AudioFreak said:
Sure, it CAN burn but for most people you have to have a very specific situation for it. I, when I was 15 I should probably mention, hooked my left arm up to my PSU which gave me 50 VDC which I connected with alligator clips 2 cm from eachother (yes, it hurts a bit when the clips dig into your skin) after wetting the arm really well. I could by doing this control the muscles by adjusting the voltage and it was really hard to resist. Obviously in this case I got a burn and it took maybe 5 years before they were gone. Obviously a thing you should NOT try. Normally however I don't even feel it.
As they say: Curiosity killed the cat and burned his owner.
Same disclaimer as my previous post. DON'T EVEN THINK ABOUT IT.
Most dangerous shock
The most dangerous way of getting a shock is between the two arms ( or hands). The current passes through the heart ( in between) and kills the heart muscles. Depending on the temperatuire you will live for a few minutes ( 2~3 minutes in warm climates) before you collapse and DIE. The brain lives a bit longer after the heart stops. There is supposedly no way this can be reversed. I know , I lost a very dear cousin that way. So in a high voltage situation keep one hand behind you !
The most dangerous way of getting a shock is between the two arms ( or hands). The current passes through the heart ( in between) and kills the heart muscles. Depending on the temperatuire you will live for a few minutes ( 2~3 minutes in warm climates) before you collapse and DIE. The brain lives a bit longer after the heart stops. There is supposedly no way this can be reversed. I know , I lost a very dear cousin that way. So in a high voltage situation keep one hand behind you !
i wish there were more readers
I used to repair o'scopes, and worked as a LAB RAT in Physics. I never stick two hands into any device and always double check to make sure that something isn't plugged in.
I daresay I have seen the wrong end of a high voltage circuit more than once. A rubber mat is good to stand on and relieves fatigue, a cement floor is a surprising good conductor if the humidity is high enough (some tradeoff between static and humidity.)
This rule is probably never obeyed by DIY'rs -- but you really shouldn't work on this stuff if there isn't someone else around.
I used to repair o'scopes, and worked as a LAB RAT in Physics. I never stick two hands into any device and always double check to make sure that something isn't plugged in.
I daresay I have seen the wrong end of a high voltage circuit more than once. A rubber mat is good to stand on and relieves fatigue, a cement floor is a surprising good conductor if the humidity is high enough (some tradeoff between static and humidity.)
This rule is probably never obeyed by DIY'rs -- but you really shouldn't work on this stuff if there isn't someone else around.
Current
The current involved is relevant as well. Ever seen photos of someone with long arcs flying off the finger tips with no appearent harm? To get that effect you need thousands of volts but minusule (virtually no) current. At the other extreme, you may have read that "judicial interviews" are conducted in some parts of the world with the assistance of an auto battery, a mere 12V.
The current involved is relevant as well. Ever seen photos of someone with long arcs flying off the finger tips with no appearent harm? To get that effect you need thousands of volts but minusule (virtually no) current. At the other extreme, you may have read that "judicial interviews" are conducted in some parts of the world with the assistance of an auto battery, a mere 12V.
The lesson should be
to the newbie - and the one that all of us should spread when ever possible. ALL of this is dangerous. Some more so than other bits, but whenever you are working with electricity, use your head. Pay attention to the work, and only the work.
I suspect all of us can tell war stories - I learned at the knee of my Grandfather working on live main equipment who taught me as a young man "if you see me grabbing hold of a wire and not letting go, kick me as hard as you can." I have had to kick people while working live sound - the electrician had his hand in a panel with 3phase 208 with 1400amp breakers, and it did not want to let go. It was a horrible burn but he lived.
But thats war stories.. I have no doubt that in the right circumstances, the powersupply from the smallest gainclone is capable of killing you. Respect it, and you will be fine.
to the newbie - and the one that all of us should spread when ever possible. ALL of this is dangerous. Some more so than other bits, but whenever you are working with electricity, use your head. Pay attention to the work, and only the work.
I suspect all of us can tell war stories - I learned at the knee of my Grandfather working on live main equipment who taught me as a young man "if you see me grabbing hold of a wire and not letting go, kick me as hard as you can." I have had to kick people while working live sound - the electrician had his hand in a panel with 3phase 208 with 1400amp breakers, and it did not want to let go. It was a horrible burn but he lived.
But thats war stories.. I have no doubt that in the right circumstances, the powersupply from the smallest gainclone is capable of killing you. Respect it, and you will be fine.
i never touch anything with mains in it while its pluged in, but i can tell you, 230v AC stings and burns like hell, i stuck my finger in an empty light socket when i was younger 
i was messing aroung with this mains motor (not connected) and i put it in the palm of my hand and turned it, my hand had a spasm and i dropped it, it stung too, it turned out the connectors had touched my skin and it was acting like a generator.
i was messing aroung with this mains motor (not connected) and i put it in the palm of my hand and turned it, my hand had a spasm and i dropped it, it stung too, it turned out the connectors had touched my skin and it was acting like a generator.
Skin resistance and that of your bloodstream is quite different. Resistance on your skin is about 500K to 1M ohm. Your bloodstream on the other hand is about 100ohm, a very good conductor. I read once about someone who tried to measure his "internal resistance". He stabbed his thumbs with the leads of a 9v multimeter and fell over dead.
Amusing Shock's
Hi All
I’ve Had One or two belts My Self Over years Best one I think was the tin of switch cleaner and forgetting to switch of the mixer. Hmmmmm wallop and when I was a DJ my sound engineer was repairing a speaker lead he was on this knees looking for the wire stripers in the dark room he pared the wire with you gess it this teeth he found out he cood hover in the days when the mans wire was brown and twisted together A friend of mine got his sister to touch the bare wire to see which was the live Ha Ha I liked that one
Hi All
I’ve Had One or two belts My Self Over years Best one I think was the tin of switch cleaner and forgetting to switch of the mixer. Hmmmmm wallop and when I was a DJ my sound engineer was repairing a speaker lead he was on this knees looking for the wire stripers in the dark room he pared the wire with you gess it this teeth he found out he cood hover in the days when the mans wire was brown and twisted together A friend of mine got his sister to touch the bare wire to see which was the live Ha Ha I liked that one
Re: Shocks
Maby you should invite him over, and get him to help you "hold a thing" for you.
No, just show him this:
:http://vatican.rotten.com/powerline/index.html (not for the faint-hearted)
That would tach him.
colin.hepburn2 said:
Maby you should invite him over, and get him to help you "hold a thing" for you.
No, just show him this:
:http://vatican.rotten.com/powerline/index.html (not for the faint-hearted)That would tach him.
Ok, now for two more of my cents.
Generally speaking, anything less than 70V won't hurt much (so I heard). EVERYBODY IS DIFFERENT, SO THE ONLY WAY TO BE SURE IS TO TRY IT. As totally unsafe as that is, it's the ONLY way you can be sure of what YOU are capable of handling.
The best solution is avoiding it so you don't shock yourself in the first place, of course.
CURRENT KILLS. So what. A car battery can push more than FIVE HUNDRED AMPERES. I can put my hand across the terminals and not feel a damned thing.
This is due to one single overriding rule of electronics, applicable in nearly ALL cases: OHM'S LAW. I = V/R.
The problem, of course, being that touch resistance varies an incredible amount. As high as 1M or more for a light, dry touch; the lowest I've measured is 10k across my tounge (it tingled a little due to being an analog VOM ). Resistance might drop as low as 100 ohms once the skin is punctured (arc or mechanical penetration via sharp ends), as shown by tests on raw meat.
AND BTW.
At >200kHz, skin effect is sufficient that you'll never feel it anyway. Ever seen a guy stand on a Tesla coil and display fans of arcs breaking off his hands?
Seemingly similar but not are RF burns: I have personally experienced this while working on a small VTTC. The heat from the arc (and concentration of current at the point of contact) burns the flesh. You don't actually feel anything here either (though it may hurt a bit during the healing..).
Tim
Generally speaking, anything less than 70V won't hurt much (so I heard). EVERYBODY IS DIFFERENT, SO THE ONLY WAY TO BE SURE IS TO TRY IT. As totally unsafe as that is, it's the ONLY way you can be sure of what YOU are capable of handling.
The best solution is avoiding it so you don't shock yourself in the first place, of course.
CURRENT KILLS. So what. A car battery can push more than FIVE HUNDRED AMPERES. I can put my hand across the terminals and not feel a damned thing.
This is due to one single overriding rule of electronics, applicable in nearly ALL cases: OHM'S LAW. I = V/R.
The problem, of course, being that touch resistance varies an incredible amount. As high as 1M or more for a light, dry touch; the lowest I've measured is 10k across my tounge (it tingled a little due to being an analog VOM
). Resistance might drop as low as 100 ohms once the skin is punctured (arc or mechanical penetration via sharp ends), as shown by tests on raw meat.AND BTW.
At >200kHz, skin effect is sufficient that you'll never feel it anyway. Ever seen a guy stand on a Tesla coil and display fans of arcs breaking off his hands?
Seemingly similar but not are RF burns: I have personally experienced this while working on a small VTTC. The heat from the arc (and concentration of current at the point of contact) burns the flesh. You don't actually feel anything here either (though it may hurt a bit during the healing..).
Tim
"Skin resistance and that of your bloodstream is quite different. Resistance on your skin is about 500K to 1M ohm. ......"
As a result, a precaution many don't think of is to cover any open wounds with a bandaid (sticking plaster on some continents and islands). "Open wound" includes something as minor as sraped knuckes, paper cuts or even hang nails.)
As a result, a precaution many don't think of is to cover any open wounds with a bandaid (sticking plaster on some continents and islands). "Open wound" includes something as minor as sraped knuckes, paper cuts or even hang nails.)
OK, lets see if I can get it right this time. What I meant to say was that the same amount of current at 1Mhz will do far less damage to your body than the same current at 60hz because of the way your body reacts to it. Notice, Ohm's law doesn't apply here because I'm not talking voltage. It is possible to pass the same amount of current through two people using different voltages but the same current at 60hz will do far more damage. Also, instead of the word impedence, I think you're looking for the word reactance. The body's resistance may be different at different frequencies, but we're talking identical amounts of current (not voltage) at different frequencies will do varying amounts of damage.
my teacher once said that minus ( - ) is the same as ground.
is this true?
otherwise where do you connect the ground if you dont have grounded sockets at home?
You dont want to get anything mixed up and produce a killing machine
I know a guy that got a hell of a lot of electricity through him and fell off one of those tall things you have on construction-sites.
he broke his neck.
but survived, lucky thing he fell down
is this true?
otherwise where do you connect the ground if you dont have grounded sockets at home?
You dont want to get anything mixed up and produce a killing machine
I know a guy that got a hell of a lot of electricity through him and fell off one of those tall things you have on construction-sites.
he broke his neck.
but survived, lucky thing he fell down
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