Re: Tesla Coils (fwd)
Replying to your post....
> As regards the ion cloud, freq shifting, etc, I only want to know one
> thing. What is the "critical minimum" break rate. We can see
> obviously that a short braat produces short sparks, and obviously, the
> ion path needs to hang out across interrupter breaks. How many pulses
> are needed to achieve full length discharge? What is the SLOWEST break
> rate I can use and still have this ion path hang out? I ask this
> because it becomes obvious (sorry about all the obviousness) that for
> maximum DISPLAY, we should hit the coil the least number of times per
> second possible with the biggest wallup possible. And you can get
> bigger wallups if you put more time between them.
A few operating observations and rambles:
Richard Hull talks about ion cloud hangout in the 100's of mS
range (I guess with no wind), so there might be outdoor operating
limits factored in there. When I used to run a Van de Graaf, there
was experiment I did that showed how long ionization could last
(could probably do it single shot with the coil as well). Holding
the contact end of a clear light bulb (argon), a discharge to the
glass left a blue swirling ball of ions which took half a second
or so to fade out. But that was all very contained.
(1) I have had good results at 100BPS equiv. (NZ mains - 50Hz) with
large bangs and large caps.
(2) Gap fires are increasingly difficult to put out as C gets smaller
and as BPS goes up, quenching and prevention of transformer
losses becomes impossible.
(3) It has become clear that the spark gap is behaving like a zener
(4) The procedure I'm concentrating on now is to get the longest pos-
sible spark from a given secondary in single shot mode for a
given primary voltage (increase Cp, decrease Lp until max. is
obtained) then adjust BPS for best. To improve on this I think
would take more Vp or a lower frequency secondary (more Cs, Ls
I should have some experimental results to report some time in the