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On 12/29/14 12:50 PM, David Rieben wrote:
Hi all,
I came across something today and I hope the moderators will allow a
bit of latitude here and let me get some feedback from the
genius-level collective think tank of this illustrious list. ;-) It
is my understanding that a typical stun gun uses a small solid state
pulsed circuit to produce the high voltage discharges - similar to an
OLTC circuit (or is it more akin to a Marx bank?). One thing that I
can't help but notice though is how the voltage claims of commercial
stun gun manufacturers has reached ludicrous levels and was wondering
if anyone else has noticed this trend? 50 kV, 100 kV, 200 kV, 500 kV,
1 MV, 5MV, and now - 49 MV? Just how much voltage does it take to
"stun" someone, anyway? :-D
I suspect it's more a "joules" thing than a voltage thing. And given
that the two electrodes are a few cm/inch apart, what you're really
looking at is figuring out what the resistive impedance is, to put
however many joules you need.
BUT... getting to the bizarre voltage claims.
.com/itm/Silver-Scorpion-X-High-Voltage-Stun-Gun-LED-Light-Rechargeable-USB-Cable-/121525955612?pt=LH_DefaultDomain_0&hash=item1c4b82ec1c
I'm thinking "49 million volts" should be in the same range as the
potentials seen with real lightning :-) I do realize that the nature
of the voltage source as well as radius of curvature of the
electrodes, along with atmospheric conditions can cause some widely
varying spark discharge lengths vs. a given potential, but the stun
gun manufacturer voltage claims have gotten to the point that they
insult the intelligence! Obviously, there is little or no
verification or oversight to the outrageous voltage claims of these
devices. Thoughts?
Anyone can claim anything on eBay, etc. and there's probably not much
you could do about it. Buy one of those 49 MV units and then ask for a
refund because you measured it at a few kV (at most).
Go after them for consumer fraud?
I seem to recall some time ago that someone on this list actually
measured the voltage (but I can't find it in the archives, so maybe not).
I've seen units with two "prongs" and a spark jump about 2cm between the
prongs, which were fairly sharp, so I'm going to guess voltages in the
10kV range but that's "open circuit" not "under load", which is probably
in the 1-10 kOhm range.
Something like a automotive ignition coil will easily do this, but the
100 mJ energy in the ignition coil isn't going to "stun" you (as anyone
who has been zapped working a car can tell you).
" For example, a TASER CEW has about a tenth of the peak current of a
static shock"
I rummaged around on the taser site looking for actual waveforms and
numbers, but couldn't find anything, but 5kV sounds plausible and not
too hard to manufacture.
"In one implementation, a handheld launch device includes 8 AA size
(1.5 volt nominal) batteries, a large capacity capacitor, and
transformers to generate a 26-watt EMD output in a tethered projectile."
Looks like total energies of 1-10 Joule (compare to a 300-450 Watt NST
powered tesla coil which will have a bang energy of several Joules/bang
at 100-120 Hz.)
That 26 watts, then is consistent with what the wikipedia article says.
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