Build Your Own Stun Gun

mariox19 writes "Wondering what to do with your disposable camera when you're finished with it? TechTV has an article describing how to reach out and zap someone with a home-made stun gun. I discovered the link via Bruce Schneier's latest Cryptogram, where Schneier half-jokingly warns not to let airport security find out about this, lest (in their 'wisdom') they ban cameras along with nail clippers."

Re:Wow

[LostCluster]

As the article demonstrates, any time you can get a battery, capacitor, and some wire together, you have the resouces to make a simplistic taser.

I don't know any way they'd be able to regulate those situations, since capacitors of some type are found in nearly every electronic device. Anything that has to have a "flash" of power has a high-voltage capacitor behind it... the cammera flashbulb being the most typical example.

I imagine

[Anonymous Coward]

that anyone who has ever taken a disposable camera apart has experienced this-- and they'd know that it will only make an attacker madder, not "stunned".

Re:Only weak in the knees

[gooberguy]

True, it wasn't as effective as a normal taser, but with a larger capacitor it could have more than enough zap to stop a person's heart. Also, the victim was shocked on his arm, not his chest or head. I have a feeling a good torso hit would be much more effective.

Awe Man!

[bedammit]

Ok Im a photographer and this sucks. Sure I've know about this for years. While we are at it.. we should inform national security about several other things that can be made into dangerous items. Rubber bands (Useful to construct projectiles) Ethernet cable, shoe string, belts, power cables (good for strangling) lighters (duh) alcohol (useful with lighters) coke bottles (useful with lighters) T-shirts (useful with lighters) (If you didnt get the one above Molotov cocktails) hmm I just realized this list can go on and On.. I watched a lot of MacGyver, James Bond and Mr. Wizard BeDammit BeOS is reborn and its called Zeta www.yellowtab.com

Re:All battery devices?

[UpLateDrinkingCoffee]

And just what kind of threat does a stun gun pose to deserve such a measure? I mean really, people are always going to be able to do all sorts of harm to others. Trying to attain security by micromanaging everyone's actions is just not a working solution. Sure, it's sensible to ban handguns and large kitchen knives from airlines, but battery operated devices? Nail clippers?? Long fingernails could do more damage than the clipper.

Re:Wow

[irokitt]

You know, the capacitors in a CRT monitor contain more than enough juice to kill a man. Just something to keep in mind...

Re:Could they get banned at airports?

[John Hasler]

> There are lots of ways to hide explosives in
> seemingly innocent objects.

It's clear, then. We must immediately ban all seemingly innocent objects.

Idiots.

Correct me if I'm wrong, but...

[Anonymous Coward]

Isn't a stun gun a device that is supposed to stun people?

You know, "stun" them to the point where they are incapacitated?

I've worked in a photo lab and those charges annoy you, not "stun" you.

It would be like loading 20 spitballs into a big straw and calling it a shotgun.

Re:Could they get banned at airports?

[drinkypoo]

The way to get around it: Put one or two 1.5V watch batteries (wired in parallel) in the battery's can. They'll be able to run a small device just fine. If you put a little inverter circuit in there (easily done using surface mount components) you could even use it to zap the explosive when you pumped the voltage up a little bit. It seems to me like verifying that the batteries work is the least they can do.

Re:Could they get banned at airports?

[cybermace5]

Well, the conclusion to all this is to strip everyone at the terminal, run them through an x-ray machine (or hold them under observation for 24 hours to allow any suspicious objects to pass), and give them paper gowns to wear during the flight.

Maybe extend the observation phase to birth.

Re:I wouldn't do this...

[greenrom]

The voltage (the main item of concern) decreases by the function V=emf*(e^(-t/RC)) ... In other words, electric potential across the terminals decreases exponentially.

But if the capacitor is disconnected then the R in your equation is going to be a huge number. The voltage will still decay exponentially, but because the time constant is so big, it can take a while. As an example, if R is 10 megaohms and C is 100 microfarads, then it will take 1000 seconds for the capacitor to discarge to 37% of its starting voltage. So in this example, if the capacitor was initially charged to 600V, then 15 minutes after it was disconnected it would still have well over 200V left to shock you with.