megalomania
June 14th, 2003, 08:16 PM
ILLuSion
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Posts: 6
From:
Registered: NOV 2000
posted 03-08-2001 10:23 PM
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I have been experimenting with making a homemade tazer. Even though mine works partially sometimes, I'm wondering if any of you have made a tazer before? And if so could you illustrate the plans to me?
SATANIC
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Posts: 237
From: australia
Registered: SEP 2000
posted 03-08-2001 10:41 PM
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how did you make it? i've often wanted a tazer, but i think they're illegal here (aus) a home made one would do fine though, they have the advantage of being untraceable
ILLuSion
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From:
Registered: NOV 2000
posted 03-08-2001 10:52 PM
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I just looked at a couple designs of tazers, took a few of my friend's tasers apart and started from scratch from there.
Agent Blak
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Posts: 766
From: Sk. Canada
Registered: SEP 2000
posted 03-08-2001 11:22 PM
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how many volts is it?
does it look like a Peice of junk?
how long idid it take you to build with your reverse engineering techniques?
------------------
A wise man once said:
"...I Am Not Much of a Dancer But,
Just Wait Till The Fucking Begins"
Agent Blak-------OUT!!
CragHack
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Posts: 618
From:
Registered: DEC 2000
posted 03-09-2001 03:39 PM
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you gotta watch out for homeade tazors dude. you hit the victim in the middle of the chest and you could possibly pass a current through the heart. bad news if you only wantesd to knock them down.
------------------
...Æ
ILLuSion
New Member
Posts: 6
From:
Registered: NOV 2000
posted 03-10-2001 03:27 PM
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It is 200,000 volts I think. Yes I know Homemade Tasers are sometimes bad news. I have taken many steps on precaution for them
ASSGREMLIN
New Member
Posts: 16
From: NIL
Registered: MAR 2001
posted 03-12-2001 01:32 AM
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I have a book that shows how to make a tazer, and a load of other crap (lasers, ultrasonic "pain generators," etc.) and i would love to post the plans, but i don't have a scanner For anyone interested the book is called "Build Your Own Laser, Phaser, and Ion Ray Gun." The author basically bought a bunch of the plans from Information Unlimited Inc. ( www.amazing1.com ) and tested them. And although the name sounds cheesy, I've looked at the schematics, and they seem valid.
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 03-12-2001 03:06 PM
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that is a bull shit site and If you buy a laser from them they will send you a blinking led I know people that have orderd from there.
vehemt
Frequent Poster
Posts: 580
From: Canada
Registered: SEP 2000
posted 03-12-2001 05:02 PM
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Amazing1.com isnt a bullshit site, but they do have incredibly high prices.
The author of "Build Your Own Laser, Phaser, and Ion Ray Gun", Robert Ianini(spelling), is the owner of Information Unlimited. He wrote the book nearly 20 years ago(his company existed back then too, the book was somewhat of a plug for the company as a source of parts for certain projects).
Its not bullshit, just really, really, really, old(proven) technology.
Im not saying you should buy anything from Information Unlimited, but what I am saying is that the book is just fine(just borrow it from a library and make some photocopies of the pages you want the plans for). In general information Unlimited is out to get your money though.
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 03-12-2001 05:35 PM
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just dont buy their kits and expect their descriptions to be accurate.
ASSGREMLIN
New Member
Posts: 16
From: NIL
Registered: MAR 2001
posted 03-12-2001 10:58 PM
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Actually, their descriptions *are* acurate (in the book) and although its old, it works.
J
Moderator
Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-13-2001 07:34 AM
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Illusion, do you have any schematics? If not, can you describe the circuit (i/e this block does this etc)? I'm building a stun gun (all info including schematics and current results on my site), I've found the difficult part of the circuit is the HV transformer. I've wound my own, but from descriptions of other circuits I don't think I have a high enough step up ratio.
J
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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
c0deblue
Frequent Poster
Posts: 229
From:
Registered: JAN 2001
posted 03-13-2001 02:37 PM
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J: The HV transformer is pretty easy, but you have to take special precautions to achieve very high voltages without flashover.
Greatest circuit efficiency is obtained with a high frequency primary oscillator driven at 20KHz or higher.
For the output transformer, start with a piece of ferrite rod to use as a core - a piece of the rod from an AM radio antenna works fine (round) or you can use a section of the ferrite core from a TV flyback transformer (usually square). Wrap this with Mylar and wind the coil directly on that. You don't need a "closed" transformer core - a rod-wound solenoid configuration will provide all the coupling you need for this application.
Don't exceed about 2 inches for the coil length as the voltage differential between the ends of adjacent coil layers will be too great. Use corona dope (TV repair supply) on each winding and cover this with .001 Mylar tape. Pay special attention to insulating the ends of each winding layer, as this is the weakest spot electrically.
Overwind the secondary - that is, calculate a turns ratio for 300-400KV - this isn't critical. When completed, test the unit using controlled-gap regulation. The gap distance will limit the voltage output and by slowly increasing the gap you'll quickly find the point at which internal flashover begins. Simply fix the gap regulator distance at a point short of this flashover or insulation breakdown point and you're all set.
Peak to peak output voltage is estimated at the rate of 75KV per inch spark gap (spherical electrodes at 760mm Hg atmosphere and 25C temperature).
Using care in winding and the best insulation materials I've achieved 5 inch blue sparks (almost 400KV) from coils as small as 2.5"L x 1.5"D overall, from a primary circuit powered by two 9V "clip" batteries. Output was limited only by the insulation materials - with vacuum impregnation output voltage of over 500KV could easily be realized.
J
Moderator
Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-13-2001 07:24 PM
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My transformers have so far been limited by the size of the RM10 core kits I'm using. I can wind 1500 turns of 0.125mm ECW on one of these before there is no room for the primary winding. I have experimented using primaries of 10 turns 1mm ECW, and 20 turns of 0.25mm. The 20 turn primary allows the transformer to operate at a higher frequency, although the spark length is nearly the same as the 10 turn primary. Is there a set minimum/ideal number of turns for the primary to get the maximum efficiency?
I might go skip raiding later, there's usually a monitor or two in the university skips ;-) Thanks for the info, I always assumed that a closed core was needed. Is there a possible substitute for the mylar? What about some insulation tape?
Is the order of windings critical? I wind the secondary first, then the primary. This way I can play around with different ratios easilly.
J
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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
c0deblue
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Posts: 229
From:
Registered: JAN 2001
posted 03-13-2001 09:31 PM
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J: Your statement about a 20 turn primary allowing higher frequency operation leads me to suspect you may be using the primary winding of your HV transformer as part of a tuned oscillator circuit. This will work, but output is likely to be limited and current consumption will be fairly high.
The units I've built are 2-transformer circuits utilizing a stand-alone pulse oscillator with its own closed core transformer (also ferrite), and a secondary of between 300-600 Volts. This can be wound using a traditional "E" core, but my best results were obtained with a ferrite toroid. The 300-600V pulse output in turn drives the primary of the ferrite rod HV transformer, capacitively coupled (~0.5uF/600VAC) to limit input current and prevent core saturation. This system also provides a testbed for experimenting with different HV coil designs, since these can simply be interchanged.
Output of the oscillator stage is a 22-25KHz short-duration pulse train at almost the supply voltage (about 16V in this case) driving the toroidal transformer (call this T-1). The T-1 secondary is a (nominal) 450 Volt pulse. With the HV primary as a load in series with the 0.5uF/ 600VAC capacitor, the T-1 output waveshape exhibits a short leading edge but a damped trailing edge (decay curve) due to core reluctance and capacitive effect.
The HV transformer (T-2) is simply a solenoid-wound coil (as previously stated) with the primary wound outside (or adjacent to) the secondary winding. Maximum potential (turns ratio) output can thus be varied by changing the number of primary turns, without in any way affecting the output of T-1.
As to the question of insulation, there's really not much room for compromise when dealing with high voltage. Ordinary PVC electrical tape definitely won't withstand the inter-layer (much less the layer-end) differentials that exist in transformers of such compact design (a problem that doesn't exist with physically large, single-wound Tesla coils). The Mylar sheet used for the core liner ought to be available as drafting film. For the Mylar tape try a specialty supplier such as Jolitape http://www.jolitape.ca/transformer_motor.htm They'd probably be more than willing to supply samples for your "pre-production prototype" or "R&D program".
J
Moderator
Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-14-2001 06:33 AM
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I'm not using a tuned circuit. It is a multivibrator driving a 2N3055 with the output. The primary is connected between the collector and the positive supply rail.
I don't know why the 20 turn primary causes it to operate well at a higher frequency. The 10 turn seems to have an optimum frequency, after which it just gets worse and eventually won't operate.
The nights skip raiding has yielded a flyback out of a colour monitor, so later on I'll be doing some experimenting. There are also quite a few capacitors of between 400v and 600v that should come in handy. I intend to use the main PSU transformer I removed as a mid range transformer, and the flyback in series with a capacitor as a second HV unit (as you have described). I'll probably have to wind a custom primary onto the flyback, and I hope it hasn't burnt out. If so, I'll just remove the ferrite core and wind my own.
Could I use potting compound as insulation in this case? I have seen it recommended in the patent for a stun gun I looked at.
J
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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
c0deblue
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From:
Registered: JAN 2001
posted 03-14-2001 02:08 PM
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If I envision your circuit correctly, the 3055 is simply being used as a switch to ground for the HV primary, much as the points in an automotive distributor are used to interrupt current through the ignition coil. The HV primary acts as a load in what essentially is a DC short when the 3055 switch is conducting, which imposes a terrific current drain equivalent to (almost) shorting the battery when the 3055 base is driven high. The only things saving this circuit from self-destruction are the current-limited supply and the inductive reactance of the HV primary (which without the core would present almost zero DC resistance whether it was 10 turns or 40). What's happening is that with twice as many primary turns inductive reactance is double and recovery times are shorter resulting in higher frequency (a tuned circuit of sorts, albeit a crude one). If I had to guess I'd say that in either case (10 turns or 20) the battery is being loaded beyond its ability to supply current at the rated voltage. This is consistent with your observation that frequency increased with 20 turns while HV output remained unchanged. Measure the supply (battery) voltage under both operational conditions to confirm this theory.
The advantage of using a pulse oscillator is that the low duty cycle pulse train driving T-1 imposes a minimal current requirement, while the high saturation rate and low reluctance of ferrite make for lower rms current/shorter recovery time thus allowing high amplitude pulses to the T-2 primary. This is why reducing (within reason) the number of turns in the T-2 primary to increase HV output has little effect on circuit performance.
Trying to use the secondary of a TV flyback as-is probably won't give good results. The best flybacks typically are designed to withstand voltages only up to about 50KV - their construction just isn't suited to withstanding impulse gradients greater than this.
In terms of insulation the principal function of potting compounds is to exclude air and moisture. However, with high voltage the potting material itself must exhibit high insulative properties and dielectric strength. In general, the (unfilled) RTV silicone formulations are a pretty good choice for HV work, but only when properly degassed and applied under vacuum conditions (improperly used, some silicones can actually entrain water). The corona dopes (mentioned earlier) are a good alternative. In conjunction with good insulation, HV performance will also be improved if the coil is wound with a small space between adjacent turns, although this is only practical if one has access to a coil winding machine or a lathe with precision feed.
Muffscre's digits
New Member
Posts: 28
From: surrey,BC Canada
Registered: NOV 2000
posted 03-31-2001 12:20 AM
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make sher that it is under 50mA current.
with 50mA and 30V and up it can kill.
so 9v with 159mA will not kill
and 110V and 5mA will not kill
but 110V and 70mA will kill
[This message has been edited by Muffscre's digits (edited March 31, 2001).]
J
Moderator
Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-31-2001 12:48 PM
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Have you got a reference for this? I'm not disbelieving you, I was under the impression that a number of conditions were involved (e.g. skin dryness, position of electrodes/current path, duration) in the conductivity of the human body, and there is no exact set minimum voltage required to kill someone.
J
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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
[This message has been edited by J (edited March 31, 2001).]
c0deblue
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Posts: 229
From:
Registered: JAN 2001
posted 03-31-2001 01:48 PM
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The only blanket statement that can be made on this subject is that as little as 16 mA AC directly through the heart muscle can cause ventricular fibrillation. DC current has a clamping effect and brief shocks are therefore not as dangerous to the heart. Similarly, large AC currents are less dangerous in this respect (but do more tissue damage). The following may be helpful:
=============================================
Physiological Effects Of Electric Current Densities On The Human Body
1 - 5 mA = Threshold of Sensation
5 - 10 mA = Mild Sensation
10 - 20 mA Cannot Let Go/Painful
20 - 30 mA = Muscular Paralysis/Severe Shock
30 - 50 mA = Breathing Upset/Labored
50 - 75 mA = Extreme Breathing Difficulty
75 - 100 mA = Ventricular Fibrillation
100 - 200 mA = Death
200 - 1000 mA = Severe Burns/Breathing Stops
(Note that the above values are density averages. As little as 16 mA *directly* through the heart muscle is sufficient to cause ventricular fibrillation.)
The chart shows the effect of various current densities on the human body. Voltage is not the prime consideration, although it takes voltage to to produce the current flow. The amount of shock current depends on the body resistance between the points of contact and the skin condition, that is, moist or dry. For example the internal resistance between the ears is only 100 ohms (less skin resistance), while from hand to foot the internal resistance is close to 500 ohms. Skin resistance may vary from about 1,000 ohms for wet skin to over 1/2 Megohm for dry skin, and is even lower for AC.
Shock becomes more severe as current rises. At values as low as 20 mA breathing can become labored, and as the current approaches 100 mA, ventricular fibrillation of the heart occurs. Above 200 mA, the muscular contractions are so severe that the heart is forcibly clamped during the shock. This clamping protects the heart from going into ventricular fibrillation and the victim's chances for survival are good if the victim recieves immediate medical attention.
=============================================
And a website that gives some information:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/shock.html
Azazel
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Posts: 91
From: ...
Registered: SEP 2000
posted 04-11-2001 09:50 AM
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so... any sites or what ?
Anthony
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Posts: 2306
From: England
Registered: SEP 2000
posted 04-13-2001 01:42 PM
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Umm, two things:
a) putting bpoth live and neutral wires on the same metal rod will just short them.
b)You stand a good chance of killing someone with a full curent belt off the mains like that.
BoB-
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From:
Registered: SEP 2000
posted 04-13-2001 05:31 PM
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"there are 2 things you can do with this*****
1. smack somone near a power outlet
2. stick in dirt and move up and down like your having sex with the ground, this will make worms come to the surface (good if you have reptiles)..."
Pretty sure they use light vibrations to simulate rain to cause worms to come to the surface.
Anthony
Moderator
Posts: 2306
From: England
Registered: SEP 2000
posted 04-13-2001 09:47 PM
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First of all, running head first into a brick wall is not the best way to guarantee your longevity.
There's information on the effects of electrical current on humans right in this very thread. 240v will drive a current of 240mA through wet skin. Referring to the above chart we can see that this equals death. Mains current is also capable of blowing large chunks of flesh out of your body.
If you don't think it will kill you then be my guest to seperate the ends of a cord and touch one to each of your niples.
-phreakyphool-
New Member
Posts: 1
From: Surrey
Registered: APR 2001
posted 05-01-2001 01:23 AM
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Here is a small zapper schematic I found at school, it's big!: (loads in new window)
SCHEMATIC
It has a low battery warning and a ready LED
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-PhreakyPhool-
[This message has been edited by -phreakyphool- (edited May 01, 2001).]
c0deblue
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Posts: 229
From:
Registered: JAN 2001
posted 05-01-2001 03:19 AM
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Hate to disillusion you, phreakyphool, but I think whoever designed this thing and called it a "Zapper" must have been playing some kind of joke. The first transistor (and zener diode) forms a simple voltage regulator to reduce the 9 volt supply to about 6 volts. The second transistor causes the red LED to light when battery voltage goes below 7.2v. The 555 timer is set up as an oscillator producing a 30KHz square wave (at about 6 volts peak to peak), which causes the green LED to light. The copper pipe "hand-holds" carry the same 555 output that drives the LED, but with a 1K resistor in series. The only result of gripping the copper "hand holds" *might* be (under the most favorable conditions) that you would act as a sort of current shunt and cause the green LED to dim slightly.
I doubt you'd feel more than the mildest tingle (if that) if you were clutching this device while sitting in a bath with your hands covered with conductive gel.
Mr Cool
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Posts: 991
From: None of your bloody business!
Registered: DEC 2000
posted 05-06-2001 06:57 AM
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Marx generators are cool, but couldn't be made very portable for a taser:
http://home.earthlink.net/~jimlux/hv/marx.htm for more info.
I made one with 30 surplus 10kV, 0.06uF capacitors, so it could make 300,000 volts. That equals 90 joules, all discharged in less than 1uS. That means it has a peak power of OVER 90 MILLION WATTS!
If you make one like this, wear ear protection. It's very loud!
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 05-06-2001 01:59 PM
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Marx Generators kick ass! those things are cool! and loud as hell!
sealsix6
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Posts: 154
From: NYC,NYC,USA
Registered: NOV 2000
posted 05-07-2001 08:56 PM
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check out http://www.wpi.edu/~jccook/ph1121.html
protical sun
New Member
Posts: 27
From: shove it
Registered: JAN 2001
posted 05-22-2001 12:46 PM
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try using the innerds of a disposable camera. it more stuns the person than anything else, just enough time to hit them with a bobby club or something.
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 05-22-2001 05:20 PM
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the camera flash will not perece clothing though
Igenx
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From: No Fucking Way
Registered: SEP 2000
posted 05-22-2001 05:40 PM
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I have a flash unit off of an old camera (one of the ones that had the big detachable flash) that I bought intending to rip apart. Thing still worked, so I just hooked up a pair of leads so I could fry electronics with it. While it does deliver a hell of a shock (believe me on this one ) it isn't enough to put you down. I zapped myself a few times intentionally (and unintentionally) and I never lost total control. Only caused twitching, which is bad if your target has a gun.
O yeah... Hook up a pair of wire leads to a cork with a pair of fishhooks. Since a "real" tazer needs physical contact anyways, it shouldn't be a problem to get close enough to jab the target.
New Member
Posts: 6
From:
Registered: NOV 2000
posted 03-08-2001 10:23 PM
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I have been experimenting with making a homemade tazer. Even though mine works partially sometimes, I'm wondering if any of you have made a tazer before? And if so could you illustrate the plans to me?
SATANIC
Frequent Poster
Posts: 237
From: australia
Registered: SEP 2000
posted 03-08-2001 10:41 PM
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how did you make it? i've often wanted a tazer, but i think they're illegal here (aus) a home made one would do fine though, they have the advantage of being untraceable
ILLuSion
New Member
Posts: 6
From:
Registered: NOV 2000
posted 03-08-2001 10:52 PM
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I just looked at a couple designs of tazers, took a few of my friend's tasers apart and started from scratch from there.
Agent Blak
Frequent Poster
Posts: 766
From: Sk. Canada
Registered: SEP 2000
posted 03-08-2001 11:22 PM
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how many volts is it?
does it look like a Peice of junk?
how long idid it take you to build with your reverse engineering techniques?
------------------
A wise man once said:
"...I Am Not Much of a Dancer But,
Just Wait Till The Fucking Begins"
Agent Blak-------OUT!!
CragHack
Frequent Poster
Posts: 618
From:
Registered: DEC 2000
posted 03-09-2001 03:39 PM
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you gotta watch out for homeade tazors dude. you hit the victim in the middle of the chest and you could possibly pass a current through the heart. bad news if you only wantesd to knock them down.
------------------
...Æ
ILLuSion
New Member
Posts: 6
From:
Registered: NOV 2000
posted 03-10-2001 03:27 PM
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It is 200,000 volts I think. Yes I know Homemade Tasers are sometimes bad news. I have taken many steps on precaution for them
ASSGREMLIN
New Member
Posts: 16
From: NIL
Registered: MAR 2001
posted 03-12-2001 01:32 AM
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I have a book that shows how to make a tazer, and a load of other crap (lasers, ultrasonic "pain generators," etc.) and i would love to post the plans, but i don't have a scanner For anyone interested the book is called "Build Your Own Laser, Phaser, and Ion Ray Gun." The author basically bought a bunch of the plans from Information Unlimited Inc. ( www.amazing1.com ) and tested them. And although the name sounds cheesy, I've looked at the schematics, and they seem valid.
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 03-12-2001 03:06 PM
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that is a bull shit site and If you buy a laser from them they will send you a blinking led I know people that have orderd from there.
vehemt
Frequent Poster
Posts: 580
From: Canada
Registered: SEP 2000
posted 03-12-2001 05:02 PM
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Amazing1.com isnt a bullshit site, but they do have incredibly high prices.
The author of "Build Your Own Laser, Phaser, and Ion Ray Gun", Robert Ianini(spelling), is the owner of Information Unlimited. He wrote the book nearly 20 years ago(his company existed back then too, the book was somewhat of a plug for the company as a source of parts for certain projects).
Its not bullshit, just really, really, really, old(proven) technology.
Im not saying you should buy anything from Information Unlimited, but what I am saying is that the book is just fine(just borrow it from a library and make some photocopies of the pages you want the plans for). In general information Unlimited is out to get your money though.
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 03-12-2001 05:35 PM
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just dont buy their kits and expect their descriptions to be accurate.
ASSGREMLIN
New Member
Posts: 16
From: NIL
Registered: MAR 2001
posted 03-12-2001 10:58 PM
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Actually, their descriptions *are* acurate (in the book) and although its old, it works.
J
Moderator
Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-13-2001 07:34 AM
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Illusion, do you have any schematics? If not, can you describe the circuit (i/e this block does this etc)? I'm building a stun gun (all info including schematics and current results on my site), I've found the difficult part of the circuit is the HV transformer. I've wound my own, but from descriptions of other circuits I don't think I have a high enough step up ratio.
J
------------------
"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
c0deblue
Frequent Poster
Posts: 229
From:
Registered: JAN 2001
posted 03-13-2001 02:37 PM
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J: The HV transformer is pretty easy, but you have to take special precautions to achieve very high voltages without flashover.
Greatest circuit efficiency is obtained with a high frequency primary oscillator driven at 20KHz or higher.
For the output transformer, start with a piece of ferrite rod to use as a core - a piece of the rod from an AM radio antenna works fine (round) or you can use a section of the ferrite core from a TV flyback transformer (usually square). Wrap this with Mylar and wind the coil directly on that. You don't need a "closed" transformer core - a rod-wound solenoid configuration will provide all the coupling you need for this application.
Don't exceed about 2 inches for the coil length as the voltage differential between the ends of adjacent coil layers will be too great. Use corona dope (TV repair supply) on each winding and cover this with .001 Mylar tape. Pay special attention to insulating the ends of each winding layer, as this is the weakest spot electrically.
Overwind the secondary - that is, calculate a turns ratio for 300-400KV - this isn't critical. When completed, test the unit using controlled-gap regulation. The gap distance will limit the voltage output and by slowly increasing the gap you'll quickly find the point at which internal flashover begins. Simply fix the gap regulator distance at a point short of this flashover or insulation breakdown point and you're all set.
Peak to peak output voltage is estimated at the rate of 75KV per inch spark gap (spherical electrodes at 760mm Hg atmosphere and 25C temperature).
Using care in winding and the best insulation materials I've achieved 5 inch blue sparks (almost 400KV) from coils as small as 2.5"L x 1.5"D overall, from a primary circuit powered by two 9V "clip" batteries. Output was limited only by the insulation materials - with vacuum impregnation output voltage of over 500KV could easily be realized.
J
Moderator
Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-13-2001 07:24 PM
--------------------------------------------------------------------------------
My transformers have so far been limited by the size of the RM10 core kits I'm using. I can wind 1500 turns of 0.125mm ECW on one of these before there is no room for the primary winding. I have experimented using primaries of 10 turns 1mm ECW, and 20 turns of 0.25mm. The 20 turn primary allows the transformer to operate at a higher frequency, although the spark length is nearly the same as the 10 turn primary. Is there a set minimum/ideal number of turns for the primary to get the maximum efficiency?
I might go skip raiding later, there's usually a monitor or two in the university skips ;-) Thanks for the info, I always assumed that a closed core was needed. Is there a possible substitute for the mylar? What about some insulation tape?
Is the order of windings critical? I wind the secondary first, then the primary. This way I can play around with different ratios easilly.
J
------------------
"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
c0deblue
Frequent Poster
Posts: 229
From:
Registered: JAN 2001
posted 03-13-2001 09:31 PM
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J: Your statement about a 20 turn primary allowing higher frequency operation leads me to suspect you may be using the primary winding of your HV transformer as part of a tuned oscillator circuit. This will work, but output is likely to be limited and current consumption will be fairly high.
The units I've built are 2-transformer circuits utilizing a stand-alone pulse oscillator with its own closed core transformer (also ferrite), and a secondary of between 300-600 Volts. This can be wound using a traditional "E" core, but my best results were obtained with a ferrite toroid. The 300-600V pulse output in turn drives the primary of the ferrite rod HV transformer, capacitively coupled (~0.5uF/600VAC) to limit input current and prevent core saturation. This system also provides a testbed for experimenting with different HV coil designs, since these can simply be interchanged.
Output of the oscillator stage is a 22-25KHz short-duration pulse train at almost the supply voltage (about 16V in this case) driving the toroidal transformer (call this T-1). The T-1 secondary is a (nominal) 450 Volt pulse. With the HV primary as a load in series with the 0.5uF/ 600VAC capacitor, the T-1 output waveshape exhibits a short leading edge but a damped trailing edge (decay curve) due to core reluctance and capacitive effect.
The HV transformer (T-2) is simply a solenoid-wound coil (as previously stated) with the primary wound outside (or adjacent to) the secondary winding. Maximum potential (turns ratio) output can thus be varied by changing the number of primary turns, without in any way affecting the output of T-1.
As to the question of insulation, there's really not much room for compromise when dealing with high voltage. Ordinary PVC electrical tape definitely won't withstand the inter-layer (much less the layer-end) differentials that exist in transformers of such compact design (a problem that doesn't exist with physically large, single-wound Tesla coils). The Mylar sheet used for the core liner ought to be available as drafting film. For the Mylar tape try a specialty supplier such as Jolitape http://www.jolitape.ca/transformer_motor.htm They'd probably be more than willing to supply samples for your "pre-production prototype" or "R&D program".
J
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From: United Kingdom
Registered: SEP 2000
posted 03-14-2001 06:33 AM
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I'm not using a tuned circuit. It is a multivibrator driving a 2N3055 with the output. The primary is connected between the collector and the positive supply rail.
I don't know why the 20 turn primary causes it to operate well at a higher frequency. The 10 turn seems to have an optimum frequency, after which it just gets worse and eventually won't operate.
The nights skip raiding has yielded a flyback out of a colour monitor, so later on I'll be doing some experimenting. There are also quite a few capacitors of between 400v and 600v that should come in handy. I intend to use the main PSU transformer I removed as a mid range transformer, and the flyback in series with a capacitor as a second HV unit (as you have described). I'll probably have to wind a custom primary onto the flyback, and I hope it hasn't burnt out. If so, I'll just remove the ferrite core and wind my own.
Could I use potting compound as insulation in this case? I have seen it recommended in the patent for a stun gun I looked at.
J
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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
c0deblue
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From:
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posted 03-14-2001 02:08 PM
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If I envision your circuit correctly, the 3055 is simply being used as a switch to ground for the HV primary, much as the points in an automotive distributor are used to interrupt current through the ignition coil. The HV primary acts as a load in what essentially is a DC short when the 3055 switch is conducting, which imposes a terrific current drain equivalent to (almost) shorting the battery when the 3055 base is driven high. The only things saving this circuit from self-destruction are the current-limited supply and the inductive reactance of the HV primary (which without the core would present almost zero DC resistance whether it was 10 turns or 40). What's happening is that with twice as many primary turns inductive reactance is double and recovery times are shorter resulting in higher frequency (a tuned circuit of sorts, albeit a crude one). If I had to guess I'd say that in either case (10 turns or 20) the battery is being loaded beyond its ability to supply current at the rated voltage. This is consistent with your observation that frequency increased with 20 turns while HV output remained unchanged. Measure the supply (battery) voltage under both operational conditions to confirm this theory.
The advantage of using a pulse oscillator is that the low duty cycle pulse train driving T-1 imposes a minimal current requirement, while the high saturation rate and low reluctance of ferrite make for lower rms current/shorter recovery time thus allowing high amplitude pulses to the T-2 primary. This is why reducing (within reason) the number of turns in the T-2 primary to increase HV output has little effect on circuit performance.
Trying to use the secondary of a TV flyback as-is probably won't give good results. The best flybacks typically are designed to withstand voltages only up to about 50KV - their construction just isn't suited to withstanding impulse gradients greater than this.
In terms of insulation the principal function of potting compounds is to exclude air and moisture. However, with high voltage the potting material itself must exhibit high insulative properties and dielectric strength. In general, the (unfilled) RTV silicone formulations are a pretty good choice for HV work, but only when properly degassed and applied under vacuum conditions (improperly used, some silicones can actually entrain water). The corona dopes (mentioned earlier) are a good alternative. In conjunction with good insulation, HV performance will also be improved if the coil is wound with a small space between adjacent turns, although this is only practical if one has access to a coil winding machine or a lathe with precision feed.
Muffscre's digits
New Member
Posts: 28
From: surrey,BC Canada
Registered: NOV 2000
posted 03-31-2001 12:20 AM
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make sher that it is under 50mA current.
with 50mA and 30V and up it can kill.
so 9v with 159mA will not kill
and 110V and 5mA will not kill
but 110V and 70mA will kill
[This message has been edited by Muffscre's digits (edited March 31, 2001).]
J
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Posts: 602
From: United Kingdom
Registered: SEP 2000
posted 03-31-2001 12:48 PM
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Have you got a reference for this? I'm not disbelieving you, I was under the impression that a number of conditions were involved (e.g. skin dryness, position of electrodes/current path, duration) in the conductivity of the human body, and there is no exact set minimum voltage required to kill someone.
J
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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman
[This message has been edited by J (edited March 31, 2001).]
c0deblue
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Posts: 229
From:
Registered: JAN 2001
posted 03-31-2001 01:48 PM
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The only blanket statement that can be made on this subject is that as little as 16 mA AC directly through the heart muscle can cause ventricular fibrillation. DC current has a clamping effect and brief shocks are therefore not as dangerous to the heart. Similarly, large AC currents are less dangerous in this respect (but do more tissue damage). The following may be helpful:
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Physiological Effects Of Electric Current Densities On The Human Body
1 - 5 mA = Threshold of Sensation
5 - 10 mA = Mild Sensation
10 - 20 mA Cannot Let Go/Painful
20 - 30 mA = Muscular Paralysis/Severe Shock
30 - 50 mA = Breathing Upset/Labored
50 - 75 mA = Extreme Breathing Difficulty
75 - 100 mA = Ventricular Fibrillation
100 - 200 mA = Death
200 - 1000 mA = Severe Burns/Breathing Stops
(Note that the above values are density averages. As little as 16 mA *directly* through the heart muscle is sufficient to cause ventricular fibrillation.)
The chart shows the effect of various current densities on the human body. Voltage is not the prime consideration, although it takes voltage to to produce the current flow. The amount of shock current depends on the body resistance between the points of contact and the skin condition, that is, moist or dry. For example the internal resistance between the ears is only 100 ohms (less skin resistance), while from hand to foot the internal resistance is close to 500 ohms. Skin resistance may vary from about 1,000 ohms for wet skin to over 1/2 Megohm for dry skin, and is even lower for AC.
Shock becomes more severe as current rises. At values as low as 20 mA breathing can become labored, and as the current approaches 100 mA, ventricular fibrillation of the heart occurs. Above 200 mA, the muscular contractions are so severe that the heart is forcibly clamped during the shock. This clamping protects the heart from going into ventricular fibrillation and the victim's chances for survival are good if the victim recieves immediate medical attention.
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And a website that gives some information:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/shock.html
Azazel
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Posts: 91
From: ...
Registered: SEP 2000
posted 04-11-2001 09:50 AM
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so... any sites or what ?
Anthony
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Posts: 2306
From: England
Registered: SEP 2000
posted 04-13-2001 01:42 PM
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Umm, two things:
a) putting bpoth live and neutral wires on the same metal rod will just short them.
b)You stand a good chance of killing someone with a full curent belt off the mains like that.
BoB-
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Posts: 679
From:
Registered: SEP 2000
posted 04-13-2001 05:31 PM
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"there are 2 things you can do with this*****
1. smack somone near a power outlet
2. stick in dirt and move up and down like your having sex with the ground, this will make worms come to the surface (good if you have reptiles)..."
Pretty sure they use light vibrations to simulate rain to cause worms to come to the surface.
Anthony
Moderator
Posts: 2306
From: England
Registered: SEP 2000
posted 04-13-2001 09:47 PM
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First of all, running head first into a brick wall is not the best way to guarantee your longevity.
There's information on the effects of electrical current on humans right in this very thread. 240v will drive a current of 240mA through wet skin. Referring to the above chart we can see that this equals death. Mains current is also capable of blowing large chunks of flesh out of your body.
If you don't think it will kill you then be my guest to seperate the ends of a cord and touch one to each of your niples.
-phreakyphool-
New Member
Posts: 1
From: Surrey
Registered: APR 2001
posted 05-01-2001 01:23 AM
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Here is a small zapper schematic I found at school, it's big!: (loads in new window)
SCHEMATIC
It has a low battery warning and a ready LED
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-PhreakyPhool-
[This message has been edited by -phreakyphool- (edited May 01, 2001).]
c0deblue
Frequent Poster
Posts: 229
From:
Registered: JAN 2001
posted 05-01-2001 03:19 AM
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Hate to disillusion you, phreakyphool, but I think whoever designed this thing and called it a "Zapper" must have been playing some kind of joke. The first transistor (and zener diode) forms a simple voltage regulator to reduce the 9 volt supply to about 6 volts. The second transistor causes the red LED to light when battery voltage goes below 7.2v. The 555 timer is set up as an oscillator producing a 30KHz square wave (at about 6 volts peak to peak), which causes the green LED to light. The copper pipe "hand-holds" carry the same 555 output that drives the LED, but with a 1K resistor in series. The only result of gripping the copper "hand holds" *might* be (under the most favorable conditions) that you would act as a sort of current shunt and cause the green LED to dim slightly.
I doubt you'd feel more than the mildest tingle (if that) if you were clutching this device while sitting in a bath with your hands covered with conductive gel.
Mr Cool
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Posts: 991
From: None of your bloody business!
Registered: DEC 2000
posted 05-06-2001 06:57 AM
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Marx generators are cool, but couldn't be made very portable for a taser:
http://home.earthlink.net/~jimlux/hv/marx.htm for more info.
I made one with 30 surplus 10kV, 0.06uF capacitors, so it could make 300,000 volts. That equals 90 joules, all discharged in less than 1uS. That means it has a peak power of OVER 90 MILLION WATTS!
If you make one like this, wear ear protection. It's very loud!
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 05-06-2001 01:59 PM
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Marx Generators kick ass! those things are cool! and loud as hell!
sealsix6
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Posts: 154
From: NYC,NYC,USA
Registered: NOV 2000
posted 05-07-2001 08:56 PM
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check out http://www.wpi.edu/~jccook/ph1121.html
protical sun
New Member
Posts: 27
From: shove it
Registered: JAN 2001
posted 05-22-2001 12:46 PM
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try using the innerds of a disposable camera. it more stuns the person than anything else, just enough time to hit them with a bobby club or something.
PYRO500
Moderator
Posts: 1465
From: somewhere in florida
Registered: SEP 2000
posted 05-22-2001 05:20 PM
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the camera flash will not perece clothing though
Igenx
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From: No Fucking Way
Registered: SEP 2000
posted 05-22-2001 05:40 PM
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I have a flash unit off of an old camera (one of the ones that had the big detachable flash) that I bought intending to rip apart. Thing still worked, so I just hooked up a pair of leads so I could fry electronics with it. While it does deliver a hell of a shock (believe me on this one ) it isn't enough to put you down. I zapped myself a few times intentionally (and unintentionally) and I never lost total control. Only caused twitching, which is bad if your target has a gun.
O yeah... Hook up a pair of wire leads to a cork with a pair of fishhooks. Since a "real" tazer needs physical contact anyways, it shouldn't be a problem to get close enough to jab the target.