It was Taser week on YouTube, which inspired David and Patrick to look at the tech behind electroshock weapons, from cattle prods to Tasers. It's a good reminder that Amps kill, not Volts. PS - be careful when you fry foil with a DIY camera taser.
Discovery has shark week, sometime after that UF student gotta ... a quick search for "Taser on Youtube" turns up over 3000 videos. And enough questions about how tasers work floated thru email last week Producer Joey convinced us to talk about how electroshock weapons, aka Tasers, work. (BTW, Taser, much like Kleenex, is a trademark.)
The short version goes like this: depending on the model, a modern tazer fires a small pair of electrodes from 15-30 feet. They're wired to a power supply in the gun that sends 18-26 Watts thru the wires attached to the electrodes. This effectively jams your peripheral nervous systm (er, system) and causes your muscles to contract. You go fetal. The marketing material at Taser International calls it "Neuro-Muscular Incapacitation."
It's not about pain, though we understand it's rather unpleasant. ("Don't taze me bro" is a rather frightening video to watch.) This is about physically debilitating the suspect without shooting them or beating 'em with a PR-24... er, a night stick. Personally, we'll take being zapped over being shot. Mace might be better.
Avoiding any situation that might involve shooting, being zapped, maced or beaten sounds even better.
Some devices also offer a less powerful 'drive mode' that works muck like a hot shot or cattle prod: a pair of electrodes sends a high voltage low current jolt of electricity thru the skin. It hurts like heck, but you can keep moving.
We're pretty sure showing off the DIY camra-tazer wasn't our brightest act... we totally understand where Make magazine was coming from when they killed off a "lifter" project earlier this year due to safety concerns (Unsafe At Any Amperage, btw, is a great behind the scenes read, and Make rocks even harder than usual for posting the email thread that led to canceling the story.)
But, frankly, blowing holes in Aluminum foil is a pretty good way to suggest that playing with electroshock gadgetry can hurt... just because you can build it with $6 in parts doesn't mean it's a toy.
And if, like us, you like to crack things open and look inside, say, for example, a disposable camera or an old Mac, you should know that capacitors, the pointy end of the CRT/TV tube with all the wires can carry current even when they're not plugged in. Don't play with 'em if you don't know how to discharge them and handle them. Seriously. You can stop your heart.
Don't believe us, believe Ohio State's Physics Department: The Fatal Current is an excellent discussion of how a small amount of current can kill you. The The Physiological Effects of Electric Shock section is worth reading twice.
PS -- don't play with electricity while you're home alone: you can't dial 911 if you've managed to stop your heart.
PSPS -- If Law Enforcement points a Taser or a gun at you, do yourself a favor and do what they say.
Systm is the Do It Yourself show designed for the common geek who wants to quickly and easily learn how to dive into the latest and hottest tech projects. We will help you avoid pitfalls and get your project up and running fast.