Live Electricity

[dittohead]

i was giving my friend advice over the internet about how to fix her other pc...
...and she pulled a 4pin molex straight out whilst it being on :eek:

350w generic one ;)
shes still alive :)

i was just shocked that shes alive and the machine is still running, the hdd (that was connected) was poo, anyway. has trouble writing..

any similar stories?

[ghettocomp]

4 pin molex? no problem. only around 12v and 5v
wont hurt tooo much. :)
its not like getting your finger stuck in the light socket :D

[Just Some Dude]

HeHe she sounds like me!!! :beer:

[Mr. Roboto]

Yeah, i'm not surprised at all. 12V is nothing.

Remember volts are what hurt, not watts.

[Roofles]

Yeah, i'm not surprised at all. 12V is nothing.

Remember volts are what hurt, not watts.

Wrong on both counts, current is what hurts.

[s002wjh]

yeah current will hurt and kill, not volt

[dogbert_2001]

However, current is determined by voltage and resistance. Thus:

I=V/R

Pulling out a molex isn't as different as say pulling a plug from an outlet or turning your PC off. With regards to your health, there is less insulation, but there is still some, and even if you touch a bare wire, you need to form a circuit in order to be electrocuted. With regards to the device, how else do you think hard drives turn off? Switches disconnect the hard drive from power internally, no different from pulling the plug. Devices become damaged from overcurrent, undercurrent, or wrong frequencies.

It's still a good idea to turn off and unplug your PC before working on it.

[Roofles]

The resistance of you (past your skin, is slim, ie salt water 40 Ohms) will provide enough current to kill you. 12V/40 Ohms = 300mA which is more than enough by anyone's rating for the current needed to kill you.

Your skin luckily is upwards of 10k.

this is a pretty good overview of electrical shock from allaboutcircuits.com

http://www.allaboutcircuits.com/vol_1/chpt_3/4.html

[PottaCoola]

That shocks u? iv mest with unplugin fans and hard drives with the pc on loads of times oh aand graphics card, without any probs. :)

[Roofles]

No, I'm only proving that voltage is not as significant as most people think in electric induced pain.

However I hope you turn off your computer when you pull your hard drive out =)

[PottaCoola]

Hehe i do , its only last resort thing in some testing when i do it but doesnt happen much.

[eric003]

lol, I agree with some of the other guys, 12V is nothing.. I work in a PLC engineering firm, and I touch 24V all the time.. cant even feel it.. cause there is almost no current, its all about the current.. even 120V barely will shock u as long as the current is low enough. I got a coworker here that took a shock from 480V on accident while using a multimeter. He accidentaly had his thumbs on the metal tips of the "leads" while testing some components in an cabinet. i dont know how much current it was.. but he said it shocked the SHIIIT out of him.. he didn't quite feel right the rest of the day.. but he was fine after a day. not like he dead.. lol
He also told me a story of some guys that he used to work with that were working on an old cathode ray tube and got hit with like an ungodly amount of voltage..like 50,000 Volts. but current was so low (like 1 mA maybe) that it just shocked the hell out of them and knocked them on their a$$. kinda like a stun gun for instance.. thats all they do..lots of voltage and low current.

so, in summary, nobody is gonna die from unplugging a HD while its running.. :rolleyes:

[Roofles]

so, in summary, nobody is gonna die from unplugging a HD while its running.. :rolleyes:

Correct! save some really extraneous circumstances.... but I doubt a reported case exists...

[dogbert_2001]

No, I'm only proving that voltage is not as significant as most people think in electric induced pain.

However I hope you turn off your computer when you pull your hard drive out =)

From your own link:

A common phrase heard in reference to electrical safety goes something like this: "It's not voltage that kills, it's current!" While there is an element of truth to this, there's more to understand about shock hazard than this simple adage. If voltage presented no danger, no one would ever print and display signs saying: DANGER -- HIGH VOLTAGE!

The principle that "current kills" is essentially correct. It is electric current that burns tissue, freezes muscles, and fibrillates hearts. However, electric current doesn't just occur on its own: there must be voltage available to motivate electrons to flow through a victim. A person's body also presents resistance to current, which must be taken into account.

This quote elaborates on what I was saying earlier with I=V/R. I'm just lazy and I like to be terse.

So "not as significant" may not be the correct wording here. Maybe you meant that with regards to dry skin, the order of magnitute of voltage required to harm you is much greater than current. However, any voltage can kill you if your resistance is low enough. 0.5V across the heart can kill you.

ANY VOLTAGE CAN KILL YOU. IT DEPENDS ON YOUR RESISTANCE.

[Roofles]

Yeah. I'm saying that 12V is as likely to kill you as 120V. Therefore not as significant as the current that will flow through you.

I must admit we are pretty much arguing the same thing and are just debating semantics.

[Mr. Roboto]

meh, i knew i shouldn't have posted that thing about volts haha, i wasn't too sure about it. Oh well.

[aaa]

Some time ago I attempted to plug in an hd while running (the first few times were successful). Somehow the pins didn't line up right on the molex and it short-circuited. Fortunately the psu automatically shut off.

[nvidiaOCmaster]

Ive done that many-a times, I think its pretty cool, your heart skips a beat when you receive 20A 12V+, sorta like a buzz for 30 seconds.

[Cjwinnit]

Volts just jolts.