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Voltage vs. current they both suck
It is a matter of annoyance to me that people say things like "It's not the volts, it's the amps that kill you." Seeing something like:
With line currents above 2 milliamperes...
points out, I think, a great deal of confusion in this matter. Line current is not important; the current through your body is important. Line voltage is important, as it in part determines the current through your body.
I don't really know how to fix this article so it is factual, but doesn't rely too heavily on explanations of Ohm's law, etc. I also don't think it should look like a compromise between the "voltage" and "current camps", since there aren't really two points of view here. Idea? [[User:CyborgTosser|CyborgTosser (Only half the battle)]] 23:38, 28 Oct 2004 (UTC)
Upon further review, I'm not sure about a lot of the information here. For example, most other sources I find list currents about 10 times here for each of the effects (about 10-15mA for unable to let go of wires, hundreds of mA for fribulation). And to say that the voltages in homes are a deadly combination seems a bit alarmist. I'm going to do some more research before touching this one. [[User:CyborgTosser|CyborgTosser (Only half the battle)]] 00:01, 29 Oct 2004 (UTC)
agreed the figures do seem a bit low (maybe they are absoloute worst cases rather than likely values or something) generally below 50V or 60V is considered to be safe for humans to touch directly
mains can be deadly it all depends on the situation and the duration but the iee seem to belive based on thier research that a RCD with a 30ma trip and a fast trip time (im not sure how fast but its documented) will in almost all cases be sufficiant to save a healthy person in the event of a mains shock (though they do say it should not be used as the sole means of protection from direct contact.
the real danger at mains voltages without rcd protection comes if a shock leaves you unable to remove yourself from the source of shock (a grab on a live conductor is far worse than touching one) Plugwash 11:20, 8 Dec 2004 (UTC)
Since mains current is AC, though, it cannot cause your muscles to contract. The alternating polarity will cancel out and you won't hang on. A strong DC current can make your muscles contract around the electrical source.
Adam85009:23, 26 January 2005 (UTC)[reply]
That's false. AC certainly can cause contraction of muscles. Muscles aren't motors, and the way in which electricity disrupts normal neuromotor control isn't a matter of superposition. --Blair P. Houghton 04:26, 28 Jan 2005 (UTC)
I removed the dispute notice as no one has edited this article or said anything on the talk page for weeks and weeks. If anyone still has a problem with the facts as presented in this article, take the usual NPOV approach and cite sources to support the sides of the argument as presented by various schools of thought on the matter. — Trilobite(Talk) 19:40, 29 Mar 2005 (UTC)
Electrocution - Electric Chair & animal use
Isn't it a bit POV to claim that throughout the world 'the Chair' is viewed as 'inhumane'? Isn't it rather the case that it's gruesome and sickening to watch (a rather different point). There is quite a bit of evidence (see ( Dr Grandin's animal husbandry web site) that an electric current of an amp or two is an efficient way of inducing unconsciousness in a large mammal, provided the current path is through the brain. (There was also at least one 19th century US medic who self-experimented (!) on the level of current sufficient to induce unconsciousness)80.177.213.144
Actually the entire concept of "capital punishment" is viewed as inhumane in most civilized countries in the world.
True (well more or less - though it wasn't the reason we in the UK abolished the penalty many, many years ago) - but in the present context, irrelevant :-) 80.177.213.144
Fibrillation
The 100 to 200 mA region for fibrillation agrees with my best recollection (ARRL handbook in days of valves/tubes?), but where's the evidence that such fibrillation 'tears the tissue' and 'destroys the heart' - I though the whole point about fibrillation was that it _could_ be stopped, by a large electric shock, from a defibrillator - though of course time is of the essence, because a heart in fibrillation pumps no blood. Linuxlad01:55, 25 July 2005 (UTC)[reply]
I am not registered at the Daily Nation and not particularly willing.
Could someone less paranoid please fetch the title and date of the relevant article, fill it in above, and move the notice to the top of the page where it belongs...
Oh yes, and you'll be able to fill in the appropriate section here as well.
Thanks in advance.
—Phil | Talk15:05, 7 October 2005 (UTC)[reply]
Breaing in mind we only respond to the current, why is it that hv shocks tend to hurt (sting) more but low voltage ones tend to 'shock' you more(ie take your breath away)?? Or is it just me? Any answers/ sugesstions?--Light current02:58, 31 October 2005 (UTC)[reply]
well I'm not sure either but with static electricity I'd guess that either its the little plasma arc that basically burns you, or the high frequencies of the transient causing a faster more painful muscle contraction, which make it hurt so much more. btw a static shock is both high current and high voltage, its just very very short. keith10:50, 3 November 2005 (UTC)[reply]
Could be that the bad shcocks Ive had have been from 240v from left hand to leg (or left hand to right hand) and those are very shocking! They take your breath away. Its also possible that these mains shocks are longer in duration than you might get from a HV capcitor of a few pF. THe HV shocks are probably limited to much less current, and if they do not pass thro the chest, just tend to sting the entrance / exit points.
Maybe we need to mention also the max safe amount of stored energy. I think its 2J.--Light current18:59, 3 November 2005 (UTC)[reply]
Impedance of the human body
I just hooked up an ohm meter to my body and it showed me these results:
Human Body Impedance Experiment Results
Body Area
Impedance
Face
1.5 Mega Ohm
Balls
2.5 Mega Ohm
Organ (the non-musical kind)
3.5 Mega Ohm
Thighs
3.0 Mega Ohm
Fingers
2.5 Mega Ohm
Soles
4.5 Mega Ohm
Feet
20 Mega Ohm to over 200 Mega Ohm (fluctuates constantly)
This data is not made up, I really did conduct this experiment just now. According to these numbers and using Ohm's law, how much current would the body be capable of letting through? Also, can someone verify these numbers? Caution: This should only be done by grown ups and NO CHILDREN. Thanks!
There isn't much point in 'verifying' the numbers. Try it again on a different day or using smooth and then rough electrodes or on skin recently washed with soap and then after washing with detergent or with a different test current or varying a multitude of other factors. The numbers will vary. The test with different test current illustrates that the body is not an ohmic material. The most important point is that the source voltage is not a useful guide to the degree of risk. The current that flows is a very rough guide, though the effects vary in an individual over a wide range unless the conditions are very carefully controlled. Controlled conditions are of course not available (except perhaps to an executioner or torturer) so one should treat any voltage over 24 volts as though it is potentially lethal. Electric shock is not the only hazard, even lower voltages can be dangerous if they cause arcing or heating. treesmill00:55, 27 December 2005 (UTC)[reply]
Thanks for your reply! It was illuminating!
Try again using wet skin, e.g. lick your fingers. I can get readings below 400K ohm that way. If I hold uninsulated metal objects in both hand, e.g. a pair of pliers, I can get the resistance between them under 100K. Wetting my lips and measring between the upper and lower lip gives 50K. Almost all the resistance we are measuring is in the outer layer of dead skin. Once that is bypassed, e.g. by sweat or other moisture or a puncture, or if contact area is increased, resistance drops sharply.--agr15:24, 30 December 2005 (UTC)[reply]
Update: I have just duplicated your experiments and you'll be pleased to know that I concur with your findings. The following are my results as conducted just now:
Human Body Impedance Second Experiment Results
Body Area
Impedance (ohm)
Between two fingers after licking them
Ohm meter consistently begins reading at 50K, and continues to rise to 170K (after which I stopped measuring). Meter was still rising when I stopped taking the measurement.
Between two uninsulated metal objects that I'm holding in wet licked fingers
Ohm meter begins at 130K, and continues to rise to 180K (after which I stopped measuring). Meter was still rising when I stopped taking the measurement.
Between upper & lower lip after wetting them with my tongue
25K
This is very cool. Especially interesting is the 25K Ohm reading between my wet lips. My faith in the veracity of this article is restored. And I really appreciate your input!
This is all assuming the body is a simple resistor though. The figures actually make it non-linear with respect to voltage, in the same way as other insulators or semiconductors - see this link which I found off Google. So the impedance at 110V is much less than the impedance at 1.5V, and as a result the effects are going to be more severe than your measurements suggest.
Question on unearthed sources
I am moving the following edit by 59.93.33.95 from the main article to here:
(The the answer for the question "How we are getting electric shock from independent voltage sources?" such as an unearthed generator unit or LPG ignitor etc are still unexplained)
In theory, to get a shock form an un-earthed (ungrounded) voltage source, you must touch both ends. However high frequency sources, such as a spark generator, will often have enough capacitative coupling to earth to cause a shock. Also a source of charge, such as lightning or a charged high-voltage capacitor, can produce a single-ended shock. Finally, one should never rely on the assumption that a particular generator is un-earthed, but always turn it off or disconnect from it before working on circuits.--agr15:24, 30 December 2005 (UTC)[reply]
