Re: Lightning Gun To Combat Terrorists - WHERE IS THE RETURN PATH???

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Stork,

At 01:13 PM 9/5/2005, you wrote:

> > Radio waves only need an antenna long enough to create a potential 
> > difference in the presence of electromagnetic waves.  They operate 
> > in free space such as on satellites and space craft.  In a real 
> > way, EM waves tend to bring the ground path along with them ;-)
>
> Oh, I get it, a traveling virtual ground. Is this virtual ground at 
> the same potential as the real ground from where it was launched?

It is an isolated floating ground that could be any potential.  I 
wonder if satellites in open space have any known net charge on 
them?  Maybe Jim Lux would know that?

> Maybe someone could devise an experiment to prove this virtual 
> ground exists and it's potential relative to the real ground 
> potential is the same as it must be, if there is a true return path.

Just put a battery powered AM radio on an insulated string and raise 
it's potential to say 50kV with a DC power supply.  Aside from 
perhaps corona, the radio still works just fine at +50kV.  One could 
probably run a little AM radio on top of a DRSSTC toroid too with no 
problem in the same way this scope was running:

http://hot-streamer.com/temp/DaveTest-82.jpg

http://hot-streamer.com/temp/DaveTest-83.jpg

http://hot-streamer.com/temp/DaveTest-84.jpg

Spark gap coils would probably work too, but the spark gap noise 
would just be greater.  If the radio was tuned to the Fo frequency of 
the coil, you might not be able to pick up much else ;-)


> Otherwise, the weapon shooter would not be concerned if the EM wave 
> took along its own ground path.  No return path back to the shooter 
> is necessary.

Assuming the 1/2 wave length is 6 feet for a big terrorist, the magic 
frequency is 82MHz.  But that frequency would not penetrate vary far 
into the skin.  The microwave weapons work by heating the skin at the 
surface.  Counter measures are trivial...  Just get wet...

Here is a presentation on electrical non-lethal weapons you might 
understand since you are a doctor.  I don't get it myself %:-)

http://www.unh.edu/ntic/NTAR%20talks%20pdf/Cooper.pdf#search='current%20frequency%20pain%20threshold'


> So, on a cold dry December morning Terry is walking in his leather 
> shoes across his carpet.  As his hand reaches for the well insulated 
> front door metal handle a sharp snappy little spark arcs between his 
> index finger and the well insulated metal door knob.  Has the door 
> knob potential changed?

The is a chance of using pure AC "charge" transfer.  Based on the 
free space capacitance, one can transfer AC current much as we do 
with pure streamers. Such as a Tesla coil arcing to a large insulated sphere.

Assuming a terrorist is about 100pF and 100mA is needed to get his attention...

I = V x 2 x pi x F x C    ==>  V x F = 0.1 / (2 x pi x 100e-12) = 160e6

So at 1e5 volts you would only need 1600Hz.  But at 100mA, that is a 
10kW AC power source which would normally be considered far beyond 
the lethal level.  You might as well just shoot them using 
conventional well tested means...

Perhaps pure DC pulsed currents could ride on the RF arc 
channel.  Much like Bill Wysock's multi-kilojoule capacitor discharge 
experiment.  But then you start to need solid return ground paths again...

Seems like a lot of complex details to fiddle with as that rocket 
propelled grenade or AK-47 rounds are coming at you...  I note the 
terrorists videos on TV show them practicing accurately spraying 
machine gun rounds very quickly into a target...  There is a reason 
they train for that...  They known you will get them, "if" you have the time...

Of course, I think the original "lightning gun" discussed here is 
more of a different version of the taser meant to be used in 
relatively controlled low threat circumstances.  But I don't see much 
advantage over the standard taser which has far less to go wrong due 
to having a sure ground return path.


> Where is the return path?

In the pure charge transfer case, it could be purely floating, but 
you would need vastly larger charge reservoirs to hold the opposite 
charges at the source...  But on earth, you could use a grounded 
spike on your shoe.  Just be "real sure" it is grounded!

Cheers,

        Terry



> Stork