________________________________
Von: ecat builder <[email protected]>
An: [email protected]
Gesendet: 20:25 Mittwoch, 30.Mai 2012
Betreff: Re: [Vo]:Spark plugs... thoughts and how-to?
Brad,
>>>>>>>>>>>>>>>>>>>>>
A quick followup on spark plugs.. I think I found what I was looking for.. A
small, cheap, and simple spark gap igniter that takes 5V and produces 1/2"
sparks. Less than $20 shipped.
http://www.sparkfun.com/products/11218
Skip to 10:45 on the video to see it working.
>>>>>>>>>>>>>>>>>>>>>
Some basic issues to consider:
a) to me it does not seem to make very much sense to just produce a spark
between two pointlike electrodes. It probably quickly melts or degenerates the
target (Nanopowder, whatever).
You have to distribute the ionization to an area.
b) standard ignition-coil sparking is indifferent to polarity.
See eg here:
http://www.worldphaco.net/uploads/ELECTRONIC_IGNITION_FOR_TR_CARS.pdf
Fig 9.
This paper also has some very comprehensive basic circuit and coil-model. (Fig
3,4)
so:
b1) consider to rectify the secondary voltage, as I tried to sketch in one of
my pdf's earlier on. If You do not do that, H+ direction mostly simply
oscillates around the point of ionization up and down, and annihilates itself.
Typical reversal times are some 130usec, which translates to small H+ travel
distances. The effect is, that H+ rarely reaches the target.
Maybe someone here can compute/reasonably estimate the half-life of travel
distance of H+ under 10bar or such and E-field in the order of 100V/mm.
I expect it to be some 100um, so the overall effect of reversing a HV-polarity
would be miniscule: <1/1000th compared to when it is properly done.
But maybe I'm off some orders of magnitude.
Properly done, under 1bar condition average Ion lifetime could be >10mm, as one
paper suggests.
Then I would be a factor 100 off. But on the other hand, the precise method of
HV-generation has not been revealed, which is a typical flaw in an otherwise
interesting paper.
Physicists/Chemists rarely have an idea of the intricacies of electronics.
(sorry folks)
This ofcourse could be the difference between life and death, so to say.
Message: Do not go blind, if You can avoid it.
c) it seems essential to me to sensibly control the ignition voltage to
pressure and electrode distance.
c1) in my design-concept the electrode distance is in the order of 3mm, where
some 20kV
should be sufficient even to generate reasonable plasma at 20bar.
d) the charm of using an ignition-based design in such a manner is, that it can
be easily controlled by primary voltage and pulse-frequency.
e) remember: it is NOT the goal to simply produce strong sparks, but ones JUST
strong enough to ionize H2, and NOT melt or in any way degenerate the structure
of the target. This to me would be a strong sign of a faulty setup.
f) a feedback-parameter would be to measure the primary current, which -as I
would expect- rapidly increase if a continuous ion channel develops between
ignition electrode and target (nano-Nickel, whatever).
Maybe this is one of the control-issues our 'heroes' Rossi/DGT encounter, which
can be easily seen if one does not see the problem in producing SOME sparks,
but plasmas, which can be SENSIBLY controlled.
If not, You either do not get an effect at all, or You have an effect too short
to watch, i.e. is killed within msecs.
This all applies to a 'dry process', to be precise, and is not loved by
electrochemists, because they are used to 'wet' processes, involving fluids,
which I, on the other hand, do not like, because they obscure the issue.
Same with Nanospire/LeClair who is basically a mechanical engineer educated in
cavitation and such, and builds a theory upon his experience and misses the
point, that what he is doing is more akin to hot fusion.
Tiny super-explosions in a WET environment!
Btw, I do not see any use for a second spark-plug, except for auxiliary
purposes, which are not relevant for the central task at hand.
It possibly is just convenient to use another (or several) plugs to access the
volume, may this be for diagnostics or whatever.
Guenther
