I Just Electrocuted Myself

[nineball9]

Originally posted by: rocketPack
... but even 5v @ 1a is almost guarnteed to be lethal ...

You need to understand Ohm's Laws.

Also understand that current is a function of resistance (impedance if dealing with AC). "5v @ 1a" is something you might find as the spec for the rated output of a power supply, but without a given resistance (impedance), it is meaningless.

A 5 volt source will produce a current of 1 amp across a resistance of 5 ohms.

Go measure your own skin resistance - it will depend on its thickness and wetness among other variables - but it will exceed 20K ohms. Calculate the current a 5V source will produce through your body.

If you pierce through your skin, your body's fluids will have a much lower resistance - at least several hundred ohms however. (One web site states 500 ohms.) I don't recommend you actually poke holes in your skin and measure it though. Calculate the current a 5V source will produce though pierced skin.

Go grab the the posts of an automobile battery. You won't get a shock, much less die. An automobile battery has a nominal voltage of 12V (actual voltage is about 13.2V). Read the label on the battery - it can source several hundred amps. This is certainly greater than "5v @ 1a" - but where are all the dead auto mechanics who have electrocuted themselves?

 

[Krynis]

I got my only PC related shock from a cold cathode fan combo -_- its one of those ones with the box the light/fan plugs into with a switch that u mount at the back so u can turn it off with out entering the case anyway it was still on and powered (Come on its a cathode for crying out loud!) and some how i managed to place my thumb over the circuit or something and still not sure what happined but as u all seem to be happy saying all of a sudden BLAM i have 2 black prung marks on my thumb and my arm is tingling...

 

[DrCool]

I don't have many shocking stories to tell, but I do have one..

I was working on a friends computer, I turned it off, and unplugged everything from the wall, except the phone cable going to the modem..

well, I was obviously to dense to realize that the phone cable carries a small amount of electricity..

I wasn't working on the modem specificially but in the area near it, removing another PCI card..

After I unscrewed it, I went to pull it out, but each time I put my hand in the proximity of the modem, it felt as though something was pushing my hand away.. After 2 - 3 attempts trying to OVERCOME the sensation , I finally realized my stupidity, and unplugged the modem.

 

[fishmonger12]

****shocked.

electrocuted implies death . like the guy above said.

like executed. but with electricity. electrocuted.

yeah, i wouldn't stick my hand into something called a power supply when it was still plugged in :\

 

[jimmyj0668]

Wanna hear an old soldiers story? Back in the early 50's I was an Air Force junior airman, two stripes, and worked in airborne communications and navigation equipment on the F 86D at the time. Before the days of transistors, an aircraft radio transmitter/reciever wa a pretty hefty unit with a bunch of tubes in it. The highest power source was the transmitter section as you would imagine. The particular unit called an ARC-27 (guess what ARC stands for) was built in two layers - part of the circuitry on an upper level and the rest on a lower level. You had to turn the unit over to work on either side. On this particularly busy day I had the transmitter side up and needed to turn the unit over to do something on the other side. With screw driver in hand I grabbed the frame of the unit and started to turn it over (the frame is of course perfectly safe and is a general ground), as I did so, the screw driver point touched the cap on one of the large transmitter tubes. The screw driver went across the room at light speed and tried to take my arm and hand with it. I never, never, never did that again. Fortunately, I had released my other hand and was simply lowering the unit with the hand cupping the screw driver.

 

[Adul]

unplug it next time

 

[bobsmith1492]

Just touch a screwdriver across the high voltage caps. Then you're good to go. Switching power supplies have high voltage caps just like monitors.

 

[exorr]

In my old apartment, a renovated early 1900's building. I turned off the light in my bedroom (a wall switch) got shocked pretty bad and the fire alarm went off...

We moved out 2 months later

Edit: Wow, scary that this was my 666th post...that's a little freaky!

 

[DAPUNISHER]

"I've been giving myself elctroshock treatments"

"Up the voltage."

:laugh:

 

[kornphlake]

I met this crazy old man in mexico who worked refurbishing alternators, starters and other electric motors. He'd been doing it so long that he'd gotten to where he didn't feel electric shock, he'd grab an extension cord with the female end cut off and the wires stripped back an inch or two and plug it in to a wall outlet, then he'd proceede to touch it to the communicator and armature to test his solder joints, if he got a spark it was good and if he didn't get a spark it was bad, or the other way around. Anyway I was watching him do this and I noticed that he was holding the bare wire rather than the insulation and I asked if there was something different about the wall socket, he said no, he'd just gotten used to the feel of 110, he then proceeded to grab another plug and connect it to a 220 outlet he had in his shop and grabbed both wires with no shaking or apparent discomfort. I don't reccomend we all build an immunity to electrical shock, but it is possible to do.

 

[0roo0roo]

heh, sites that talk about fiddling with the psu tend to warn about the shock hazard. pretty much the most dangerous bit of your computer.

 

[Jeff7]

Originally posted by: rocketPack
I'm surprised how rare electrocution is... I've been shocked by tons of things.

220V pool pump
220V dryer outlet
110V wall outlet
numerous 12V batteries
etc...

But it's not the voltage that kills ya, it's the current. 100,000Volts can pass through you and not kill you (*note: i didn't say not hurt you ), but even 5v @ 1a is almost guarnteed to be lethal, whereas 200v at 5mA is likely going to be a strong tingle at best. 50mA is considered a very dangerous and is, I suppose you could say, the generally accepted "lower limit" for a "fatal shock". however, they advertise voltage because 500,000 looks more scary than 0.05

I've been told on some other forum that low voltage isn't too dangerous, at least on dry skin, because humans have fairly high resistance at those voltages. I can't say that's the same for me - I was told what a human's resistance is, a few thousand ohms or something like that. I tested myself then with a voltmeter, and I had pretty low resistance. But then, I've always been sensitive to shocks that others don't get, or can't feel, things like 9V batteries, or low-voltage power adapters.

Edit: Appears that nineball9 already addressed this. I think he's the one who told me.

 

[Hyperlite]

Originally posted by: WobbleWobble

Originally posted by: Baked
What, no pics of you looking like a treasure troll?

My hair is normally spiked anyways

hell yes, me too

 

[jpeyton]

Always unplug and discharge the PSU before working on it. Avoid directly touching any electrical component inside.