On Jun 23, 2007, at 10:30 PM, William Beaty wrote:
On Tue, 12 Jun 2007 10:36:57 +0200, "Michel Jullian"
<[EMAIL PROTECTED]> wrote:
About the low current phenomenon, it occurs to me that a
sufficiently
low current ion stream, where the ions would form a clearly discrete
dotted line rather than a continuous-looking stream, would not
expand
sideways by self repulsion as we have been assuming all along.
Each ion
would just follow the previous one at comfortable distance, only
sigzaging slightly along the line of maximum field while it collides
with neutrals every micron or so. Could this reconcile the ion wind
theory with your observations?
Yes. I later found that the emission of a linear chain of charged
particles is called "electrospray." If a charged droplet is upon the
surface of a metal electrode, then at sufficient high fields the
droplet
is distorted into a cone, a "Taylor cone." And when the tip of the
cone
becomes sharp, then it emits a charged droplet. The droplet
shields the
portion of the cone below it, so the sharp tip recoils, but only
until the
droplet is pushed away. Then the field grows strong again and the
sharp
tip spits out another charged droplet in an evenly-spaced sequence.
Damp hair fibers definitely create better "threads" than very dry hair
fibers. I originally assumed that this was due to conductivity
of wet
hair. But now I suspect that microscopic water droplets are being
emitted.
How quickly memory fades:
"When I used a soda straw and blew upon a thread with all my might,
the dot in the mist only moved a little. The 5mm dot was changed to a
10mm x 30mm blotch. INCREDIBLY BIZARRE! The air blast either causes
the thread to spread out into a narrow fan, or it causes it to
vibrate at high speed so that the thread tip traces out an oblong
blotch in the mist. These threads are robust! Not at all like smoke,
they are more like carbon-fiber spiderwebs under high linear
tension... I've seen two threads with 5mm spacing between them, yet
they were 15cm long. If they were highly charged, they would repel
apart. If they are ions, there must be both polarities of ions
involved, so that the charge of the thread is very weak in relation
to the charge on the metal tray... I've seen pairs of threads come
from a fingernail top, extend down about 10cm and apparantly follow
the field lines, all the while maintaining a distance from each other
of about 1cm! They don't seem to repel each other much. "
The above quote from:
http://amasci.com/weird/unusual/airexp.html
On the other hand, when a sharp liquid cone starts emitting a charged
fiber, that's called "electrospinning." Viscous liquids applied to
charged metal electrodes apparently will send out "spider webs"
spontaneously.
It still seems to me only experiment can tell which. I still think
you should be able to tell the difference by the signals.
-----------------
| |
V Emitter |
P
_ Plate |
| T1
| |
| |
-o-R1---G---R2-o-
| | |
o o o
V1 G V2
Fig. 1 - Circuit diagram for drop/thread detection
Fig.1 is another sample circuit for doing so. P is a smooth DC power
supply floating above R2 and T1 (one technical difficulty with this
approach). The plate current goes through R1 to ground G. This gives
two current proportional voltages V1 and V2 close to ground and thus
easily amplified (a major advantage). If the current is carried by
charged droplets then the current signals will be wildly different in
timing. If the current is carried by conductive filament then the
signals should be comparatively flat. It may be possible, depending
on needle choice and humidity, and/or possibly CO2 concentration, to
generate either mode. If the needle emitter is in conductive
filament mode, then it should be possible to instantly send a HF
signal injected by transformer T1, and which is not received at the
same magnitude when there is no filament. Further, if the plate is
bifurcated, (and another current sense resistor R3 added) and the
emitter moved from above one plate to above the other, then a droplet
beam (or dry air dry needle signal) should transition current from R1
to R3 more gradually and smoothly than a conductive filament (or set
of multiple simultaneous filaments, which would give a step function).
Regards,
Horace Heffner
