Arming yourself via Radio Shack?

[Nico]

Here's a brain storming exercise ...

You have to equip yourself for self-defense and/or -offense by using only what is available at the local Radio Shack. Let's say you have like $50 to spend, but no lab or anything to work at, so everything would have to be from scratch.

Myself, I'd probably just have to buy a megaphone or something and use it as a club, but I'm sure you folks will be much more creative. :)

[PYRO500]

I could think of better places to buy things with 50$ than radiao shack of course you could get high power flashlights, and clubbing instruments ( a waste of money and cheap plastic). If I were desprate and needed some tools of the trade badly then I'd take that 50$ and go nextdoors in the mall to sears and buy a pair of bolt cutters and steal something more worth while like stealing a gun at one of those shitty ungarded fleamarkets. with a gun a clip of ammo and some wits along with luck that most seem to push too far you could concevably build yourself back up from the slums also you could spen that 50$ at a secondhand store and get some clean clothes and get yourself a real job and from there on your pretty much set.

[Jhonbus]

My guess is that $50 would be plenty to build some sort of taser. An ergonomic shaped one like the commercial ones would be difficult, so building it into a long plastic pole would be the best bet. AFAIK, some police forces use just such a device - it looks like the usual "nightstick" but has two prongs on the end for the discharge.

[J]

Or you could go into all the camera shops in town and ask for used disposable cameras. Take out the flash units, modify them by wiring several caps in parralel, add probes and a case, and you have a potentially lethal electric shock weapon. All for absolutely nothing, including free batteries :) But if you're prepared to be lethal, I'd personally just buy a knife.

[Anthony]

I think the baton like tazer is most likely a cattle-prod.

[pyromaniac_guy]

J,
I dont know about other vendors, but at least for kodak, they require photo shops to return the disposable cameras back to them. they arent really ment to be disposable, just cheap enough that you dont worry if you loose one... The OEM's try to recylce them things as much as possible. HOWEVER, there really isnt a need to get alot of them together, just get one, all you need is one charging circuit. Add a few extra electrolytic caps from radioshack and thats all you need. Only problem with such a device however is that most likely you will need direct skin contact for it to work, as it doesnt take alot to insulat a few hundred volts. I dont know if these things use series injection triggering, or if there is an extrenal trigger wire on the flashlamp. (or is triggering is uesd at all, however I assume it is) if you could find a charger with series injection triggering this would be best, so that you would get a nice higher voltage spike to start conduction in cases where the target provides an unsuitably high resistance. (no pun intended)

[dragon]

This is a tad off topic, but dose anyone know of a way to wind a pulse transformer. As used for the output of a stun gun.

I.e. most are wound and potted in a vacuum for insulation. I did have a file for one. Wound buy dipping it in wax after each winding.

i.e. any way to improvised a way to pot it under a vacuum at home.

[pyromaniac_guy]

it's a little less convinient than a solid potting, but you could always build the transformer in an acrylic container and then pot under liquid, such as mineral oil. Then seal up the acrylic (so long as this isnt for a high duty cycle aplication where you will be generating heat)

[dragon]

Yep oil sounds a good idear, I could pot them in in oil in a small potting box and seal it with epoxy. It wont be under a high duty cycle as its for a stun gun.

failling that. I thort of nipping over to france, one day picking up some duty free and a load of stunguns. then stiping them dumping the cases and posting the pcbs and pulse transformers in different pakages to my self in the uk.

im sure they would clear customs then.

[PYRO500]

Hand held stun guns in general aren't a whole lot more efective than a blade. as far as radio shack goes most of the electronics stuff I really want they don't carry anymore they now sell alot of hi-teck shit like cell phones but when you need a special mosfet transistor, no you have to order it to your house. also they do not carry the types of caps you need to charge witha disposable camera flash those aren't really avalable at many places. as far as making a stun gun from scratch sure it's possible but considering you need to have a case a circuit schematic (or knowledge of electronics, enough to make your circuit from scratch) and a few select parts that you won't find at radio shack and you'll never build anything that can meet commercial grade beacuse all your likely to do from radio shack is build a little shocker device that will make an enemy laugh.

[dragon]

true but i can wind the first sep up transformer on a core kit and you can get hv cap from rs in the uk easy. you can often find hv caps in old tv`s and monitors too.

but i must admit not much down tandys(radio shack in the uk) now as theye stoped stoking many parts here too.

making te efective is more to do with get the pulse right and not the votage.

[Nico]

True, there are a lot of places with more 'bang for your buck' than Radio Shack. I was just wondering if there was something I was missing.
PYRO500, I like your Sears idea. Sort of like laddering up when buying a home. :)

[J]

Different shops have different policies on recycling. My local one just throws them away, I've got them to save the cameras for me :-) Current new price on a 120uF 330V cap is about £1.50, so you're saving a lot of cash when building up a medium sized bank (as I'm currently doing).

On this note, I've just modified a flash unit to make an effective blasting box, using a thyristor to switch the high current. This will reliably make thin copper wire explode, full details and video will be up soon.

Yes, the flash units have a trigger transformer, which pulses at a few KV to ionize the gas in the flash tube. But if you used sharp electrodes this isn't necessary.

Dragon, check out my website for info on winding a pulse transformer, and full details (minus the case) for a homemade stungun. Vacuum potting isn't required if you're careful, and the voltage is kept to 50kv or so. I used silicone sealant for mine. Oil should be better, but very messy. The containment vessel will add size to your coil too.

[xoo1246]

I have a cirucit from a flash-unit, it operates at around 300 volts and is good enough to make thin iron strands explode with a sharp crack. The cables I use aren't exactly isulated to take 300 volts so I keep chocking myself. One gets a little bit stiff in the arms. <img border="0" title="" alt="[Wink]" src="wink.gif" />

[xyz]

You have to get quite a lot of caps on a camera flash charger circuit to get any decent shock out of it (unless you use pulse caps or very large caps). I have been shocked with 5 of the standard 330volt 120uf caps in parallel and it burned two small marks into my hand but other than making me drop the caps and hurting like @#$% for less than a second it was no big deal. I would use at least 10 flash caps and connect them in series (wiring caps in series increases voltage, wiring them in parallel increases capacitance, and a combination of the two can be made to get some of both increased)

[PYRO500]

while 330-350V may not hurt excruciatingly bad at a glancing touch, if you get stuck on one of those little caps you will have some pain on your hands. more capacitance the more energy the device can put out. the main problem with these little caps is the low voltage causes the skin resistance to block the fairly large amount of energy (for energy absorbed into the body 30J is usually lethal) in these caps (anywhere from 2J to 10J depending on the size of the flash) I think the easyest way to overcome skin resistance is to use sharp needle probes on the end, that will really hurt I can gurante.

<small>[ July 20, 2002, 08:15 AM: Message edited by: PYRO500 ]</small>

[Jumala]

Hallo xyz,
be careful with those capacitors. It is said that currents higher than 30 mA through your body crossing your hard can be lethal.
I think you have felt that the shock had several ampere but only from one finger to another. (your luck)If it had passed the hard you would need some subterran furniture.
The skin resistance is not the biggest problem for the 350 V but some cloth can be.
But pyro500 is right, using needle electrodes gives a pain like hell at 350V.
Another problem is that a weapon buildt in that way gives only one shock. Then the cap must be reloaded for the next.

[xyz]

Sure, 30mA can kill if the electodes are stuck either side of your heart inside your chest but it takes a lot more than that to kill someone usually. Pyro, the current from 5 of them in parallel burns tiny cauterized holes through the skin instantaneously and overcomes skin resistance. I have emptied the entire charge from a single one deliberately into my hand (took about 3 seconds) which hurt a lot and gave me pins and needles in my hand for 30 seconds afterward but had no other effects. I also know someone else who deliberately put a finger from each hand on the terminal of a camera flash cap (current passes through both arms, chest, and heart) and said it hurt more than normal but no other effect. Camera flash caps are no danger to people as I know many people from our school who have shocked themselves or others on the face, neck, ears, etc. You have to remember that the only parts of the body which are greatly effected by electricity are the heart and brain and that a shock from a cap is delivered only on the skin and flesh between the terminals (usually about 1cm apart).

Edit: Jumala, a capacitor weapon can charge quickly with a good charger and battery, my 3 volt charger has a 3.5 volt 8 amp NiCd battery that I got out of a cordless electric toothbrush and this charger can charge a standard photo flash cap in about 1-2 seconds. A 6 volt charger( from the flash attachments that you put on cameras) and a 6 volt lantern battery would make a good one but I have yet to get hold of a 6 volt charger.

<small>[ July 19, 2002, 11:01 PM: Message edited by: xyz ]</small>

[PYRO500]

all capacitors that store a charge can be lethal! geting in the habit of touching them is like playing russian roulette, if you want to do anything besides digital electronics get in the habit of NEVER touching any capacitor's terminals.

[xyz]

I'm not talking big caps here Pyro, I would never touch anything larger than a 330v 120uf photo flash cap and even then I know what they feel like know and probably won't do it again :) . I did all this stuff several months ago and haven't touched a cap since. Also, I'm not the one who put a finger from each hand on one and If I was going to touch any cap at all I would make sure that it was a 330v 120uf photo flash or smaller and that I was only shocking a hand or a finger. I have only ever put a cap on a finger or a hand and nowhere else and I am not trying to encourage people to go and start touching charged capacitors, just saying that you need 5-10 or so photo flash caps for any kind of shocker if you want good results.

Edit: I would also like to add that I am definitely NOT in the habit of touching cap terminals no matter what size the cap is (I would have thought that the fact I own a coke can sized cap for my coil driver and I am still alive means that I have obviously not tried touching it). I avoid the terminals when doing electronic work. The only reason that I shocked myself deliberately a few times was to see what worked best for a shocker and what they felt like (rest assured, I had shocked someone else before I tryed it on myself).

<small>[ July 19, 2002, 11:44 PM: Message edited by: xyz ]</small>

[PYRO500]

It is never a good idea to touch any capacitor especially any over half a joule, anything more than a quartar joule is not gonna feel good if it can overcome skin resistance. I don't think everyone that meses with capacitors truly realizes the dangers involved in them. Capacitors are usually much more dangerous than direct current beacuse of the current that can run through you in the short time. anything over 50-75 volts has the power to easily overcome skin resistance and either burn or kill you. in the case with capacitors the high currents discharging through your skin is sometimes possible to explode flesh and amputate limbs now this is at high power but smaller caps can do so at a smaller scale. I have my 2 capacitor 2,000J electrolytic bank and I can tell you if your fingers touched the electrodes they'd probobly be missing some flesh and look like they had a firecracker go off in them.
I think I should say that any touch to any power capacitor (not digital circuit ones) should be considered a severe risk of injury.

[xyz]

That's why I don't do it anymore :) , other people age 14 like me usually do far more dangerous things than touch caps, like some idiot who found a detonator at a quarry and stuck a bit of burning paper in the fuse hole to see what would happen (true story, honest!)

Edit: Also, is there much advantage to pulse caps as opposed to electrolytics for shockers? If yes then are the homemade kind any good? (the oil filled ones with aluminium sheet or foil for the plates and polyethylene as a dielectric)

<small>[ July 20, 2002, 12:55 AM: Message edited by: xyz ]</small>

[PYRO500]

Yes, pulse caps generally discharge alot faster than electrolytics, it is due to a number of things i'm not gonna get into here. Those home made tesla coil capacitors usually have small energy density for their size due to manufacturing problems. in the pulse capacitor manufacturing plants they have rolls of special dielectric film made especially for precision thinkness and is rolled very flat in nearly sterile enviroments with metal foil. there are really no ways around buying large energy storage capacitors. any capacitor you'll make will be at best unpredictable and not very dense in it's energy storage, let alone the fact that the ESR will be alot higher meaning slower pulse.
For shocker applications electrolytic capacitors will usually work fine. in fact photoflash capacitors are precise electrolytic capacitors and they work well.

As far as types of electrolytics go there are 3 main grades of electrolytic capacitors. The types are computer grade, inverter grade, and pulse rated capacitors.
The computer grade should do fine for your shocker applications but beware they are not designed for use where they will be rapidly shorted and will suffer reduced lives if they are although some can last a fair number of discharges I guess it's up to you how long you want your caps to last.

I think that you should be able to find or order either photoflash capacitors or electrolythic ones that would be sutible for a shock wand. it you hooked several in paralell you could increase the voltage untill a fair amount of current would flow through the skin (more painful).

As for chargers you will probobly learn quickly that the camera flash inverters are slow even when pumped with alot more voltage and curent. I recomend an oscilator circuit that is more powerful than the camera's circuit and will drive a transformer at a high enough voltage to charge your caps. Alternatively you coulf build a voltage multiplyer out of capacitors and diodes for higher voltage apps where you can't find a small enough transformer. Voltage multipliers are kind of simple to build and when constructed properly can be very reliable and take in ac and conveniently output dc perfect for charging capacitors.

[pyromaniac_guy]

I have to most strenuously agree with pyro500 here. one should never get into the habit of touching charged caps. your 330v at 120uf contains 6.5j of energy at full charge. 3j discharged acrost your chest can cause arrythmia of the heart. granted a strong, healthy person can do this more safely than a 80 year old geriatric without their nitro pills, it is none the less foolish to unnecisarily put one's self at risk....

[xyz]

Ok, though the reason I like using camera chargers is that they stop charging when the cap is full and don't charge the cap till it heats up and ruptures from the pressure. I have measured that camera flash cap chargers put out about 300v so my cascade will have to have 6 stages to get 3v to around 200v and a 7th stage will make it 400v right? They double the voltage with each stage don't they? But I can't add 6.5 stages to get 300v, do I need to do anything special or will it end up about 300v anyway from resistance and the like?

Edit: Pyromaniac_guy, I have already explained that I DON'T have a habit of touching them and I did it on my hand and not across my chest, please read the whole topic before you post

<small>[ July 20, 2002, 03:41 AM: Message edited by: xyz ]</small>

[PYRO500]

no, sorry it dosen't quite work like that when you have multiple stages you multiply the voltage that you start with by the number of stages, for example I have 120V in, I put it through a 5 stage multiplier and I get 600V now charging your capacitors with a higher voltage than their max voltage is ok, but you do need to watch the voltage and switch it off before it covercharges. Also you have to be sure that it won't charge too fast either. what you could do is build an oscilator circuit like this one <a href="http://www.geocities.com/pyro2000us/untitled.jpg" target="_blank">http://www.geocities.com/pyro2000us/untitled.jpg</a> (copy and paste link into browser)

the part that's the oscilator is the part before the transformer(ignore the rest), the output of the transformer is what drives the voltage multiplier, when using a voltage multiplier in this case you would get the highest step up transformer you could find and then add that voltage multiplier directly to the output of the transformer (ignore the diode and the capacitors after the transformer there for something else and won't work with a voltage multiplier)
now assuming you got 100V out of the transformer (likely the circuit would give around 300V max) you would then add the appropriate amount of stages in your voltage multiplier to get 300V, in this case that'd be 3 stages. just a note here but the trnasformers won't always step up the voltage porportionally to their turns beacuse of the effect pulsing has on them, kep that in mind when looking at this circuit.

<small>[ July 20, 2002, 08:54 AM: Message edited by: PYRO500 ]</small>

[pyromaniac_guy]

xyz...
I DID read the whole post, and you said you deliberatly shocked yourself with more than 10 times the energy required to stop the heart, should you have fucked up in some way, and conducted hand to hand. My post was not ment to admonish you for doing this, you were warned once by someone else, if you hurt yourself doing anything similar, you win yourself a darwin award. The reason for my post was to warn (again) any other 14 yr old kids out there like yourself that what you did was quite foolish.

[xyz]

Obviously you didn't read it properly then. I said it was NOT me who shocked themself from arm to arm and that I did NOT deliberately shock myself with the 5 caps in parallel. It takes 30J to stop the heart and a photo flash cap is between 2J to 7J.

Pyro500, your page is down (damn geoshitties), it says that the owner needs to go to their help page. I have a small 240v to 9v step down transformer which I can use backwards (probably get a lot lower than 240v though) and then make a multiplier to get whatever power comes out of the transformer to around 300v.

<small>[ July 20, 2002, 07:26 PM: Message edited by: xyz ]</small>

[PYRO500]

My geocities page is not down, I said next to the link that you needed to cut and paste the link into your browser or it won't work. as for 30J being lethal, that's kink=d of like the LD50 on electric shocks during most circumstances, getting zapped by anything is a bad idea and people have been killed by alot less than 30J.

Anything that shocks you is potentially very dangerous and there is not really any way of determining how much shock will kill you untill all the circumstances are at their worst and not shocking youself from arm to arm is not a safe way of not shocking your heart.

<small>[ July 20, 2002, 09:31 PM: Message edited by: PYRO500 ]</small>

[xyz]

Yeah, I've kind of got the picture now, don't zap yourself.
Sorry about forgetting to cut and paste with geocities. What rate does that oscillator pulse things at?

[PYRO500]

That oscillator will work at difrent frequency's depending on the resistance in the circuit. That't the reason for the whine in camera flashes. The frequency the transformer is running at gets lower and lower untill the capacitors are charged and the circuit can't produce enough voltage to charge them any more.

<small>[ July 21, 2002, 04:17 PM: Message edited by: PYRO500 ]</small>

[xyz]

By "the resistance in the circuit", do you mean how charged the caps are or what the value of the resistor is?

If I was not using it to charge caps, how high would the frequency be and what could I do to make it higher?

[PYRO500]

by the resistance in the circuit I mean everything after the transformer, when the capacitors charge (in normal operation as a flash) the resistance rises as the capacitor(s) charge. it is hard to say how fast it would oscilate with a voltage miltiplier but it would charge up like a capacitor and give you DC from AC but at a high voltage.

[xyz]

If I used a 9 volt battery and some transistors that are designed for 9 volts, and then replaced the transformer with a relay, how many times a second would this circuit switch the relay?

[PYRO500]

you can't replace the transformer with a relay, that would not do anything worthwile, it would cause your voltage to stay the same as the input of the buzzing relay (why?) I can't really say the frequency you have to find out what it is using your components.

[xyz]

The purpose I was going to use it for was pulsing the power in a second circuit.

[PYRO500]

There are beter ways of pulsing a relay, or even better a transistor. for a relay an IC 555 timer would do fine.

[Boob Raider]

Fellow Zappers. U can get about 1kV or even more from (I have tried upto 1kV) photoflash chargers by connecting the outputs in series <img border="0" title="" alt="[Wink]" src="wink.gif" /> . I use the set up to operate a cold cathode florescent tube salvaged from a Photocopier. Speaking of photocopiers ... they have drum charging circuits (3"X1.5"X.75") capable of generating upto 12kV DC @ about 200 uA. I have one by TDK, it generates 7kV @ 600uA (24 VDC input) which I used for my table top N2 Laser and making O3. IF one can get there hands on enough photoflash caps that the voltage ratings would add upto 7kV with a safety margin of atleast 0.5kV then that would make one hell of a Pulsed Laser PSU (*wack*) I mean Shocker. :D
Dont try making HV caps at home with Al foil and any Dielectric and transformer oil. It aint worth it. Its like "fishing in a piss pond" (By Me). Success is very rare as far as that goes and those who do have to go through the bitching phase as the caps spray hot oil, smoke the garage, and waste a lot of money, effort and time :mad: . Air bubbles r to be blamed. So IF u r a very patient person and can work each and every air bubble out ... go for it, otherwise stick to reletavely low V caps in series. Actually e-Bay is a good place to fish for caps. I got a lot of em from there. 40kV Ceramite Doorknob caps etc. <img border="0" title="" alt="[Wink]" src="wink.gif" />
I had lots to say on this topic .... but I forgot. Ask me or I'll put it up when I get reminded by a post.

[PYRO500]

The problem with a bunch of caps in series is that the ESR is multiplied among them making the pulse that you normally had alot longer with less peak current.
As far as having a ton of photoflash capacitors goes, it's only worth it for small projects that don't require a very fast high current pulse.
For example I just bought a pulse cap that I have yet to calculate the esr for but typicly speaking thse capacitors are made to have low esr's for pulse duty. I am going to use this capacitor for a few experimental electronic weapons including a disk launcher that will launch an ancient 14 inch hard drive platter. I also am designing a plasma armature rail gun witch will possibly run with two more of these suckers if I can get 250$ anytime soon.

The capacitor is 4,200V and 298 UF witch is 2628J and considering 30 is considered lethal, this sucker will explode flesh like a firecracker in a tomatoe. Think back to NBK's idea of a super tazer that would do that, except this sucker is very huge and is sitting in an office chair in the pics and probobly weighs over 90 pounds. you have to cut and paste thes pics into your browser
<a href="http://www.geocities.com/pyro2000us/cap/cap1.jpg" target="_blank">http://www.geocities.com/pyro2000us/cap/cap1.jpg</a>
<a href="http://www.geocities.com/pyro2000us/cap/cap2.jpg" target="_blank">http://www.geocities.com/pyro2000us/cap/cap2.jpg</a>
<a href="http://www.geocities.com/pyro2000us/cap/cap3.jpg" target="_blank">http://www.geocities.com/pyro2000us/cap/cap3.jpg</a>
<a href="http://www.geocities.com/pyro2000us/cap/cap4.jpg" target="_blank">http://www.geocities.com/pyro2000us/cap/cap4.jpg</a>

[xyz]

Does anyone have a circuit diagram for a good circuit to pulse a relay with? There is one on powerlabs which turns a relay on and off 3000 times a second, I emailed Sam Barros asking for the diagram but did not get a reply.

[J]

You ought to be able to work out how to make a relay pulse itself! If you want a faster pulse rate than it can manage this way, you might as well use an SCR based circuit.

[xyz]

I am rather annoyed at myself for overlooking the obvious like that :mad: , It never occured to me that you could make a relay pulse itself but now that you say it I can see exactly how it would work, thanks.

[kanbayat]

ok..after reading all youre posts..I wonder if anyone has come up with a definitive wepon that can be made at radio shack with 50 bucks?
I know very little about electrical shit..so spill it guys.
personally if I had the same 50 bucks..i'd go to walmart..and no one would stop me..lol..but to the rest of us who know hardly any thing about what radio shack has to offer..what is the consensus of opinion here?..what type of lethal wepon can be made for self defense using 50 bucks at radio shack?..nico and I want to knoww

peace ppl