"Eeyore" wrote in message news: snipped-for-privacy@REMOVETHIS.hotmail.com...
Right. One nasty thing that can happen is this: Suppose you have a source of a non-lethal voltage, such as a 12-volt car battery, that can deliver tens or hundreds of amps. Short this through your ring, and even though there is no danger of electric shock, your ring becomes a heating element and burns you!
I recall an actual electrical engineer (in New Zealand) who was working up on a pole and contacted 11 kV. Supposedly the fall from the bucket restarted his heart, however he died later because many of his internal organs were cooked. Not sure how true it is but an awful warning nonetheless.
"Eeyore" wrote in message news: snipped-for-privacy@REMOVETHIS.hotmail.com...
8 mA if you are unlucky. I got a solid belt off 230 VAC that left me deaf and nauseous for half an hour. Not sure how many amps.
Mashed potatoes anyone?
You need current to cause electrocution, and voltage to force the current through the body.
As for how much of each?
How much current - depends on the path it takes, as well as current type and frequency if it is AC or pulsating DC, duration of the shock, and at what stage of the heartbeat cycle your heart is in when the jolt is applied, and maybe half a bazillion other factors. But the usually-repeated figures for 50-60 Hz AC (which is worse than DC as well as being worse than higher frequency AC), in an arm-to-arm shock through skin (as opposed to current concentrated within a blood vessel), has 100 milliamps to 1 amp most likely to kill, and generally doing so by causing ventricular fibrillation. Currents higher than this (for shock path and current type in question) have a lower fatality rate but are far from being non-deadly. Currents somewaht lower than this have a fatality rate that is lower but not zero - I have heard of someone getting killed by a 30 milliamp neon sign transformer. I have heard of 5 mA having some slight chance of causing electrocution.
As for how much voltage is required to cause electrocution? Hold ohmmeter leads and it is common to see resistance readings in the hundreds of kiloohms or megohms. This would lead one to think that hundreds of volts would cause only a few milliamps or a fraction of a milliamp to flow, with negligible chance of electrocution.
Problems here are:
1) Skin resistance varies wildly and sometimes unpredictably.2) Many electrocution deaths occur with contact area greater than that of ohmmeter lead points.
3) Flowing current, especially when higher due to higher voltages, can stimulate sweat glands and can cause electrolysis - which will increase skin conductivity. If burning or so much as significant temperature rise occurs, conductivity will increase.Keep in mind that 110-120 volts AC 50-60 Hz has a significant body count. Why? One reason is that it is so common, but another reason is that people are careless with this voltage because of the high survival rate of shocks at this voltage.
As for how much voltage is hazardous? 50 volts is widely repeated as the point at/above which one normally needs to be careful to avoid electric shock. However, I have heard of a US Navy rule requiring "DANGER
- HIGH VOLTAGE" signs where voltages 29 volts or higher were present where people could possibly make contact. Of course, with large contact area wet with salt water, electrocution by lower voltages is possible.
- Don Klipstein ( snipped-for-privacy@misty.com)
My old teacher used to say:
"It's the volts that jolts and the mils that kills"
Mr. J D schrieb:
Volage is the basis that current can flow. As said also small currents can be dangerous, e.g. 5mA through your heart. If you have dry skin, you may touch 220V without damage to you, because the current was small. Dry skin is a good insulator.
So 27000V from a TV line transformer will not hurt you. It can only supply 1-2 mA. But the first touch is shocking, due to the capacitance of the pic. tube, like a teaser. But don't try 20000V of a power distr. transformer, that can supply
100rds of Amps.
The real deal is current through your heart causing it to go into fibrillation. I can't recall the exact figures now, but something like
5-100 mA is the critical zone, however, timing of the shock and if it's AC or DC all help determine if the heart starts to fibrillate.Currents over 100mA or so, clamp the heart muscles hard and so act like a "reset" That's why it's possible to survive very serious shocks (with a LOT of luck) But then again, too high, or too long and your internal bits start to bake. That's also why defibrillators work, they deliver a carefully controlled and timed pulse to do the "reset"
Of course the source must have low enough internal impedance to deliver, that's why 15Kv off a TV just stings. However 2Kv of a charged microwave oven cap has killed.
The current is determined by the efficiency of the contact and your skin resistance. There are a few rare cases of fatalities from 70-80 volt welders, but 200-400 volts are the most common
Barry Lennox
Or metal watch bands or bracelets.
They claim to be the most trusted news source - but if you can't trust them how can you trust that claim?
The same ground covered in different words by Paul ( snipped-for-privacy@smart.net) in the same thread:
You can stand in a lake of millions of gallons. No problem.
Try it in a river at full flood. Big problem.
Pressure kills.
The girl i chased when I was a teen, she can have 10 KiloVolt across her heart with no damage, finally I gave her up
So what's the arm to arm resistance once the skin resistance is removed by electrode penetration? I thought it was around 100R, which could provide a potentially lethal current.
-- Dirk http://www.onetribe.me.uk/ - The UK\'s only occult talk show Presented by Dirk Bruere and Marc Power on ResonanceFM
draw some blood onto a glass slide and measure its resistance over say
5mm. Then perhaps multiply it by the appropriate number to get an aproximate internal body resistance.Wont be that accurate for sure, since it doesnt take into account resistance of nerves etc (which might be lower).
In message , dated Mon, 28 Aug 2006, Homer J Simpson writes
NO media people know anything about technology, of if they do, they keep very quiet about it. Everything has to be dumbed-down, just in case someone gets a tiny bit confused.
-- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
What a bunch of armchair theorists! Doesn't anybody own a Fluke with sharp probes?
I do. Pushing up to my pain threshold on both thumbs, Fluke 87 on ohms/autorange, wet thumbs for good measure, I can get down close to 3 megs. If I put both probes on my tongue, I feel nothing. Open-circuit voltage is highest on the diode range, at +3.75 volts.
If a handheld Fluke had ever injured anyone, don't you think the Fluke manual would be full of dire warnings? It ain't. And a Fluke outputs well under a mA on any ohms or diode range, if only to save battery life.
Urban legend.
John
What's the resistance of a piece of wet raw steak?
-- Dirk http://www.onetribe.me.uk/ - The UK\'s only occult talk show Presented by Dirk Bruere and Marc Power on ResonanceFM
Do you have a fluke? Do you have steak? Tell us!
John
I've never eaten it that way.
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