pesco at May 12th, 2014 14:22 — #1
jardine at May 12th, 2014 14:51 — #2
However, the pen did not contain only a AAA battery, Brady wrote — it also contained a transformer that boosts the battery voltage to up to 750 volts.
wearysky at May 12th, 2014 14:52 — #3
Human nervous systems != cow nervous systems.
Also, I have hazy high school physics memories (please forgive me, this would have been nearly 20 years ago) that it was current, not voltage, that mattered? Am I wrong on that?
Edit - aaaand also the transformer that boosts the voltage up to 750V. Helps if one would RTFA, I guess.
brainspore at May 12th, 2014 15:00 — #4
I wonder if the power plant's attorney responded by attaching a milking machine to the nipples of the dairy farm's witness.
spunkytws at May 12th, 2014 15:09 — #5
morcheeba at May 12th, 2014 15:50 — #6
Yep, people always bring that up and it's hard to explain. Technically, it's true. But a AA battery can easily deliver 1000's of mA in current when only 30mA can kill you... but clearly no one is dying from AA batteries alone. The trick is that the body is not a particularly good conductor, so to get that kind of deadly current you need a high voltage to force the electrons through your body.
It's kinda like saying the weight of a penny can kill you. True, but only if it accelerated to a high enough speed to penetrate your skin.
bobknetzger at May 12th, 2014 15:57 — #7
The article states that the attorney was "charged" with "battery of a witness."
Brings to mind some potential Paul Coker -style electricity/law jargon pun cartoons.
Grounded in fact.
Charging a suspect.
Resisting an officer.
Enforcing a current law.
Impeding someone's speech.
jorpho at May 12th, 2014 16:35 — #8
I have one of the pens pictured. It actually uses three button cells and a capacitor and is a handy means to keep myself awake during meetings.
I kind of wish I could find a cheap one that uses an AAA battery. The button cells don't last very long and they're kind of expensive. I suppose I could just build an appropriate device myself, but I have no idea how to work out the specifics.
gilbertwham at May 12th, 2014 18:15 — #9
Bulky, but you can pretty much wire up the transformer from an old radio backwards (I once did this, and covered it in extraneus junk like old calculator screens and variable resistors and so forth, and convinced my little brothers it was a lie-detector. Fun times).
anthonyc at May 12th, 2014 21:13 — #10
A AAA battery and a transformer. Then it also contains a tiny inverter? Or is the "transformer" really a diode/capacitor voltage multiplier?
teapot at May 12th, 2014 22:48 — #11
The button cells are kind of expensive only if you buy them like a sucker
phasmafelis at May 12th, 2014 23:00 — #12
That's a really good idea. Where can I get one?
jorpho at May 12th, 2014 23:29 — #13
Well, if your local dollar store doesn't have them, the various Hong Kong exporters do.
(They're quite reliable; just don't expect your item to arrive promptly.)
...And wouldn't you know it, they advertise that one as using an AAA battery! Think I'll order one. The reviews suggest the description is inaccurate and that they're still shipping the button-cell model, as pictured in the accompanying video.
danegeld at May 13th, 2014 01:58 — #14
Reading this article, all I can say is
Teh Stupid! It burns!
yoderofkansas at May 13th, 2014 02:56 — #15
Guessing they meant a capacitor, since transformers don't do jack with DC unless, as you said, they used an inverter. Be easier to just store the charge in one or more caps in parallel to magnify the voltage/current.
danegeld at May 13th, 2014 03:26 — #16
The flyback voltage on an inductor would also work - if the current flows when the top of the pen is pressed and is then interrupted, you get a voltage spike proportional to the rate of change of current, eg current dropping from 1 amp to nothing in 1 millisecond would give 1000 volts. It would need no other electronics than a battery, coil and switch.
moriash at May 13th, 2014 07:51 — #17
Danegeld is right. I bought one at the local dollar store that looks similar to the one pictured. The innards are a relay and some clever wiring. (No capacitors, inverters or other electronics.) When activated, the circuit closes, activating the magnet in the relay. That instantly breaks the circuit, causing the voltage to spike in the electromagnet coil in the relay- an inductor. Since the user's hand is part of the circuit, he'll feel the shock each time the inductor switches over. As long as the victim presses the button, it'll keep flipping the relay back and forth, delivering a series of pulsed charges to his hand.
wearysky at May 13th, 2014 09:10 — #18
pesco at May 17th, 2014 14:22 — #19
This topic was automatically closed after 5 days. New replies are no longer allowed.