stun guns / High Voltage / Forums

Forums

4hv.org :: Forums :: High Voltage

« Previous topic | Next topic »

stun guns

previous 1 2

Move Thread

LAN_403

quicksilver

Wed Feb 23 2011, 05:17PM

Registered Member #1408 Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679

Arcstarter wrote ...

It is just a stepup transformer and inverter, which charges a cap which is discharged through another stepup transformer. It isn't constant current like a transformer, it is a pulse transformer like in a camera. You can compare it to a camera, the few kv trigger voltage is from a cap charged by a stepup transformer, which discharges into a pulse transformer.

It's interesting that you should say that. I was pulling caps from a large amount of disposable cameras and got a shock from one. It hurt and in caused a muscle spasm in my leg (where it had made contact). It certainly would have been more than a bit annoying had it been stepped up. Unquestionably something of this nature could dissuade someone. However in that example obviously the voltage was obviously >200v and current possibly above 2 ma.
It was quite annoying.

The patents that I remember had a very similar design. One very interesting feature was the final transformer, which in two examples was a ferrite core "bar" with it's primary inside the secondary (often sealed). Having seen this "final coil" design twice, it seems this is a method of obtaining the visual arc & diminishing the current further.
I am not sure how they work the "number magic" but I believe you are right on the money as to how the object functions as this could be reproduced as a inverter design using very few, very inexpensive parts.

haxor5354

Thu Feb 24 2011, 02:55AM

Registered Member #2063 Joined: Sat Apr 04 2009, 03:16PM
Location: Toronto
Posts: 352

Grenadier wrote ...

haxor5354 wrote ...

Its the volts that jolts but the mills that kills. its prabably a tiny flyback that operates at a low frequency so that the skin effect is eliminated and the victim can feel the shock

The skin effect doesn't come into play until about 4MHz. (at least on flesh)

im pretty sure 4MHz of HV arc would cause serious RF burns

klugesmith

Thu Feb 24 2011, 04:00AM

Registered Member #2099 Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716

Microwatt wrote ...
... I have seen them marketed to make as high at 2 million volts.

Yeah, the marketing is pretty crazy.
I'm reminded of this article about Taser sales parties for women:

Bored Chemist

Thu Feb 24 2011, 08:55PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

Why do people keep saying that sort of thing?
Ohms law says you can't have one without the other.
I am- to some poor approximation, a 10kK resistor. 100 volts will give about 1mA.
( I'm assuming the contact is poor, but the point is the same anyway.)
You can't have the "mills" without the Volts.

For fairly short pulses, it's the energy dissipated that kills, unless you are unlucky and the pulse stops your heart.

Patrick

Thu Feb 24 2011, 09:16PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Bored Chemist wrote ...

I do agree with others that, 4-6MHz is needed before the skin effect matters in us humans. (e^x, remember precalculus?)

There are multiple modes of death, much less than milliamps HAVE killed people, and having several amps connducted trough others have left them injured but alive, volts are a factor but :

In general:
--Low voltage can kill, or not kill.
--High voltage can kill, or not kill.

--Low current can kill, or not kill.
--High current can kill,or not kill.

--The impedance of the human body varies from second to second and from location to location, we are not homogenous.
--Power/energy maybe irrellivant in contributing to death, aside for exploding limbs off the body, like a land mine
(and IR^2 peak heating).

People seem real facinated with that magic 1 amp number to stop the human heart, crap... all crap. much less than 1 amp can cause death (especially during the T-wave phase of the heart beat).

Supposedly electrical devices here in the US must put out less that 75nA (if I remember right) to comply with federal law for Van De Graf type devices in schools.

A better way to look at the relative safety or lethality is with probability... 99.5% likely-to-be lethal, or 99.5% less-than likely to be lethal are the two common ones governments, and corporations use. ( there are many differnt ways these numbers are calculated ).

But my personal standard is to just not get shocked, thus I dont worry about this numerology crap.

previous 1 2

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob