What kills people, current or voltage? Or something else?

[c4757p]

What kills people, current or voltage? Or something else?

Something else.

Guns?

Oh wait, guns don't kill people, pe--

People.

It's people.

Stupid ones, usually.

[Mechatrommer]

People can and do die from licking 9V batteries!

Bullshit. Please stop spreading urban legends.

"urban legend" does exist... http://www.dailymail.co.uk/news/article-2950641/Woman-electrocuted-iPhone-dropped-bath-charging-looked-Russian-version-Facebook.html (sad that lady is a waste)

[VK5RC]

The most common mechanism is disruption of the normal orderly contraction of myocardial cells triggered by the electrical depolarisation of the myocardial and specialised conductive tissue.  If at very low levels (V=I. R) no effect occurs,  at high levels (briefly) the heart is 'defibrillated'  and once the external electric source stops the heart will almost invariably return to work.  At intermediate levels some sections of the heart are depolarised others are not leading to a rotating wave of depolarisation,  this causes/is fibrillation.  If this is in the ventricle no blood is pumped,   6 seconds later you pass out,  3mins later your brain is mush.

[mtdoc]

Cigarettes.

[AlfBaz]

V=IR

All three variables inexorably linked.
A high value of V alone wont kill you
A value of R alone wont kill you.
A high value of I alone will...

Doe it really need to be more complicated than this?

[nadona]

Simple. Energy kills people.
Energy = Power x time = V x I x Time
If any one of these is small enough, people don't die.

[AlfBaz]

Simple. Energy kills people.
Energy = Power x time = V x I x Time
If any one of these is small enough, people don't die.

If V=I=0 and time=some arbitrarily large number Energy will still equal 0 but given a large enough time you will still die even though Energy=0, therefor I call bullshit

[tautech]

You die by getting fried.
Warning: Content may offend.

https://www.youtube.com/watch?v=l2hPsNTFQjo&oref=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dl2hPsNTFQjo&has_verified=1

[suicidaleggroll]

Simple. Energy kills people.
Energy = Power x time = V x I x Time
If any one of these is small enough, people don't die.

And if voltage or time are large, you won't necessarily die either.  Small voltage with a small current for a very long time will do nothing, even though the integrated energy could be very large.  It's only if the current is high enough that there's a risk.

[tautech]

If you look at this Wikipedia link the graph shows a combination of Time and Current assuming a AC mains supply.
http://en.wikipedia.org/wiki/Residual-current_device

[SL4P]

You die by getting fried.

Not exactly correct.
It is well recognised that excessive dissipation of 'energy' at the points of electrical contact can in fact char your skin - BEFORE - the permanent / lethal damage is done to your internal organs & metabolism.

You mauy not have any hands, feet or fingers - but you will just have experienced a massive shock before your skin became a high-value resistor in a 'flash' literally.

[EEVblog]

Even if the current is huge, but voltage is in uV or nV?

You cannot get a large current flow through your body when you only have uV or nV applied!
In the simplest terms, the body has a high resistance, and it takes X amount of voltage to get a certain current to flow.
Over a certain current, you will likely die. This is why the earth leakage current breaker in your house is rated in current (usually 20mA or so), and not voltage.
Roughly, under 20mA = safe, over 20mA = dead.

[Stonent]

Check out Afrotechmod's video on the subject:

FTFY

[tautech]

We mustn't overlook Time.

Example
Mains powered electric fence ~ 5000V  @ up to 50 A for 1-3ms.    It won't kill you but you won't come back for more. 

[Kappes Buur]

http://support.fluke.com/educators/Download/Asset/2096653_6003_ENG_D_W.PDF

see Electric shock on page 5

[codeboy2k]

The required voltage may vary 100:1 depending on circumstances but the share of current passing through the heart is always in the neighborhood of 30mA. So, current is a much more reliable measure of potential lethality: any source capable of delivering at least 10mA with enough voltage to deliver it on-contact is potentially lethal. A 5kV source that can only provide 10mA will cause local burns but is unlikely to be lethal.

For the record.. When I was 14 I was making a Jacob's Ladder, and I was using an old oil-burner ignition transformer. I've just done some research and see that some are rated at 20 or 30mA... the one I had was only 10mA.. I remember that. 10kV , 10 mA.

When I was building the Jacob's ladder, I accidentally touched the leads with both hands. I don't know how I came in contact with the wires, but it did throw me backwards about 5 meters into a wall, and I survived. I consider myself lucky, indeed.

In my case, 10 mA was survivable. I also now know that DC tends to throw one away from the source, and AC tends to make one hold on.  But this was an AC transformer, and I did not hold on.

[opty]

V=IR

All three variables inexorably linked.
...
Doe it really need to be more complicated than this?

Just like you say
(plus: time and environmental conditions also matter (as said above).)


It is like on those 'Is BJT voltage or current controlled?' discussions. Flow of electrons is directly responsible for the effects (so it is often chosen as 'the reason') but you won't have current without voltage .... discussion goes on.

[SteveyG]

I also now know that DC tends to throw one away from the source, and AC tends to make one hold on.  But this was an AC transformer, and I did not hold on.

That's not really the case and I wouldn't draw conclusion from that one experience. DC will typically cause a singular continuous muscle contraction and it is purely down to how you come into contact with the supply as to whether you're thrown away or grab more tightly onto the source.

[JohnnyBerg]

I remember my colleges at university. There was a lecture about a striking lightning, and in the adjacent meadow cows died.
Students were shocked about these tests, and rebelled 

[timb]

People can and do die from licking 9V batteries!

Bullshit. Please stop spreading urban legends.

Actually, there is a US Navy fatality from a 9V battery. During a safety course the instructor was having technicians measure their skin resistance with a Simpson multimeter. One guy got the bright idea to jam the sharp probes INTO his hands to get a really good reading. The blood and salty fluids carried the current right through his heart and as a result, stopped it.

There is an actual report of this in Navy Archives, so no urban legend!


Sent from my Smartphone

[jpb]

People can and do die from licking 9V batteries!

Bullshit. Please stop spreading urban legends.

Actually, there is a US Navy fatality from a 9V battery. During a safety course the instructor was having technicians measure their skin resistance with a Simpson multimeter. One guy got the bright idea to jam the sharp probes INTO his hands to get a really good reading. The blood and salty fluids carried the current right through his heart and as a result, stopped it.

There is an actual report of this in Navy Archives, so no urban legend!


Sent from my Smartphone

There was a lot of discussion on the 9V battery story/account a while back on these forums. It is a rather different scenario from licking a 9V battery as you need to have good contact to internal fluids at both ends and even if you touched both electrodes of the battery with your tongue the current would flow through your tongue not your heart.

For similar reasons, unless you're very unlucky you're probably safe with low voltage sources even if you have a cut on your hand.

Conversely, there are some quite unpleasant accounts of the Electric Chair failing to kill people and typically taking 5 minutes or more even when it does.

And at the other extreme, biting on a bit of foil in say a chocolate bar when you have metal fillings can be an unpleasant experience if not lethal unless of course you're driving at the time.

[electr_peter]

let mehdi the great teach us something LOL !!!!


although it appears to be comedy, but i believe he did try to convey that low voltage is not all that harmless. it is funny that there is no real safety video that actually correlates body resistances to lethality ... and the joke is ultimately back on ourselves

I don't like that guy's videos. He obviously knows what he is doing but chooses to play idiot role in front of the camera. All videos are to show some comedy bits and some are obviously rigged. Acting is not even convincing in my opinion. You may like his videos but will probably agree that is not best place to learn about electricity for beginners.

[EEVblog]

im not sure how to comment on this video ... and half a million views !

there is another 1 at over 2million views ... crazy ...

150K more subscribers than me, he's doing something right!

[EEVblog]

I don't like that guy's videos. He obviously knows what he is doing but chooses to play idiot role in front of the camera. All videos are to show some comedy bits and some are obviously rigged. Acting is not even convincing in my opinion. You may like his videos but will probably agree that is not best place to learn about electricity for beginners.

They aren't designed to teach, it's pure entertainment and comedy.

[Wytnucls]

Your video on exploding multimeters must have brought in a few subscribers.