[Prev][Next][Index][Thread]
Re: Tesla Coil toroid Size
In a message dated 98-09-13 09:16:06 EDT, you write:
<< John F -
> I was happy to hear that someone had performed the input watts test.
> There are several possibilities why you did not find an increase in the
> input watts when you increased the toroid size. One reason could be that if
> you were not using controlled sparks the varying streamers would make it
> difficult if not impossible to correlate the streamer energy with the input
> energy (watt seconds).
John C, all,
The difference in the spark length with the larger size and larger ROC
toroid was so dramatic and obvious, that is not possible to make a
mistake. With a small toroid the sparks were 29" max in one test,
but 40"+ with the larger toroid. Here i am talking about max spark
lengths, so it is true the streamer energy is probably not correlated
to input energy, because steamer energy is stored in the streamer
channels, from bang to bang in unpredictable ways. I don't have a
problem with this, and don't feel a need to use controlled sparks.
> When you say that the larger toroid holds more energy for fewer streamers
> do you mean that the toroid is storing energy from more than one bang?
No, the toroid energy storage is very short term, and can't carry over to
other
bangs. It can only store energy during a portion of one RF cycle. By fewer
streamers, I mean fewer *simultaneous* streamers. I should have made that
clearer. BTW, I don't think I've seen much on the list about this last point,
(about the fewer streamers, not the storage), other than my own postings.
I don't know if others consider it so natural
and expected, as to be not worth mentioning, or if they actually disagree.
I wonder what portion of the increase in spark length resulting from a
larger toroid can be attributed to this mechanism? Maybe some of this
was discussed before i joined the list?
>As
> you know I mentioned this in a past post and there were so many members
> that felt this was impossible they almost convinced me that I was wrong.
> However, it may be that energy is stored in the electric field surrounding
> the coil but not in the toroid.
Only *almost* convinced? I thought you were convinced on that point :)
Yes, the energy is stored externally to the toroid and coils between bangs,
in the fields, or streamer heat or whatever. There's been plenty of
discussion on this.
> Even with controlled sparks the increase in input watts when the toroid
> is increased may be hard to detect if the input is varying. A small
> increase in the spark length does not require much energy. What were your
> input and output conditions when you made your tests?
I didn't try the controlled sparks method, my input power tends to be very
steady due to the use of the sync gap. If there is sometimes a variation
in the power meter needle, it doesn't seem to necessarily correspond to
the spark length at that instant.
I don't see how a large toroid could affect the power input. To have an
effect, it would have to affect the max voltage charge on the cap before
gap firing, (assuming quenching stays the same). I would think that
any effect that the toroid would have on the charging of the cap would be
orders of magnitudes too small to explain the longer sparks from the
larger toroids.
John Freau
> John Couture >>