Death from Low Voltage electrocution??
WillieWonka
| Posted in General Discussion on
Here is a local story in my area of the woods. I’m quite curious, is it possible to be electrocuted to death from “low voltage electrocution?”
http://www.pennlive.com/midstate/index.ssf/2009/10/student_electrocuted_at_delawa.html
If at first you don’t succeed, try using a hammer next time…everything needs some extra persuasion from time to time. -ME
Replies
Bet that 110 is considered low voltage in the context of forensics... just like the signs on transmission towers that announce "high tension/voltage". Although you can certainly be killed by less...
PaulB
http://www.makeabettertomorrow.com
http://www.finecontracting.com
It is the amps (actually miliamps) that can kill you - not the voltage.
From an engineering point of view, low voltage is anything below 1000VAC, medium voltage is 1000-38,000VAC and high voltage is 38,000VAC and up. These boundaries vary somewhat depending on which standard you go by.
Electrocution is really a factor of current, not voltage - you could grab on to a thousand volt power source and if the current is low enough you'll be fine. More than 50 milliamps is generally considered enough to kill you.
I have tried and tried to understand voltage and amps and seem to never get it. Voltage is pressure, or so I thought, like water pressure. Amps I thought is merely a measure of power used. I give up.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
Voltage is analogous to water pressure
Amperage is analogous to volume of water
Wattage is the measure of power usedA lot of water at low pressure can exert a lot of force; so can a little water at very high pressure. BruceT
The old analogy comparing electricity to water is like this, from howstuffworks.com:The voltage is equivalent to the water pressure, the current is equivalent to the flow rate, and the resistance is like the pipe size. There is a basic equation in electrical engineering that states how the three terms relate. It says that the current is equal to the voltage divided by the resistance. I = V/rLet's see how this relation applies to the plumbing system. Let's say you have a tank of pressurized water connected to a hose that you are using to water the garden. What happens if you increase the pressure in the tank? You probably can guess that this makes more water come out of the hose. The same is true of an electrical system: Increasing the voltage will make more current flow.Let's say you increase the diameter of the hose and all of the fittings to the tank. You probably guessed that this also makes more water come out of the hose. This is like decreasing the resistance in an electrical system, which increases the current flow.Electrical power is measured in watts. In an electrical system power (P) is equal to the voltage multiplied by the current, P = VIThe water analogy still applies. Take a hose and point it at a waterwheel like the ones that were used to turn grinding stones in watermills. You can increase the power generated by the waterwheel in two ways. If you increase the pressure of the water coming out of the hose, it hits the waterwheel with a lot more force and the wheel turns faster, generating more power. If you increase the flow rate, the waterwheel turns faster because of the weight of the extra water hitting it.
Volts is pressure, amps is volume and watts represents the size of the motor running the pump. Resistance is the inverse of the size of the pipe.a pump will move a bunch of water through a big pipe with little pressure. To get the same amount of water through a small pipe you need a lot of pressure.To get back to the dead guy. It is possible to get the 100ma or so of current necessary to kill you from 12vac but you would really have to work at it. These are the kinds of things associated with swimming pools and such and even then it is usually more than casual contact.
I'm glad I read the story of the guy dying because I always thought low voltage was fine. If I work on Low Vol systems again I'll have better respect, like landscape lighting or undercab lights. Gheesh.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
I'm an electrical engineer, and I really don't worry when working with 12V or less. At 24V I do think a little bit about whether my skin is wet or not, but if my skin's dry (with no cuts) I don't worry much. Get above 30-40 volts and I take a few more precautions, and anything above maybe 60V I regard as "hot" like regular 120.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
"ANY electrical shock has the potential to cause injury to humans...doesn't matter if it's 120 volts AC ...or even 12 volts DC...both can cause injury or even fatalities.
(for example, lightning is DC...and it kills hundreds of people every year...as does regular 120 volt household AC)The amount and kind of injury depends on six things - voltage, amperage, resistance, type of current, path of current, and duration of exposure.It has been found that as little as 20 milliamps can be fatal...especially if the duration is fairly long. Anything above 60 milliamps can be quickly fatal...just a few seconds.5 milliamps is the point at which we definitely feel the shock current...enough to definitely get your attention - but you can let go of a live wire with 5 milliamps of current on it and it is rarely fatal.In the 5 to 20 milliamps range - you begin to no longer be able to control your muscles...and often can't let go of the live wire....and if enough time passes (before the power is shut off or someone knocks you clear) - this shock CAN do extensive damage...and CAN be fatal.20 - 60 milliamps can be fatal within a few seconds...it can cause fibrillation (where the heart pumps little to no blood)...and can completely stop the heart.This is why CPR training has become a requirement for most electricians...(it should be for ALL)....to possibly revive someone's heart who has been shcoked.Anything from 60 milliamps on up is generally considered fatal...and will stop the heart of even the most healthy people...in under 3 seconds. "http://experts.about.com/q/Electrical-Wiring-Home-1734/dangerous-amperage.htm---- "Currents of approximately 0.2 A are potentially fatal, because they can make the heart fibrillate, or beat in an uncontrolled manner.""In general, for limb-contact electrical shocks, accepted rules of thumb are: 1-5 mA is the level of perception; 10 mA is the level where pain is sensed; at 100 mA severe muscular contraction occurs, and at 100-300 mA electrocution occurs.""At currents as low as 60 to 100 milliamperes, low-voltage (110-220 volts), 60-hertz alternating current traveling through the chest for a split second can cause life-threatening irregular heart rhythms. About 300-500 milliamperes of direct current is needed to have the same effect."http://hypertextbook.com/facts/2000/JackHsu.shtml
You're close.
Voltage is very much like pressure.
However, amps is a measure of current, which is analogous to flow, say, gallons per minute. It can actually be converted to electrons per second.
Like pressure, voltage drops throughout a circuit. So if you had a pipe of pressurized flowing water the pressure would drop along the length of the pipe from friction just like the voltage along a wire drops from resistance. If you insert a device that draws a lot of energy out of a circuit the voltage drop a lot. For example, in a pipeline of flowing water you inserted a turbine (like a turbocharger) that use the energy from the water to power a grinding stone the pressure at that turbine would drop a lot, just like if you put a motor in an electrical circuit the voltage across the motor drops a lot.
In current, the same current has to flow everywhere in a circuit. So the current that leaves your circuit breaker, travels along wires, through a switch, to a lamp, and then back to the main panel is exactly the same everywhere in the circuit. The only time it wouldn't be is if there was a "leak" somewhere, where the current went where it wasn't supposed to go, such as a loose wire in contact with the electrical box.
Power is something different. It's the amount of energy used per unit of time. Let's say you have to lift sacks of cement from the ground into the back of your truck. You have to expend a certain amount of energy to raise the elevation of the cement a few feet. If the bed is 3 feet high and the sack weighs 94 pounds than the energy needed is 3 feet x 94 pounds = 282 foot-pounds. The amount of energy is the same regardless of how fast or slow you do it. But the rate at which you put the energy into the lifting is a measure of power. To do the lift in one second you'd have to supply energy at a rate of 282 foot-pounds per second, thus your power is 282 foot pounds per second. If you wanted to do the lift in 1/10 second, then you'd supply the same energy, but faster. The energy would still be 282 foot pounds, but the power would be 2820 foot pounds per second.
One of many units of power is horsepower. It's equal to 550 foot pounds per second. To lift your sack of cement in one second you need to supply 282 foot pounds per second which equals just about 1/2 hp.
The electrical unit of power is watts. A watt is equal to .738 foot pounds per second. So in our cement example, power would be 282 ft-lb/sec = 1/2 hp = 382 watts to lift a sack in one second.
If you know the voltage and the current you can calculate watts directly. Power = voltage x current. So if you put 120 volts across a light bulb that sucks energy at the rate of 100 watts it would take 100 watts / 120 volts = 0.83 amps of current flowing through the bulb to light it.
I could say more, but don't want to be long-winded or confusing. Hope this helps.
in your comparison to water and plumbing, amps is flow rate
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Electrocution is really a factor of current, not voltage
Well, you're half right.
The correct statement is "It's the current amount and path inside the body due to the applied voltage that kills."
Rant follows:
I really hate and detest that new adfage "Current kills, not voltage," because it is so misleading.
It makes it sound like grabbing 1000 VAC is ok, while touching a 700 amp source like a 12VDC battery will definately kill you.
Nobody ever makes the distinction that Current inside the body kills. They always ignore the fact that it's Voltage applied to the body that drives the killing current inside.
Thay alway ignore the fact that finding a voltage strong enough to drive that current that also is restricted from supplying that current is extremely rare. In truth there might be 2 applications world wide where that situation exists.
Ok. I exagerate, here might actually be 8 such situations.
IMO, it's exactly like saying "Bullets don't kill, it's the body accepting them." Substitute "Voltage" for Bullets" in that statement and see what I mean.
People think about the thing they are grabbing, not the exact scientific results inside their body that will be determined by a host of factors only to be determined by Kirchoff's and Ohm's Laws.
Rant over.
If everybody will remember that we are talking about what is in and on that wire we are thinking about touching, repeat after me:
Voltage Kills
voltage Kills
Voltage KillsSamTA Pragmatic Classical Liberal, aka Libertarian.
I'm always right! Except when I'm not.
Usually I never find any disagreement with any of your technical points Sam, however;
Thay alway ignore the fact that finding a voltage strong enough to drive that current that also is restricted from supplying that current is extremely rare. In truth there might be 2 applications world wide where that situation exists.
Here is a short list of mostly common items everyone is familiar with (just 10 items, which is more than 8, <G>), all of which are well over 1000V but are current limited (by circuitry, source impedance, reactance, or other means) to less than 10 mA, which is not fatal to 99.99999% of the population :
have personally made contact with all of these except the supply on a powder paint power supply and am still here; Note that the load impedance for all of these application is very low, much less than 10 mA except for some production paint spray booths.
Air ionizer (2kV to over 30 kV) *
bug zapper (never measured one of these)
neon signs (typically 15 to 30 kV) * to ***
Copy machine (6kV typical) *
CRT supply in B&W or color TV's or monitors (been bit by these lots) 15kV to 30 kV. * for B&W or small monitors, mostly *** for color or big monitors
Plate of 6BQ6 on flyback oscillator on old tube TVs over 15kV at 15kHz - no shock sensation, but nasty ssurface burn (e.g skin effect)
Ignition coil on cars, 40 kV typical *
Oil furnace ignition xfmr (have also been bit by this one lots, 10kV) *
Electrostatic air cleaner, 10kV typical *
Powder coat paint spray outfit. over 1kV to above 50 kV
NOTE: a microwave oven (7kV) does NOT go into the 'safe' category!!! Lotsa actual fatalities from DIY on mircowaves for folks who are not aware of the hazards!!
EDIT the asterix (*) means it is not even unpleasant, (***) means it is VERY unpleasant.
Edited 10/12/2009 12:05 pm ET by junkhound
Historically, many electrocutions have occurred from TV sets, though it's hard to say how many were due to HV vs just the B+ supply. Probably the HV supplies of the past were not current limited very well.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
I've been shocked by a vehicle's ignition system. When I was a young kid pumping gas at a service shop, a customer came in one night and said her car wouldn't turn off. She handed me the key as proof. I called the boss up and asked how I should turn the car off. "Pull the coil wire off the distributor," he says. Not knowing any better, I did exactly as I was instructed. Man, that shock hit hard! That's when I realized the boss had set me up. When I came in to work the next day, the boss was laughing his butt off when I told him what the shock felt like.
Don't really know what kills you and try to avoid contact.
Have "felt", 120vac more than once.
I cannot "feel" 12vdc with dry hands, but with the right conditions it can certainly hurt you, at least indirectly.
To wit:
In a previous life while working on commercial fishing boats, I was in the engine room sandwiched between two Cat diesels with 12v starters and alternators. We were underway with one engine running and it's alternator was maintaining the voltage in our 3 - 8D sized battery bank at 14.3 vdc.
I have no idea what the amp rating of an 8D battery is - just that it is about 4 or 5 times the size of a normal car battery - let alone what 3 batteries in parallel plus the contribution from the alternator equals.
I had ascertained that the reason that the starboard engine would not crank / start was due to a loose and slightly corroded positive battery connection at the starter.
I was covered in sweat due to an ambient room temperature above 120*, having cleaned the connector, I was tightening the connection with a box end wrench in my right hand; the boat struck a decent sized sea and took a roll to port.
I stuck out my left arm to avoid a fall and in the process my SS watchband contacted the nicely grounded port engine block.
The resulting arc spot welded the clasp of my watchband closed.
All concerns about the starboard engine not running vanished as I jammed my frying wrist into the bilge water. Removal of the watch involved breaking the spot weld with a screwdriver. I still have the scar from that encounter, and I've never worn a metal watchband since that day.
I don't recall "feeling" the 12vdc, but maybe the branding operations masked that sensation..........
Jim
PS: The Cat fired right up once I finished tightening the connection! But, it took me a little while to get back to it.
Never underestimate the value of a sharp pencil or good light.
In the big computer biz (where power supplies may be good for 100 amps), it's SOP to remove all jewelry before working on the beasts.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
I'd vote for that based on personal experience!
JimNever underestimate the value of a sharp pencil or good light.
I am convinced that 99.9% of the material out there about shock hazards has it's roots in the same, oversimplified, dated material. The devil, they say, is in the details.
In the simplest of terms, the body is controlled by tiny electrical impulses. Under the correct circumstances, I suspect you could kill someone with a watch battery - just get that battery to short out the part of the brain that tells the heart when to beat, and you've got a corpse in the making. Trust me on this one - BTDT, don't ask for the details.
Only 'in the making,' though. Such a person is electrocuted, but not dead - yet. There is still a very short window where you might be able to revive that person. And, in theory, all it takes are milliamps and millivolts.
Nature isn't stupid, though, and has built-in quite a bit of protection against electrical shock, through mechanisms that are still not completely understood. That's why we don't often hear of folks getting hurt by their 12v Malibu lights. Can, under the right circumstances, those lights hurt you? Absolutely; it's just pretty hard to create the 'right' circumstances.
Shock hazard isn't just about physiology. Far more folks are killed by 120v each year -even trained professionals- than are injured by 60,000v uninsulated power lines? This is because of the 'mental' element to risk; folks fear big, fat, high voltage wires, so everyone takes precautions. Folks are familiar with 120, feel comfortable around it - and get careless. Oops. It's sort of like all those idiots who get hurt playing with 'unloaded' guns.
The discussion also ignores secondary causes of injury. For example, a small shock results in your falling off the lader; the fall gets the blame for the injury- not the shock that caused the fall.
>Under the correct circumstances, I suspect you could kill someone with a watch battery - just get that battery to short out the part of the brain that tells the heart when to beat, and you've got a corpse in the making.No.The brain doesn't trigger the heart, it can influence parameters of the contractions, but originating signal is in the heart and it's self generating, basically like a leaky capacitor trigger with a reset. That's how people can be brain dead and still have a beating heart. Then there are multiple redundancies of multiple natural pacemaker sites with progressively slower rates, so if the signal doesn't get there in time, the next part of the heart fires on its own.Perhaps it's possible if you use a chopper circuit to step the voltage up then time a shock to the T-wave on an internal lead. I don't know if you could store charge enough on a capacitor faster than it would leak away.---mike...
I am well aware of the texts you've been reading, but those books over-simplify things a bit. Trust me, the heart and lungs CAN be shut down with the right zap to the brain.
Pretty daring for me to assert this? Maybe - but, as I said, I have some personal experience in this matter. In that incident, revival was successful. The incident was fully documented, the victim briefly hospitalized, etc.
Let's not dwell on the physiology, though. It's enough to underscore that even tiny amounts of electricity can hurt you. There is no 'safe' voltage or current.'
So, why does the electric code treat low (less than 50) voltages as though they were harmless? Well, look to the very first page for the answer; the electrical code is intended for the PRACTICAL safe use of electricity. That's still not the same as 'harmless,' or any reason to tempt fate.
Of course, I might be wrong ... after all, we've all known people who seemed intent on living a full life witout ever using their brains! :D
>Maybe - but, as I said, I have some personal experience in this matter. In that incident, revival was successful.Are you sure that the heart was shut down?My grandfather collapsed in a hospital and they found him on the floor. I was told by his *doctor* that he went into fibrillation and they "revived" him, but he had aspirated and never really made it out of the hospital. Knowing that he was ambulatory and monitored, I asked to see the ECG record at the time of the collapse, since I knew he would have been on a telemetry unit. No evidence of fibrillation, just a slow heart. He probably had a vagovasal response, his blood pressure dropped, and he essentially fainted. "Syncope" in medical terms.I can see how electrical stimulation can cause syncope, which may look like a heart stoppage. You can't feel a pulse when blood pressure floors. A study on EMTs has shown they miss a pulse more often than not on unconscious patients. I will agree that low voltages can kill. But a watch battery has high internal resistance. It's doubtful it could do much damage. A 12V car battery can weld metal across laid across its terminals. 500 cold cranking amps can do a lot of damage.But there are levels of electricity that are considered safe for a wide range of conditions. It's only if you get up close and personal with a sufficient number of particular cells that low-level electricity has any chance of doing any damage.By the way, related to another part of this thread: it wasn't the general discussion of topics on this thread that I was indicating was getting too detailed. It was the particulars of synchronized cardioversion vs. unsynchronized defibrillation for focal vs. re-entrant monomorphic ventricular tachycardia (and in comparison to ventricular fibrillation) and the relationship to ventricular repolarization vs. effects on atrial activation that I thought was exceeding the scope of this discussion and was straying far from the original post, but was the next step on that topic. And I wouldn't consider anyone poking around Fine Homebuilding a "dumb carpenter," which I've known a few and am sure they wouldn't be seen around these here parts.---mike...
Examination by responding emergency personnel, as well as further examination at the hospital, are quite clear on the point of cardiac arrest. That guy was shaking hand with St. Peter, when he was so rudely called back.
Circuit involved was 120v/20a. The breaker did not trip. A small burn at the fingertips and a blister on the temple (which came out the next day) indicate the path of the power.
> Far more folks are killed by 120v each year -even trained professionals- than are injured by 60,000v uninsulated power lines?I think that's also due to the simple fact that there are far more opportunities for someone to be shocked with 120V than any other source (greater than, say, 24 volts).
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
The issue is not whether or not voltage kills, but how it's delivered. The saying is meant to indicate that the amount of current you get is more important than the amount of voltage you get. A static shock in winter can be 20kV, but 20 mA can stop your breathing, which is a lower threshold than stopping your heart.It's actually more complicated than just that. Frequency is also important. We're pretty resistant, so to speak, to DC current and really resistant to high frequency current. We're most suspectible to frequencies in the 30 to 70 Hz range. (Note relationship to power frequencies used worldwide: 50 or 60 Hz.) A static shock is very short, meaning mainly high frequency - not a problem.(By the way, my main income is as a research engineer on external defibrillators for EMTs and hospitals. Craftsman style renovation assistance is on the side.)Also, it matters where the current goes. Current passing from one finger to the next one may hurt, but won't kill you. But current passing to fingers on opposite hands (passing near your heart along the way) can kill you. Between your right hand and left foot is the worst combination of limbs. I've zapped myself intentionally with 200 mA between electrodes on one leg without worrying. If working with live wires (not recommended), use one hand and keep your feet out of puddles.As mentioned, dry skin has high impedance, on the order of megohms. Wet skin reduces the impedance, and open skin even more so. Air has high impedance. Salt water (which is primarily what your blood is) is a conductor. Lightning looking for the lowest resistance to ground would prefer a standing hunk of salt water with a wet covering as opposed to continuing through the air.Additionally, timing of a shock is important. Delivering the full output of a defibrillator shock (about 2kV) across the chest won't harm anything if synchronized to the peak of the natural heart rhythm. Delay the shock by 100 msec and you have a really good chance of causing fibrillation, which is not the same as asystole. By the way, a true flat line on an ECG (asystole) that you see on TV cannot be restarted with a defibrillator. Defibrillators actually try to get the heart to stop, so that the body's natural pacemaker can take control. A defibrillator is sort of like a teacher at a playground yelling at all the kids to stop and line up, rather than going around asking a few kids at a time to get in line, then chasing some more. The heart in fibrillation is a bunch of heart cells all getting activated by their neighbors, rather than waiting for the coordinated signal to go. The shock restores order so the cells can get the right signal.Finally, while I'm on my soapbox in the middle of Suddent Cardiac Arrest Awareness Month, there's a relatively new 2-step recommendation from the American Heart Association for normal person CPR if you haven't been trained. If you see someone collapse and the person is completely unresponsive (not like drunk unresponsive, but absolutely nothing except perhaps an occasional gasp)1. call 911
2. press hard and fast in the center of the chest.Don't need mouth-to-mouth; don't need to count (though the beat for "Stayin' Alive" is actually close to the idea compression rate). You do need to push hard, about 2 inches down. Pushing less just jiggles the blood around and doesn't force it through the body. The chance of causing harm by following these rules is much less than the harm done by not doing anything. There's about a 10% drop in survival rate for every minute delay in CPR/defibrillation. If you wait for the ambulance to arrive...I don't know why the AHA has to put their info on another site but the link is: http://handsonlycpr.eisenberginc.com You can get there from heart.org, but it's hard to find now (was easier when the recommendation first came out).---mike...
Maybe you know the answer?
Have been told (but have not seen any schematics) that the newest generation of defibrillators can do a 'micro ekg' and time the defib pulse to the P or just after the T wave.
Anything to that??
Being that this is a construction forum, I won't discuss anything medical that is not pretty well established and/or published.
Being that this is a construction forum, I won't discuss anything medical that is not pretty well established and/or published.
Yeah, but like the Nat Enquirer sor some such yellow sheet says:
All the stuff ya gotta know<G>
"All the stuff ya gotta know<G> "Yeah,
Don't lick the battery
Don't pee on any fence with insulators
Don't stick body parts into light sockets
and above all else,
Don't call the tech help line until you check to be sure it is plugged in and turned on
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
And recall the 'darwin award special' !!!!!!
If your GF leaves you for another bloke, dont climb the HV tower to look at the sunset while drinking 5 of a sixpack and then take a whiz out over the 345kV line!
Supposedly true story, have not 'snoped it' though.
> Don't call the tech help line until you check to be sure it is plugged in and turned onHow you gonna do that if you don't stick your finger in the light socket?
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
re; established:
Jan 2009 issue of Cardiac Science says defib during QRS is now "well established".
Pretty sure one would want to avoid defib during the T-wave, so why not at P??
>Jan 2009 issue of Cardiac Science says defib during QRS is now "well established".
>
>Pretty sure one would want to avoid defib during the T-wave, so why not at P?? The terminology is wrong, defibrillation is by standard definition unsynchronized, and technically, you can't de-fibrillate something that's not fibrillating (VTach). There are issues of focal vs. re-entrant tachycardia. In a crisis, pumping blood to the body is more important than pumping to the next chamber, so atria are not considered. And I'm sure nobody else is getting any of this discussion, so I'm sorry, but that's my last word on these details in this thread. :-)---mike...
" I'm sure nobody else is getting any of this discussion, so I'm sorry, but that's my last word on these details in this thread. :-)"Actrually...I don't know all the terminology, but it is fascinating to me. TYhis is not just a bunch of dumb carpenters here, calvin's self proclamation to non-fame aside, and this is stimulating information.I had a racing heart and solved with radiofrequency ablation. I also have some interest in mind/body connections...Keep talking.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
not just a bunch of dumb carpenters here
Ya know, got a bee sting 2 weeks ago.
However, memory is getting so slow, when I got stung, but remembered somebody telling us here on BT about a 'cure' for preventing swelling that i knew I could apply within a few minutes.
However, took me a half hour to remember that the 'cure' was a 20 mA electrical shock applied to the area. By the time I remembered that tidbit it had already started to swell even after trying the snakebite type 'remedy'. After 1/2 hour, the shock from a 10 kV , 10 mA current limited supply did nothing to stop further swelling. And that was after I thought the 'cure' was either methyl chloride or HCl, both of which I'd applied with no effect except a slight burn.
Oh well, I WILL remember it next time, as do have a 10 kV supply handy in the barn lab. Then will see if it works. <G>
junkhound,That was my cure but the shock came from magneto. I had no volts or amps specified. Explanation I read was that it changed the polarity of the venom, cis to trans or vice versa. Wonder if there is a difference between ac-dc?There is a patent on this but not mine.KK
I get it - had a lot of conversations w/ Cardiologist about how things work. After all, I'm host to that dumb box of sand that my life depends upon.DonDon Reinhard
The Glass Masterworks
"If it scratches, I etch it!"
The new Defib does do some monitoring before it will shock. If the person's heart is working it will not go. I am not sure if it is smart enough to time the shock tho.
The new "automated external defibrillators" contain an EKG circuit that recognizes fibrillation and only applies the shock if its present. Certainly wouldn't be hard to somehow time the pulse, given that (only I'm not sure what you time to if the heart's fibrillating).
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
I am host to a Medtronics pace maker. Had it for about 6 yrs & on verge of new battery. That poor piece of machinery goes everywhere I go & does everything I do whether it wants to or not.I've taken two shocks from line voltage right hand to left hand. Recorded the time of the events & reported them the next time I had the memory downloaded. Not a single anomaly reported in the memory. In the "Not Fun" Dept - had my ventricular lead break & PM went into its fail safe mode of using my body for its return electrical path. I had a lot of discomfort in the cavity where the PM was located. Principally it was localized muscle spasms.My failure had two cardiologists, their nurses, two Medtronics Reps, one electrical engineer (Me) & the Medtronics home office stumped for weeks trying to figure out what happened to match the diagnostics in the PM. Finally, a routine chest X-Ray showed the parted lead that was hidden in several other X-Rays. Got a new lead implanted to fix problem.DonDon Reinhard
The Glass Masterworks
"If it scratches, I etch it!"
24 volts and lots of amps with a good ground is about all I can handle. I have experimented with 24 volt batteries. grab the + and - each with a pair of non insulated pliers and I doubt you can hold onto them. I have received higher voltages but with poor grounds or little current and that is the reason I can tell about it.
Virginbuild
As others have said, it's very likely that by "low voltage" the article (or the person quoted for the article) meant a voltage less than several thousand volts. However, there are cases where people have been electrocuted with well under 100 volts. Even with reasonably dry skin and no "extenuating circumstances", I believe there are cases of electrocution documented down to about 25 volts, and people undergoing surgery or in other medical settings have been electrocuted with less than a volt.
Really depends on a lot of factors when determining voltage that will electrocute you. Intact, dry skin has a pretty high impedance. Kinda tough to cram enough current through that at extremely low voltages - like under 24. But - if you have an open wound, you can probably do a pretty good job w/ 6 volts if the source has a low enough internal impedance. Once I got a heck of a wallop through an open, oozing abrasion from a low (sub 110V) voltage. Human body fluids are pretty well filled w/ ionized electrolytes - like K, Na, Ca & lotsa Cl. Another time, in an EE Lab in college, I was working on an experiment atop a stainless steel table that wasn't grounded. System had a high impedance leak. Where my forearm rested on edge of table, I felt like I was on fire. Abrasion was oozing & made a great low impedance path into me.Also, if you are all sweaty your skin impedance drops dramatically. The ions in sweat are great conductors of electricity.I read the story as a student working on a lamp - most likely connected to 110 V. DonDon Reinhard
The Glass Masterworks
"If it scratches, I etch it!"
Despite all of the discussion, this wasn't low voltage in the context we think about with houses. My door bell transformer is "low voltage," as are my stereo speaker and telephone lines. I never worry about getting shocked working on them while they might be live. I think it's context, as the first posters noted.
"is it possible to be electrocuted to death from "low voltage electrocution?""
FWIW it is impossible to be electrocuted "to death" because the person is already dead from the electrocution.
William the Geezer, the sequel to Billy the Kid - Shoe
As far as I know, ther are two ways to die from electrocution.
1. You get cooked. That's right, there's enough power dissipated in your tissue that it heats up and "cooks".
2. The other way you might die is if the gases dissolved in your blood are disassociated (liberated). The gases become bubbles and can cause clots. A clot reaching your heart means a heart attack, hence, you die. This is the sneaky way to die from electrocution because it can come fairly long (perhaps an hour) after the actual incident.
I find it senseless to say it's the amps that get you. Your body has an impedance characteristic. Given the right voltage, the current will flow. Without the right voltage, the current won't flow. Both are necessary to kill.
I would also worry about anything over 20 V. Voltages higher than that can ionize stuff in your body (under the right conditions).
I also worry far more about DC than AC. DC makes your muscles clench. You grab it and cannot let go or fall. With AC, your muscles twitch and you can probably drop or let go.
Do not forget ventricular fibrillation, which is the basic cause of electrocution. Typical studies find that over 90% are attributable to arrhythmia.
AFAIK, your #2 is exceedingly rare 'cause', if actually a cause and not a effect. Bubble formation post mortem is attributed primarily to the accumulation of CO2, derived from residual cellular respiration after death.
BTW, the lowest voltage documented to have caused electrocution is 18 Vac.
BTW2, you can get a BIG jolt (3A at 3kV) and survive if fortunate enough that the jolt is less than about 3/4 of a second and does not occur during your heart's T wave.
If we're talking measurements, let's not forget the ohm which is the measurement of resistance from one point to another.Lotta ohms in this forum at times.
"Lotta ohms in this forum at times."Only when measured betweem 2 points on the melon shapped appendage on the top of the boddy.
.
William the Geezer, the sequel to Billy the Kid - Shoe
Ohm -- that's my mantra.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
While reading your post and all of the replies, brought to mind the tasers that the police sometime use. We are talking about thousands of volts aren't we. How many or few amps are we talking about here.
Micro amps, but they still kill a guy with a taser now and then.
Micro amps
Yeah, about 4000 to 5K of them there mircoamps, on average.