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Re: Tesla Coils (fwd)

Hi Mark,
         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 
    diode. 
(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
    or both)

I should have some experimental results to report some time in the 
next week.

Regards,
Malcolm