Harvesting Capacitors for Backyard Munitions 430
Diabolus writes "This is the tale of a man, a bunch of disposable cameras, and his techniques for harvesting lots of capacitors to build a gauss gun. Insane..." A basic capacitor tutorial is probably in order.
Anti-slashdotting.... (Score:5, Informative)
And I bet it still won't work....
Re:Anti-slashdotting.... (Score:2)
If he were properly motivated (and I'm sure he was), he could have the "slashdot friendly" webpage version prepared in under 5 minutes.
-Restil
That Sinking Feeling of Being Slashdotted... (Score:4, Funny)
It doesn't take very long to realize you're getting slashdotted if you're paying attention.
Yeah. First, you notice that kmail seems to be taking longer transferring mail than usual.
Then, you click on a webpage link, and your usually-quick DSL feels like dialup again.
The hard drive in your webserver is scratching so much, it's hard to think; it sounds like you're compiling a kernel and making a divx at the same time, but it's pages being served and visits being logged.
You fire up top and are greeted by a whole screen of httpd daemons and CGI.
Congrats, you're being Slashdotted.
It's actually kind of fun.
Re:Anti-slashdotting.... (Score:2, Insightful)
Re:Anti-slashdotting.... (Score:2, Interesting)
Speaking of capacitors... (Score:2, Interesting)
Re:Speaking of capacitors... (Score:3, Informative)
Re:Speaking of capacitors... (Score:2, Informative)
Re:Speaking of capacitors... (Score:4, Interesting)
But those little camera caps are chicken feed. Try on a 2700 Farad Capacitor [maxwell.com] on for size!
Re:Speaking of capacitors... (Score:2)
2.5 V
Re:Speaking of capacitors... (Score:3, Informative)
How big a spark you get is a function of the latter. How long that spark might last is a function of the former. The voltage you get out of a capacitor is always the voltage you put in (minus resistance losses). Capacitors are voltage rated because a high enough voltage will break down the dielectric and spark inside the capcitor. Some chemical capacitors, like many electrolytic capacitors, will break down with a rewarding explosion. Some, like ceramics, will maybe make a bit of a "pop" and then either become shorts or open.
I've probably made things clear as mud...
Re:Speaking of capacitors... (Score:2)
Tecate Industries [tecategroup.com] manufacture the PB series. A 4 Farad capacitor measuring 24x18x4.8mm (approx 1x3/4x1/5 inches), and a 10F capacitor measuring 24x33x4.8mm. 2.5VDC, 1A.
Cooper Electronic Technologies have the B series [cooperet.com] which offer 1 to 50F capacitance and are capable of 35A at 2.5V. They are the size of a AA battery.
Perhaps next time you should make an effort to check things out before "calling the bluff"?
IANAL, but.. (Score:2, Insightful)
Re:IANAL, but.. (Score:2, Insightful)
Re:IANAL, but.. (Score:2)
Re:IANAL... if recall (Score:3, Informative)
According to the ATF it is not illegal to make your own gun provided it is not a semi automatic and the person is not making it for sale and the person is allowed to possess a firearm.
A7) Does the GCA prohibit anyone from making a handgun, shotgun or rifle? [treas.gov]
With certain exceptions a firearm may be made by a nonlicensee provided it is not for sale and the maker is not prohibited from possessing firearms. However, a person is prohibited from making a semiautomatic assault weapon or assembling a nonsporting semiautomatic rifle or nonsporting shotgun from imported parts. In addition, the making of an NFA firearm requires a tax payment and approval by ATF. An application to make a machinegun will not be approved unless documentation is submitted showing that the firearm is being made for a federal or state agency. [18 U. S. C. 922( o), (r), (v), and 923, 27 CFR 178.39, 178.40, 178.41 and
None of which is actually relevant... (Score:2)
None of which is actually relevant, seeing as this is not a firearm. There may be applicable laws (I'm sure there are, but probably not any) but the stuff you are referencing simply doesn't apply to gauss guns anymore than it does a homemade crossbow or staff-sling (either of which would probably be comparable for destructive capability with this guys gauss gun, if he ever gets it working, btw.)
I think mine is legal then (Score:2)
Legal and profitable (Score:2)
Re:IANAL, but.. (Score:3, Insightful)
1. Adelaide is not yet in the U.S.
2. I can't see how his building the gun is reasonably related to the maintainance of a state militia. So the 2nd amendment wouldn't apply anyway.
Re:IANAL, but.. (Score:2, Informative)
What's the stance in the U.S. on privately owned nuclear ICBM's?
As long as they are non-functional as weapons, yes. You may NOT own a functional WMD.
Many private citizen vet organizations own tanks, old rocket launchers, etc. There are a number of non-weapons capable fighter aircraft in private hands, all the way from WWI biplanes to a guy restoring an early model F-16. And I believe there is a privately owned MiG-29.
"Demilitarize" it, and you're ok. Basically, the BATF says anything over
This is "Importation of arms, ammunition, and implements of war" [treas.gov], but the same rules probably hold for domestic products.
Re:IANAL, but.. (Score:2, Informative)
Re:IANAL, but.. (Score:3, Informative)
2) "Militia" meant simply all male citizens of age and condition to be fit for military service. It wasn't necessary to be in any sort of organization, if you could potentially fight you were a member of the unorganized militia. "Well regulated", in 18th century military terms, meant "well equipped".
So the "militia" clause expressed a hope (not a law) that the citizenry would arm themselves suitably for military operations, just in case it became necessary to call on them. (And many indian wars, as well as the successful defense of New Orleans against British regulars in the War of 1812, were conducted primarily by men who joined up for just a few months.) The binding main clause says simply that the federal government should not interfere with individuals obtaining and owning "arms".
However, the US Supreme Court has always dodged cases that would require directly defining the limits (if any) on "the right to bear arms". It came closest in "Miller vs. US", where it decided that there is no right to own a sawed-off shotgun - confusingly, this decision went a ways down the road of misinterpreting the first clause, but then finally decided that the weapon in question was not covered since the military doesn't use shotguns. By the same logic, "Saturday night specials" (the cheapest, lowest quality handguns) wouldn't qualify either, because real military forces prefer weapons that don't blow up in your hand when properly used. The real problem at this point is that this reasoning seems to imply that you should have the right to buy and keep in your home a standard infantry weapon - nowadays, that's an assault rifle that can empty a 30 round clip in under 3 seconds. But we have laws not only forbidding these, but forbidding anything that even looks like them...
By the way, in Switzerland every able-bodied man is a member of the military reserve, and the government GIVES him a military weapon to take home. And the Swiss don't use them to massacre their neighbors. Is it because the Swiss are that much better behaved than Americans, or because they know the neighbors are equally well armed???
Re:IANAL, but.. (Score:2)
Re:the Swiss are MUCH better behaved than American (Score:2)
A slight exaggeration, I'm sure, but point taken. There must be _some_ Swiss criminals, but the worst thing I've ever heard a Swiss accused of was a sort of bureaucratic crime - just keeping any money deposited by (probably dead) German jews before WWII in Swiss banks unless someone could actually prove he was the heir...
I do wonder though, how much of their good behavior comes from every man going through boot camp (for centuries), how much from the knowledge that your neighbors have as much firepower as a regular infantryman (although I've heard that a Swiss who uses his military weapon without authorization goes to prison longer than the average American murderer), and how much from other factors...
Re:IANAL, but.. (Score:2)
I agree that anti-gun people using Miller to defend their position is stupid, since the Court basically said that the 2nd Ammendment *only* protects the right to own military grade hardware.
Re:IANAL, but.. (Score:2)
Ye gads! How do you fire that thing without breaking your wrist? Or do you only fire it when the alternative may be worse than a broken wrist? (For those that didn't follow monkeydo's link, it's a pistol with a 6 inch shotgun barrel.)
IIRC, in those laws concerning the minimum barrel length, part of the definition of rifle or shotgun is that there be a shoulder rest - whether permanent like most long guns, or folding or detachable. I don't see any place to attach a butt, so that weapon would probably be classed as a handgun of monstrous caliber.
Didn't the Hague and Geneva conventions ban shotguns from military use? Certainly in 1904 or thereabouts when the first of these conventions started, the military wasn't using shotguns. The big argument was about dum-dum bullets, which were pretty useful in colonial wars against people like the Zulus or Moros. Anyway, a shotgun (long or short) makes a good military weapon only in very special circumstances - but put troops in those circumstances long enough and they'll obtain a shotgun whether it's allowed or not. (And since Vietnam was officially a "police action" no matter how much it seemed like a war, and cops do use shotguns...)
Re:IANAL, but.. (Score:2)
I agree, the second should be re-written - not because it's meaning is all that foggy, but because there is an underlying right that the Founding Fathers never imagined any government in the English tradition would ever infringe - but now it's being infringed widely. E.g., the old farmer in the UK who is now doing 10 years for defending himself against burglars. He was repeatedly burglarized - and I suspect beaten, that being SOP by many UK burglars nowadays - until he illegally obtained a shotgun and shot the next bunch. In Australia, home invasions have skyrocketed since the gov't confiscated honest peoples' guns, and in some US states, you can keep a long gun in your house but it's almost impossible to use it in self-defense without facing both criminal charges and civil suits for abusing the poor criminals. So if I could rewrite the Bill of Rights now, the very first article would start:
Re:IANAL, but.. (Score:2)
some other cool things to do w/ capacitors (Score:5, Interesting)
As my advisor said (Score:4, Funny)
"Any diode can be light-emitting
Re:As my advisor said (Score:2)
Flux? (Score:5, Funny)
Re:Flux? (Score:5, Funny)
Re:Flux? (Score:2, Funny)
Re:Flux? (Score:5, Funny)
Dude, make one up quickly in the back room and sell it to them for 300 bucks. When they come back complaining, ask them if they have a degree in nuclear physics. When they say, "no", then politely take it back, minus a 95 dollar restocking and time-diffusion recharge fee, which you pocket.
Re:Flux? (Score:2)
Re:Flux? (Score:2)
No, you'll just have to travel at 60 minutes/hour like the rest of us.
Besides, I hear society is going to collapse when the unix time type runs out in 2037 anyway....
Re:Flux? (Score:2, Funny)
No it will be far worse than that, time_t will overflow and go back to 0 and society will instantaneously jump back 2^32 seconds - To 1970!
Get your bell bottoms out people...
Re:Flux? (Score:2)
Oh my god, not another crappy seventies revival...
Re:Flux? (Score:2)
Dammit, I thought it said "Floss Capacitors". Now the Novicane is starting to wear off, and it smarts.
cheap yes, but practical? (Score:2, Interesting)
Seems like a lot of work for a huge mess of solder and wires for what would amount to a fraction of what a single car-audio capacitor would put out.
Am I missing something, or is his time worth nothing?
Karma: Excellent
WTF?
Re:cheap yes, but practical? (Score:5, Informative)
Yes, you are missing something.
Car audio capacitor: 16-20 volts @
Camera flash capacitor: 330 volts @ 120 uF.
Now lets see, using the formula E = 1/2 * U^2 * C [epanorama.net], how many joules are in each capacitor.
Car audio capacitor: E = 20 Joules
Flash capacitor: E = 6.534 Joules
Car Cap: $40 or $2 per joule.
Disposable camera: $5 or $0.76 per joule.
Camera caps are far cheaper, and this guy got them for free.
Karma: Excellent (Score:2)
Mine too... I wonder what the new ranks may be; CmdrTaco, Excellent, Great, Good, Average, Below-Average, Loser, Whiner, Troll, goatse.cx and Bill Gates? :-)
Re:cheap yes, but practical? (Score:5, Informative)
For his purposes he requires an actual high capacity, high discharge rate capacitor, not an easy thing to create.
The challenge is having a VERY low ESR (effective series resistance), as well as a low inductance, and using a massive number of parallel capacitors is certainly one of the only economical ways of doing this. a LOT of care is also needed in how they are connected up to keep the inductance down.
You can, for example, by multi-farad 'supercaps', but these have charge/discharge rates in the milliamps and are used for memory backup and other purposes, you can also get kilovolt rated caps with very low capacitance, but it is very hard to get medium voltage very low ESR high energy caps, primarily because they are lethal. They are used in radar installations and a few other high energy 'toys'.
Re:Rubbish huh? (flamebait) (Score:5, Informative)
The real answers arent all that profitable, nor are they very cool, so we sell you big caps, and your friends drool with envy at your new equipment while you pretend to hear a big difference in the sound. The same principle drives the music/clothing/other industries... 'the dumbest buy the mostest'
Have you ever played with a car amp that needs 1000 watts?
No, and neither have you. 1K watts is about 1.5 HORSEPOWER. In recent years, many manufacturers of car audio equipment have been competing for your money by putting really large numbers on the cases of thier devices just because it makes kids buy them. Take the average radio.. a good one claims to do 40 watts per channel, on a 12 volt powersupply and a 4 ohm load, the maximum possible output wattage is 36.. and thats assuming a 100% efficient amplifier (which doesnt exist)
Re:Rubbish huh? or The Theory of Car Audio Amps (Score:2, Informative)
Well, you are right about the 36 watts. But many car audio amplifiers use inverters these days, allowing them to increase the voltage manyfold. Thus they may have fifty plus volts to play with (no pun intended) and can output many watts... but usually these are not RMS (continuous) watts, but PMPO or some crap like that.
Re:40 Watts (Score:3, Informative)
The radio you describe is the same bridge output amplifier that a few years ago was rated at 12.5 watts per channel, or 25 watts for 2 channel or 50 watts for 4 channel. It's the same voltage into the same load. Nothing has changed but the numbers.
Because people tend to by things by comparing the fancy numbers on a spec sheet, lots creative writing has been done to seprate fools from their money.
#1 Rate peak power instead of RMS average watts.
Explaination; Music is not DC heating power. If you take the maximum DC voltage and figure the power based on load resistance, you can get a high number. In the example given, 40 watts was tossed out. It was pointed out that that number refuted with a supply of 12 volts. It wasn't figured at 12 volts. The charging system provides about 14 or more volts. Redo the math with this number.
An audio waveform is not a sine wave. The peak possible voltage is not provided to the speakers 100% of the time. In the '70's some good stuff was rated at RMS power at a specified distortion level. In the above case, 40 watts is only possible with the engine running and the speaker voltage never leaving peak values. In short a very distorted square wave output. Not pleasant music in my book. A 6 Watt RMS rated amplifer at 0.1 THD is a much more powerful amplifier. My favorite amplifier is rated 25 watts RMS per channel at 0.04% THD into a 4 ohm load. Some amplifiers are rated to provide their rated output only a very low speaker impedances. 2 and one ohm are common. Almost half the power rating for these as they can not provide the voltage needed to properly drive rated power into a 4 ohm speaker. Needless to say, that rating will misslead most newbies in the audio field. The don't understand why my 50 watt amplifier uses 8 AWG wire with a 20 amp fuse. They are also supprised when I connect a scope and show it provides more unclipped peak to peak voltage to the 4 ohm speaker than most amplifiers rated 200 watts. Yes the honestly rated 25 watt amplifer is a bigger and higher power amp. That rating is not a peak power rating. Learn to compare apples with apples. Is the spec peak or RMS? Is that rated into 4 ohm, 2 ohm, 1 ohm? Is that rating guaranteed at 11 volt supply, or does the amp need to be under the hood getting 14 volts direct with no power distribution system to provide voltage loss due to resistance and distance? If you have a 200 Watt RMS into 4 ohms rated amplifier, I'll be looking for serious hearing protection! The car audio market is "let the buyer beware". The specs on paper are deliberately missleading. Borrow a scope and a dummy load. Find out how much Peak to Peak voltage the amplifier will deliver before before clipping occures. Don't buy anything that will not put out at least 40 volts for a small amp and 80 volts for the super thumpers. Half these values for brige mode amps. I have seen stuff rated at 120 watts that are powered by an 8 amp fuse. 12 X 8 is only 96 DC watts in at the point the fuse will blow. (commenly spouted spec for cheap underdash EQ-boosters) Some power is lost to heat in the audio conversion from DC. How much is left for each speaker? How are they expecting to get 120 watts out with only 96 watts maximum in? That rating is not RMS average music power! There is some honest stuff out there. However bring your pocketbook. It isn't cheap!
Now onto the function of caps. Music has it's peaks and valleys. The resistance of the electrical distribution system is finite. It includes the wire, battery internal resistance and alternator internal resistance. Current draw over a finite resitance provides a voltage drop over the resistance. This is well defined in ohm's law. The current drawn by an amplifier is not constant. It varies. Simply the more the current draw over a fixed resistance the more the voltage drop. Because of this the voltage drop varies as the current drawn varies. The wiring can have it's resistance reduced by using bigger wire, battery resistance can be reduced by adding more batteries (and placing one close to the amp to shorten the wire from battery and amp).
To provide the maximum voltage to the amplifier at a music peak, the loss in DC voltage at the peak current draw can be acheived by providing the peak current from a local capicitor instead of through a long wire to the trunk. A big capacitor can provide the short duration high current the amplifier demands on a music peak, preventing the high current peak on the DC distribution system and it's associated peak voltage drop. A good scope will tell you in short order if the money is worth it. Watch the voltage drops on high power music at the amplifier with and without the cap. Saving a 1/2 volt peak drop may make a diffrence in a competition, but most people won't need it. Don't even consider adding a cap if your music peaks drop the supply voltage at the amplifier less than 1/4 volt. You don't need it.
Re:cheap yes, but practical? (Score:4, Informative)
Re:cheap yes, but practical? (Score:2)
In unison, "Nothing"... (Score:5, Funny)
Be careful if you try this; those capacitors hold a fair amount of charge.
My brothers and I played with some of them in the kitchen at a family gathering a few years back. One of them is in the biz, and had more used, disposable cameras then he knew what to do with. We were bored and trying to rig up something ad-hoc (as I recall, we were using whatever we could find in the kitchen--rubber bands, tupperware, etc.) Our wives were in the dining room with the everyone else, and we weren't being very structured about it.
Things were going fairly well until we accidentally shorted something. There was a loud bang, a flash, and one of us jumped back, knocking over a pile of pie tins.
All conversation in the dining room stopped, and after a moment our mother's voice called calmly: "What are you boys doing in there?"
Without missing a beat we all replied, in unison, "Nothing!"
It was like old times.
-- MarkusQ
Re:In unison, "Nothing"... (Score:2)
Are you boys cooking in there?
No, Mom.
Are you boys building an interocitor in there?
No, Mom.
Bonus points to anyone who knows the source
Re:In unison, "Nothing"... (Score:2)
. .
Terrorist threat from cameras (Score:5, Funny)
Imagine the memo to baggage scanning technicians:
"WARNING: Any passengers attempting to take large numbers of disposable cameras on board any flight is a terrorist. These cameras can be used as a weapon by assembling a gauss gun from their parts. Call your appropriate superviser IMMEDIATELY if you have any suspicions"
Re:Terrorist threat from cameras (Score:5, Funny)
Imagine all the things they would start banning if McGyvor worked for Al Quieda.
some comments (Score:3, Interesting)
1) you can buy capacitors for less trouble. true, large 330V caps does cost money and he is getting this for next to nothing, but i think it's better to shell out a couple hundred bux for components for that gauss gun instead of subjecting myself to hours upon hours of de-soldering and discharging capacitors and getting flashed.
2) if you *really wanted*, you can also pull caps off old TVs, or any CRT in general; and they can go up to 20kV! heck man... for self-mutilation fun, doesn't 20kV sound better than 0.3kV? (erm... becareful when you do this. those caps can hold charge for like 20 years)
3) you can achieve the same with a large (i mean gigantic) low voltage capacitor, which would actually handle more current anyhow. (car) Audiophiles probabbly know what i am talking about. there are 10-15V capacitors for your huge woofers that carry up to 10 FARADS. nope you did not read this wrong... 10F, no m,u,n,p; straight up 10F. if you wanted the high voltage, either build yourself a HV transformer (easy) or salvage one from a junkyard (you know, ignition system).
but otherwise, rock on. i would like to see the 5kJ gauss gun in action someday, preferably tested on a furby or something
I have a *neat* capacitor (Score:2)
Does anyone know anything about things like this? Is it worth anything?
Fun With Capacitors (Score:3, Interesting)
Re:Fun With Capacitors (Score:2)
Horrible Story Time (Score:5, Funny)
Anyways, I was responsible for 4 complete goobers and one gorgeous blonde (who really dosent have anyhting to with the story, but I just want to mention her), which was not an enviable task. They got bored on the plane to hawaii and took apart their disposable camera ... well low and behold they figured out about the only thing you can do with a broken disposable camera is shock shit or get shocked. After some dumb luck (getting shocked in the first place) and some trial and error, they figure out if you touched these leads and pressed that button youd get shocked ... so the next step was to walk around the plane getting people to hold the leads so they could shock them (someday Id like to know why you would hold two leads a 14 year old asked you to).
So one afternoon our scheduled activity was to hang out in this park because thats damn cheap :) and well now you have to know about the director ... he was this big fat, raunchy, disgusting fat fuck who happened to be one of the best directors in the nation, and he had this even fatter and even rauncher wife their two skinny (but soon to be fat kids). The wife was horrible annoying and the kids were even worse, the whole band was sick of them. Meanwhile in the park, the band was getting pretty restless, shocking eachother with cameras actually became entertainment :) So these guys I am responsible for are shocking eathother, Im hitting on the blonde (amy hays if you're out there... ;-) ), and oie of the directors sons walks up and he says "Hey what are you guys doing?" (the kid couldn't have been more then 6 or 7) One of the worst jerkoffs in my section gets this HUGE grin on his face and he says, "I'll show you. you touch this and this, and then press this button" Meanwhile I look over and see whats going on, as Im screaming "nooooooooooooooooooooo!!" in slow motion like the matrix, the kid shocks the crap out of himself and I swear he almost pissed his pants as he took off running. We never got in trouble so I dont suppose he told his father :) but we were paranoid the whole rest of the trip.
on an unrelated topic, couldn't this guy just buy a couple 1 farad capacitors? Those are pretty popular with car audio buffs, they run maybe between 100 - 200$ a piece, I think that would be so much easier then getting UV burns like this guy is describing :D
Re:Horrible Story Time (Score:2)
Of course, now I am not a stupid dweeb anymore. My therapist assures me of that all the time.
Re:Horrible Story Time (Score:2)
Oh man, if I had a nickel for every wacky tenor sax story I have.... woooo-eeeeee.
So this one time, at band camp... (Score:2)
OK, so how comes I'm the first person to write that?
Marx Generator Story (Score:2, Interesting)
P.S.: Word to the wise: just the task of putting a load across the output terminals can set one of these things off. I was moving one of the terminals with a metal screwdriver and I accidently touched the other contact with my other hand. To this day I do not know how I managed to survive that one.
a reply to some comments (Score:5, Informative)
First of all, there are no pictures of a gauss gun, because it doesn't exist yet. I have the parts for an inverter to charge it, but have not yet assembled it. Not having had much experience with switch mode power supplies, I'm just hoping it doesn't burn down.
For someone else's (working) effort, check out powerlabs.org [powerlabs.org]
As to those who think car capacitors, etc might be better, they have a very low voltage rating (eg 15V). E=0.5*C*V^2, so even with a farad the energy isn't that great. Secondly, they are made from *thin* foil and have crappy current ratings, not much good for generating 10kA for 1ms. These are photoflash-rated caps, intended for 1ms discharge times - thick foil, good dielectric and some actual quality control.
Lastly, the capacitors will have to discharge through an inductor, even if it is only a couple of turns. Lack of voltage means the current rise is too slow (dI/dt = V/L) and so a low voltage, high capacitance bank will not discharge fast enough. Slow discharge means the ring has moved away before it receives much energy.
I'm also missing large silicon devices to actually discharge the thing. SCRs that can handle 10 or 20kA are not common and seem to cost many hundred of dollars. If anyone's got a spare one, please tell me! Otherwise I will have to make do with lots of smaller devices from surplus shops and build it multi-stage with messy triggering.
As for energy, consider 0.5*m*V^2. Given about 3 to 5kJ and about 2g of mass, you figure it out. It will be lucky to get 1% efficiency, but still. If it works well, I might have to look into firearms licensing. Big deal.
To those who say "you're a dickhead, that's lame", well, fair enough. Its not for everyone, and this page wasn't put up for the express of having it critiqued by /. bottom-feeders. I guess you could say "that's just sad", but if you're not an eleceng then you're not going to get what's interesting about this stuff.
Re:a reply to some comments (Score:5, Informative)
If you want some high-voltage capacitors, some of the electronic junk shops should still have them from the days of valve electronics, when they were exceedingly common. I recall as a teenager connecting up something like 3,000 microfarads at 600V and charging this up to 380VDC from a 230VAC mains supply.
This, when discharged, produced especially satisfying results when the target was a small piece of magnesium ribbon, placed under water in a plastic cup.
The high current vaporised the magnesium which explosively reacted with the water to destroy the cup in a most satisfying way. I imagine that aluminium wire would also work quite well.
Alas, the innocent experiments of youth would probably today have me rounded up as a terrorist, since amongst other things we also made gunpowder and nitroglycerin (which we never detonated because we were too scared to!).
Anyone planning on fooling with high voltages and high energies should be aware that even modest voltage and energy levels can cause fatal heart arhythmia if the shock coincides with a vulnerable point in the heart's electrical cycle. I would strongly recommend that you wear insulating gloves while working on any circuitry and be exceedingly careful. Also be aware that capacitors which have been abruptly discharged can then spontaneously recharge without being reconnected to a power source. This could cause a potentially fatal shock, so you should always connect the capacitor terminals together when working on any circuitry.
Re:a reply to some comments (Score:2)
You know that was really stupid, right?
C//
Re:a reply to some comments (Score:2)
For all the effort you're going through, I'm surprised you're only planning on a single-stage. I looked into gauss guns a few months ago and came to the conclusion that multi-stage is definately the way to go. Triggering isn't that bad, just a few pulsed LEDs and photo-receptors along the barrel. I gave up when I realized I couldn't afford the SCRs and capacitors (the lingering feeling that I was going to kill myself probably didn't help either). Good luck.
Completed gauss gun projects (Score:5, Informative)
Pop a Cap in someone (Score:2)
Here's a new weapon idea!
How about building a device that charges these small flash caps and then fires them out as projectiles. Anyone unfortunate enough to get hit with the contacts gets "knocked on their ass" as many experimenters have discovered.
I'm gonna pop a 0.22 Farad cap in your ass sucka!
Gauss Guns (Score:2, Insightful)
Yes, I did just pilfer these sites from Google, but didn't see any other references linked so far, soooo.....
story from my dad (Score:5, Funny)
When my dad had her in his group covering electricity she was no help at all. One day my dad brought in some large capacitors for a class project. He got to class a little early that day, on the counter next to his table he noticed the hand crank generator, a spool of wire, a slinky, and the rivits holding the wood plank seat to the metal legs of the annoying girls chair.
placing the slinky on her side if the table, running wires from the legs of the chair & slinky to the capacitor then chargeing the hell out of the capacitor with the generator he sat and waited.
long story short, she sat down, grabed slinky, screamed, got my dad sent to the priest office (it was a Catholic school), dad spent rest of week cleaning church after school, dad got extra credit for "demonstrating practical uses of electricity"
Here's how to build o (Score:4, Informative)
Here's a much more powerful Multi Staged Gauss Rifle [powerlabs.org] for anyone interested as well.
Capacitors can be fun.. (Score:2)
I used to charge up small capacitors and place the leads between the pages in my books. When walking the halls between classes, I would pull them out and shock people. Our halls were pretty crowded so you could be very covert. We also used the capacitor tester as a wimp detetector. Five or so people would hold hands with the end people each getting one of the charging leads. Another person would slowly turn up the voltage until someone wimped out and let go. Normally that person also got a little extra from the resulting arc.
A story from High School... (Score:2, Funny)
Anyway, there was this one sophmore who hung around with us, who was always trying to immitate our projects (usually badly). He was ok, I guess, and it was usually funny to listen to his recent mistakes/problems (like accidently land-mining his room in the middle of the night with exploding paper strips.)
The hallway at our school were long, with lots of glass, and metal rails running along at about waist height. Usually, all the students would lean against the rails before class.
Well, one guy in our group had torn apart a disposible lighter and had gotten the electronic igniter out of it. He would touch the wire to the railing, and when he pushed the button, everyone touching the rail would get a shock (very minor shock). It was irritating and fun!
Well, this sophmore decided to "one-up" us, and managed to get hold of the igniter from a gas stove. The thing was about 10 times as big as the small igniter, and produced a nice, fat spark when pressed.
IIRC, he managed to shock himself, while the rest of us stood around laughing. I think he finally gave up on trying to shock anyone with that.
-Ed
docbrown.net [docbrown.net]
Graphic Design, Web Design, Role-Playing Games...all the good stuff
THIS, dudes, is how you build the EMP Weapon (Score:3, Interesting)
Indeed, I can zap all the control circuits in a modern fly-by-wire jumbo aircraft and make it do a ballistic imitation of a large brick. If I time things right, I can bring a fully fueled jet down right in the middle of San Francisco.
Can you say "9/11?" Sure you can. So here we are, nine months along, and those who are supposed to protect us are as clueless as ever.
I could create total electronic chaos and another 9/11 with a homemade, explosively pumped, flux compression generator, and I can do it with data I found on the Internet, including some very helpful stuff from the Los Alamos nuclear lab web site.
We're talking here about an electromagnetic pulse (EMP) weapon, the neutron bomb of electronic circuits. A garage EMP bomb is amazingly easy to build, especially with a 15-minute Google search.
Undoubtedly you have read about the EMP weapons we used in the Gulf War and Yugoslavia to take out air defense electronics. What you may not have read about is a 1995 incident when Chechnyan rebels used one to fry security circuits in 1995 to gain access to a Soviet facility.
Yeah, I've tried for months now to get anyone in power to care. Local law enforcement said it was not their table and to call the Feds. The FBI agent on duty in San Francisco was totally clueless
I used to work for U.S. Senator Thad Cochran. So I called one of the staffers I knew, and she referred me to the White House Liaison for Home Security. No call back there, either.
But maybe an EMP weapon sounds too much like anti-gravity boots and close encounters with Airstream trailer communities in the Mojave and that's why nobody returns calls and nothing gets done.
But realize this: the NATO document mentions the use of an EMP weapon by Chechnyan rebels. Al-Qaida includes many Chechnyans among the hard-core fighters, thus the usefulness of EMP weapons has surely been transferred to the bad guys still out there looking for an opportunity to make another big splash.
So, I couldn't just let the non-responses from the FBI and Homeland Defense be the end of the matter. With a little more digging on the Web, I located a DOE phone directory last week and called the folks who are head of security for the national nuclear labs. I actually got a call back and forwarded the information (below) via e-mail. I got a form e-mail reply, but the Los Alamos page (http://www.lanl.gov/dirac/) is still up there.
Why is the Los Alamos page important? Because it gives me a good look at an actual physical configuration of a real bomb that works. Taken together with the other web pages, it gives me an excellent chance to build a bomb that works.
Perhaps having the data out there for anyone is a victory for open info on the net, but then how easy DO we want to make it for terrorists? Where is the line between the free flow of information and discussion and giving folks easy access on how to build weapons?
EMAIL TO NATIONAL LABS SECURITY FOLLOWS
>Date: Mon, 04 Mar 2002 11:15:26 -0800
>To: marc.hollander@nnsa.doe.gov
>From: Lewis Perdue
>Subject: links
>
>Very nice chatting with you. Below are the major links I mentioned.
>
>Some detailed background on the threat can be found in a NATO Parliamentary Assembly report at:
>
>http://www.nato-pa.int/publications/comr
>
>I quoted from this report at the end of this e-mail. But particularly relevant is the following from that NATO report:
>
>"38.The possibility of terrorists using EMP weapons has been raising alarm for at least a decade among defence analysts. According to Winn Schwartau, an information warfare specialist, rudimentary EMP devices have been assembled by US Department of Defense consultants within two weeks at the cost of $500. Such devices, capable of disrupting computers, medical equipment and cars, could be placed in a van or even reduced to fit into a suitcase. Criminal organisations in Russia have been accused of using EMP devices to bypass alarm systems. According to the Russian Armed Forces, Chechen rebels might have used similar technology to disrupt Russian electronic communication equipment."
>
>As I mentioned to you, I can describe how such a device could be used to cause another 9/11-type disaster.
>
>links:
>
>THIS IS A KEY ONE: http://www.infowar.com/mil_c4i/mil_c4i8.html-ssi
>THE FOLLOWING may seem harmless, but the principles for forming metal, apply directly to an EMP weapon, both in learning how to acquire the capacitors for the construction, and because the electromagnetic pulse formation is very nearly the same.
>
>http://www.mse.eng.ohio-state.edu/~dae
>
>THE FOLLOWING ARE SOURCES FOR THE PULSE POWER CAPACITORS NEEDED
>
>http://www.nwl.com/
>http://www.a
>http://wwwcsif.cs.ucdavis.edu/~wiley
>
>
>YOU'LL WANT TO FOLLOW LINKS FROM THIS PAGE:
>http://er6s1.eng.ohio-state.edu/~daehn/hy
>
>SOME OF THOSE LINKS INCLUDE:
>
>Manufacturers of Pulse Power Equipment
> Maxwell-Magneform
> IAP Research
> Elmag, Inc.
> Pulsar Technologies (welding / crimping)
> Manget-Physik (German Mfr. of Electromagnetic Forming Hardware & MagnetoPulS® Technology)
> Kharkov Polytechnic University, Ukraine (research and equipment)
>
>Other sites related to high velocity deformation and/or hardware
>Pulse Power Equipment
> Richardson Electric (ingitrons)
> Maxwell Technologies
> Pulsed Power Technologies, Inc.
> Pulse Power Switching Overview
> Fantastically Dangerous Cap. Bank Experiments
> Aerovox Corp. (capacitor mfgr. )
> Darrah Electronics (solid state switching)
> Contents of IEEE Pulsed Power Conferences
>
>High Velocity Forming and Pulse Power Applications
> EMF Industries, Inc. (assembly with EMF is highlighted)
> Sparktec Environ mental Corp (uses sparks for water purification)
> Dana Corporation Develops Improved Magnetic -Pulse Process
> Electroimpact Home Page (mfr. of electromagnetic dent removers etc.)
> CONTENTS PAGE - RESEARCH AT SSAU (1997) (Russian welding, etc.)
> Simple Analysis from J. Krauss Electromagnetics Book
> Robert Hahn at IWF, Technical Univ. of Berlin (in German)
>
>IF YOU WERE DESPERATE FOR C-4 or Semtex for your EMP device, and didn't have a source for the ready-made stuff, you could try here:
>
>http://www.phreak.org/archives/The_Hac
>http://www.strange-days.d
>
>FINALLY
>
>New material continues to be posted on the Web. If you do a search for "flux compression generator" you will find more listings than just the ones above.
>
>
>NATO Parliamentary Assembly
>http://www.nato-pa.int/publications/comrep/200
>
>37.Yet another threat seems more imminent. As Ehlers indicated in his report, computer systems and all electronic devices can be seriously damaged by weapons producing electro-magnetic pulses (EMP). High Power Microwaves (HPM) or EMP bombs and High Energy Radio Frequency (HERF) guns can radiate intense pulses of electro-magnetic energy capable of severely damaging computers, radar and all electronic equipment. They can even destroy circuits, microprocessors and other components. These weapons are well-known in Russia, where extensive studies were conducted during the Cold War. The US Air Force used EMP and HERF weapons successfully in 1991 against Iraqi radar installations, and in 1999 against Yugoslav electronic infrastructure.
>
>38.The possibility of terrorists using EMP weapons has been raising alarm for at least a decade among defence analysts. According to Winn Schwartau, an information warfare specialist, rudimentary EMP devices have been assembled by US Department of Defense consultants within two weeks at the cost of $500.
Such devices, capable of disrupting computers, medical equipment and cars, could be placed in a van or even reduced to fit into a suitcase. Criminal organisations in Russia have been accused of using EMP devices to bypass alarm systems. According to the Russian Armed Forces, Chechen rebels might have used similar technology to disrupt Russian electronic communication equipment.
>
> 39.In his book Cybershock, Schwartau considers some possible effects of a well-orchestrated EMP attack upon Western infrastructure:
>
> Wall Street or other banking systems can be attacked, causing repetitive failures resulting in financial losses. Also past records can be wiped out by onslaughts of electromagnetic pulses; aircraft avionics and guidance systems can be overloaded by targeted HERF, causing potentially deadly conditions; medical equipment can fail under the attack of intense energy spikes, putting human lives in danger; communication nodes can be burned out by intense microwave radiation; municipal emergency services can be made inoperable by debilitating wide-band microwave jamming; power lines and transformers may serve as efficient conductors to transmit huge current to victim businesses and sub-stations, causing regional black-outs.
>
>40.The ability to build EMP weapons is apparently quite widespread, yet there are no international controls over the import and export of the related technologies. Defensive techniques, although in some cases expensive, have been partially deployed in the public sector (especially to protect military assets), but remain extremely rare in the private sector.
Electrical Engineers vs. Mechanical Engineers (Score:3, Interesting)
Mechanical Engineers build can crushers with moving parts [glowingplate.com].
Electrical Engineers build can crushers with no moving parts [tripod.com].
However, whatever the discipline, no mad science lab is complete without a Furby Testing Program [voltnet.com].
Re:Electrical Engineers vs. Mechanical Engineers (Score:2)
20kA through 12 gauge wire without it instantly vapourizing? I don't think so...
Picoseconds. Believe it, I've seen magnetic can crushers fire. (I've also been allowed to play at length with a tesla coil excited by a junked 50kW AM radio transmitter, but that's another story.)
Calculate how many amps are flowing through that photoflash in the disposable camera in your hand when you press the button. The wiring is usually like 26 gauge, and it doesn't melt in that time.
Re:and chemical engineers (Score:2)
Fill a can with a little bit of water and set it over a flame until the water begins to boil. At this point most of the air has left the can and been replaced with water vapor. The can will not implode yet,
Of course! Chemical engineers build their own can crushers.
Do any of the other disciplines do this, that we can think of? Aerospace? Civil? Structural? Software?
Re:umm (Score:2)
There you will learn that instead of buying tons of cameras, he is friends with a local store that would rather give them away/pitch them than go through the hassle of sending them back to Kodak for reuse.
Forget Photoflash Caps - Get oil-filled HV Caps (Score:3, Interesting)
isn't it cheaper to just buy caps insted of disposible cams
This place [torontosurplus.com] has a great supply of large high-voltage oil-filled capacitors salvaged from all sorts of stuff.
High voltage capacitors can be tough to get - Radio Shack doesn't stock many of them, and sometimes you have to buy them in bulk, which puts them out of range of most experimenters.
Microwave ovens are a great source of parts if you want to play with stuff like this, but it's worth noting that there's stuff inside microwave ovens which can kill you if you look at it the wrong way.
A full-wave rectifier made of microwave oven diodes, or a voltage doubler made with microwave oven diodes and capacitors, can be connected to an old microwave oven transformer for all sorts of fun, but can provide more voltage and current (ie. more power) than an electric chair. Be careful.
This sort of setup is great for charging up those 1uF 10kV oil-filled plastic capacitors (or doorknob capacitors [morganelec...ramics.com]) you might be able to scrounge up by looking in the right places. Oil filled caps are great because they tend to be self-healing. Blow a hole in the oil dielectric, and more just flows into place to fill it.
They're great for spot-welding.
Please don't do this if you don't known what you're doing, and I can't take responsibility for telling the wrong people stuff they can figure out from reading an electronics textbook.
Nope. Used disposables = free (Score:2)
Photo labs often have huge boxes full of used cameras, just ask for a few.
Officially they're supposed to send them back for recycling into new cameras, but it seems that their rewards for doing so aren't very great - So they usually are willing to give away a bunch for free.
Re:umm (Score:2)
Re:So where's the gun? (Score:2)
I built a very small gauss gun in high school, played with capacitors (and other high voltage devices, like the infrared viewer I built), and generally had all kinds of fun.
But I wanna see this thing fire...
Re:So where's the gun? (Score:3, Informative)
If you had, for instance, you would know he is not done collecting enough capacitors yet.
Re:So where's the gun? (Score:2, Informative)
No pictures/videos at the site mentioned in the article, but here's a different site with videos of a capacitor-powered gauss gun in action:
Re:How to build an EMP bomb 101. (Score:3, Funny)
Re:How to build an EMP bomb 101. (Score:2)
" Cool! umm
(say it fast and remember your physics)
You could build this out of ordinary car audio capacitors
Why bother? (Score:3, Interesting)
Re:How to build an EMP bomb 101. (Score:3, Informative)
Umm, minor detail I cap of hat size wouldn't have a very high voltage rating, 500V if you're lucky. Above that, and it'll likely arc across the dielectric letting out the "magic smoke".
You can hit a million volts by placing lots of 'em in series to build up the voltage withstand. Of course, you reduce the capacitance with each series connection, so you make a string long enough to withstand the voltage and then parallel strings to get your capacitance up.
At 1MV, 5F is one *whack* of charge. Wow my mind hurts just thinking about it.
Re:insane? (Score:3, Funny)
Backtrack to the parent directory (Score:2)
just slightly radical
http://obelix.cs.adelaide.edu.au/
cpu cooling using a car radiator (Score:2)
one of the parts mentioned here is labeled as such
http://obelix.cs.adelaide.edu.au/album/cooling/ind ex.html
although his working version does use something else
http://obelix.cs.adelaide.edu.au/album/cooling/ins talled/index.html
Re:anybody else get this? (Score:2)
Karma: Terrible (mostly affected by moderation done to your comments)
Obviously there's a bug in the system. -13 karma isn't terrible, it's a badge of honor.
I caught myself laughing out loud to that one!
Does that mean I am now a troll?
Somebody must have turned down the thermostat in hell!
Karma: Excellent
WTF?
Re:Robots (Score:2)
I would like to see explosives and guns allowed on those things. Of course there could be no live audience, but it would make for great TV.
Robots machine-gunning each other. Now *there* is pure geek male testosterone at its best......better than the 3 stooges.
Re:backyard... (Score:2)
Actually, the president of my old college had a great story about how old tech can be superior in performance. He was a former Deputy Dirctor of the CIA, and had some stories he was willing to tell about some of the declassified things he was involved in. One of them was the study of the first MiG fighter we got our hands on.
Back in the 60s we were afraid of these new MiG fighters the Soviets were using--they performed significantly better than out own fighter jets of the day. We couldn't figure out what it was about them that made them more maneuverable and faster, but among other things we were scared that they had more advanced onboard electronics.
We finally got our chance to find out when a Soviet pilot took a MiG to Japan to defect to the U.S., and my college president's team was called in to disassemble, photograph, and reassemble everything before the Soviets came to retrieve their fighter the next day.
So, do you know what those sophisticated electronics we were afraid they might have developed were? Vacuum tubes. Yep, those early MiGs that outperformed our own fighters were still using vacuum tubes, a technology ten years out of date; our fighter electronics had long been transistor based. The advantages of the MiG turned out to be nominal design differences and nothing more--no super-sophisticated technology at all.
So, don't knock it 'cause it's outdated tech. The proven F-18 can still kick the ass of many newer more sophisticated designs when ity comes down to brass tacks.
Re:backyard... (Score:3, Interesting)
However, vacuum tubes are highly resistant to the effects of a nuclear EMP which would have been a big concern in the 60's. The irony is that had there been a nuclear exchange the tube-based MIGs would likely have still been flyable while the 'better' American planes would have had their electronics fried.
Re:offtopic: hmm Karma has changed on /. (Score:2)
Uh bull shit;
most
And you see, we LIKE keeping track of meaningless numbers. For one thing it tells how close I am to getting my +1 rights removed so I knwo when exactly to stop telling as many people to Go Fuck Themselves quite so often and ease up on the language a bit;
besides I get to (used to get to?) do nifty statistical analysis on the numbers (in my head of course, not gonna spend time to write anything down, yeesh) and figure some shtuff out;
such as if I made a net karma Gain or Loss from posting a pro-MS post. So far in the past I have seen strong chances of me getting a net moderation UP after a thread then down, rather cool actualy.
Re:At your own risk... (Score:2)
Re:Sounds like something from Fight Club.. (Score:2)