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

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dmitry (father dest)" <dest@xxxxxxxxxxx>

Hello Boris, Malcolm.

>  > "less than 5 usecs. rise time" - oh yeah? and what
>  > secondary inductance do
>  > we need for this? did they ever try to calculate?
>  > impossible! LOL :-)))

> Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

> Maybe not. Consider that at the point of spark initiation the
> terminal is at some high voltage - for a brief interval it could be
> considered to be HVDC. Spark propagation is a pretty rapid event by
> comparison with the resonant frequency. I think you can discount the
> impedance of the secondary when considering such an event.

> Original poster: boris petkovic <petkovic7@xxxxxxxxx>

> Good point.
> High current spikes in short time intervals due to
> parasitic L-C elements (top turns of the secondary
> ,toroid ,discharge path etc) are attainable in such
> experiment.

it depends on what you mean under "rise time" - if examine starting
process of toroid discharge into hv cap - yes, there could be even
hundreds of ns, but why do this? at this only small amount of energy
is transfered, it can`t provide such bright and thick discharge like
on picture. so i disagree with Malcolm, but agree with Boris:

> But I also suspect that most of the energy is released
> in low frequency mode at frequency determined by C
> value of the storage capacitor and L (DC inductance)
> of the secondary.
> It would be interesting to make small scale experiment
> and appropriate msms to see what would be going on...
> To use say 7 joules instead of 7 kJ.

i`ve got a friend (he`s registered at 4hv.org
http://forum.4hv.org/index.php?board=;action=viewprofile;user=Alexey
maybe even he`s subscribed at this list - we did communcate long time
ago last time) - i showed him this photo and he tried to make
something similar. i remember he connected a charged cap in series
with secondary - in ground path. voltage on cap was around several kv,
energy ~500j. he said the bang was quiet and the arc was glowing
rather long period of time, but it was not so bright. as far as i know
he doesn`t have any equipment to measure anything.

b.t.w. - 75j is not enough for 10ka even if in the discharge path
there`re no inductances at all, coz inductance of 6' of air is about
1.8 uH :-)

-----
I have run coils up to 20KW in residential neighborhoods.  I have
received death threats and have had the police, fire, and department of
water and power all show up at the same time. Screw 'em all.  Keep firin'.
(c) Mark Barton  29-09-95