went into the lab and created 120 foot long sparks, then thought up some equations to describe them afterwards. That's the same as what we're doing.

3) Their book "Spark Discharge" costs $100+! If you want to shell out for a copy, and try to "adapt" the "currently available facts" contained in it to Tesla coiling, good luck! But I believe Terry bought it, and I haven't seen any 120 foot sparks coming from his back yard yet.


Steve Conner