Which is More Dangerous: AC or DC?

yes dc is more dangerous as it's continuosly /never cross to zero.

DC never Cross zero, but how about the peak voltage that is 1.41 times of its equivalent DC.

Either one can render you permanently dead, if not used/handled properly.

Like the guy said, "A Piper Cub is the safest plane in the world. It can just barely kill you".

They are both dangerous.

Heart muscles beat on their own when no external signal is present. Cardiac cells are different than any other muscle cell. A defibrillator causes complete discharge all all muscle cells, allowing them to restart in unison. The only signal to the heart is a rate signal. the heart will beat just fine without a brain at all. Now breathing is another matter.

It usually takes less AC current to fibrillate a heart than DC.

Hi everybody here,

in fact, there are both dangerous, but to decide which one is more dangerous and can injure or even kill, you keep in mid that that depends on the insulation resistance of the body that the current passes through it..... also have in mind the term "dangerous" stands for a high current passing through your body regardless of the kind of the current whether it's DC or AC"..........................

Rgds,,,

To my understanding, it is not ac or dc but energy- no current as we know it passes thru the body(ie-electrons)- but the energy in the electrical conductor, when in good contact with the human/animal skin(being far greater than the energy needed to run the human/animal body) tranmits thru the sodium & potassium atoms present in the human blood- it is this excess energy at vital organs that disrupts & kills.

As my direct experience has shown.

It's all about the "Potential".

The greater the voltage the greater the potential there is to maim or permanantly kill.

Irrespective if its AC or DC.

Current plays a part too, which is why residual current circuit breakers are so important.

It's not the voltage that kills it's the amps.

I've always been told that the 110v AC outlet in our homes is the most dangerous because people underestimate its potential.

My brother was zapped with 16,400v, was thrown back and spent two weeks in the hospital being de-electrified. He has a scar next to his belly button that looks like a second outie belly button.

He was working on the relays that control the lights on an airfield runway.

We've been over this before...

See http://cr4.globalspec.com/thread/3212

60 Hz AC is more likely to cause ventricular fibrillation than DC.

"60 Hz AC is more likely to cause ventricular fibrillation than DC."

Hi,

The above statement is.................................................. so, so apropos for the thread.

Let's talk some volts and amps too. 200AMPS at 415V will a do number on you, AC or DC.

Anyway, I assume that you are talking 120V and some amps (AC) to stop the heart.

Once you pass the threshold, AC or DC it DM. (doesn't matter) You're still gonna die!

The current needed to throw the heart out of rhythm is about 2 milliamps. That's all. Because of the composition of the blood vs tissue, the current preferentially follows the large blood vessels, ie, through the heart, disrupting the pacemaker.

The heartbeat is like walking. Each step prepares for the next. The electrical impulse sweeps through the heart muscle in a coordinated way, like a wave. When the contraction is over, the muscle is all set up and ready for the next beat. Any substantial disruption of that wave, and the whole thing goes out of synch.

DB

Mister Dingdong here, in a moment of stupidity, deliberately electrocuted himself with 240 Vac in an electrical-engineering lab just to see what it was like. (I'd read the night before that the resistance of human skin is a one megohm ... and 240 volts divided by a million ohms gives only 240 micro-amps, a small current, right? It turns out that it doesn't take a whole lot to drive signals up and dopwn one's nervous system ...). I placed the palms of my two hands on the crew-lugs of a small transformer and ...

Well, what happened is that I was completely, but COMPLETELY, anesthetized from the breast up. I couldn't feel a thing ... you could've hit me with a hammer and I'd not have known. Also, my heart was pounding at a furious rate in my ears and I was spacy for a few minutes. No pain, just discomfort.

Uuummm ... I won't be doing THAT again. DZ

Shocking thing to do.

ps it will take a few days to fully recover, been there done that ( a few times)

I too have personally experienced the shocking (pun intended) result of misjudging and/or mishandling electricity.

I have to agree with all the comments here about the CURRENT being the dangerous aspect. VOLTAGE is not the deadly component, but it does hurt more. The heat, literally and figuratively, is in the voltage.

I have been hit by discharging capacitors and 'loaded' power supplies on many occasions. The higher voltage, the higher the pain.

I Could not move my right arm for nearly 2 days and was out cold for about 30 seconds after taking 120,000V @ 5 amps, straight through the chest. My left arm was the conduit to the ground. I took about a 30 minute break and went back to work. One handed.

I have been 'hit' by 240v several times (60Hz, 30A). I hurt like hell for about 15 seconds each time and resulted in burns on my fingers once.

I can actually hold on, with all current passing through my hand, to 120V 15A for several seconds with no ill effects.

One of my best friends survived 400,000 volts AND the subsequent 120ft. fall from a transmission tower.

I have also personally witnessed someone die on a pole from that same 120V that I can 'handle'.

My point, really, is that it can ALL be dangerous depending on the circumstances.

I agree.

As I had stated in my original response that started this off topic thread.

It all depends on the circumstances.

Measuring on my own body resistance, even wet, I could not get any where near the values you mentioned, they were far, far higher.....

......can some other people make some measurements please???

I just washed my hands about 5 minutes ago, then time to dry. On a B&K DMM, grasping the tip (about 8mm of metal exposed) of one probe between thumb and forefinger of each hand and squeezing as hard as I can: On a 4MΩ scale, it briefly indicates 3.something, then goes off scale. On the 40MΩ scale it indicates 5.0-5.3MΩ for a few seconds, then starts to rise.

9AM my time. for whatever that's worth.

Dick

You are a Pal!! Many thanks and well done, you seem to have a similar resistance to me!!!!

I wonder how many more there are with similar readings?

You are still ok. But need more drinks. LOL. D

I was supprised to have read in an official OH & S review that skin resistance decreases as voltage increases. Michael - Australia

I agree entirely with you (except that up to now I haven't had silver in/on my skin!).

It is next to impossible for the body of a (normal) person to get the skin resistance so low that any current large enough to kill someone will flow....a low skin resistance is in the order of 500,000 Ohms or so......usually my skin resistance dry is above 5.5 Meg Ohms....

Tested using a DVM with a 9 volt battery, by pressing my forefinger and thumb of both hands onto the test probes.

I also made both hands wet and measured again, I got slightly under 500,000 Ohms....

Using simple Ohm's Law, this will give at worst a current of around 0.00024 Amps. Nowhere near enough to feel or to damage anyone.....even if their skin resistance is a factor of 10 lower......completely harmless.

Now if there was open heart surgery and 12 volts was applied directly to the heart, maybe an effect......I don't know.

Defibrillators usually have far higher voltages to work properly so a few microamps are unlikely to have any effects...they need the high voltage because of the high resistance of a normal person's skin.....

Defibrillators are are dangerous to people's hearts that are working normally......upto 3000VDC I am lead to believe.

Here is a demonstration using a cap from such a unit, rated at 3000VDC:-

http://www.youtube.com/watch?v=BqgxQG1PyfM

This will "Start" a heart, or probably stop one too.......

Drinking the battery acid, or exploding the gas or eating the lead plates could of course kill someone....or having it dropped on their head from a great height are all possible ways to die from a 12 volt car battery.....maybe there are a few more methods....electrocution, if possible, must be WAY down the list!!!

A tiny bit of a misread there. I said sliver, not silver, although I have perforated my skin at least once with a silver sliver. Sounds like the beginning of a tongue-twister...

Although my main formal training was in electronics, I'm also a machinist, so I rather commonly have bits of metal stuck in my skin; and sometimes I don't even realize the sliver is there. On several occasions, I have discovered the presence of such a sliver when I felt a shock from 5 or 6 Volts. Having a metallic sliver penetrate the skin of a finger makes that point have roughly the same sensitivity as the tongue with no sliver.

It's 9:30 PM, so I tried measuring my resistance again: This time it was 1.2-1.4MΩ on dry skin, washed a little over an hour ago. Then I wet both fingers and thumbs with wine (2006 Treana Red, from Paso Robles, CA-Excellent-a Christmas gift, so I don't know the price), and I was able to consistently get the resistance down to 150kΩ. Actually, I think I saw 20kΩ briefly, but was unable to repeat it. I just started the test over, and was unable to get it to stay below 350k on the 4MΩ scale. Maybe I need to lubricate the interior a bit more...

LOL!

Thanks for the "sliver" of a correction......

Try actually measuring the human body resistance on a few different people and in different weather, and after different levels of activity. I've done that hundreds of times in my science classes, and the body resistance can easily vary by a factor of 100. Once you begin to get shocked, you will probably perspire, which can lower your body resistance a great deal.

I happen to be an oily-skinned person. I believe that means I have higher than usual skin resistance, so I probably don't feel shock as intensely as others. I've been shocked several times by 208 & 220VAC, and once by 480 (one fiber of a stranded wire poking through the electrical tape). In all cases I let out a yelp and pulled back very quickly. On the other hand, as a child of 10 or so, I was thrown across a small room by 120VAC (wet plaster on the floor).

for the same person with may the same resistivity, 60Hz AC will give chances for you to remove your hand 120 time a second. but DC will elctrolyse your body chemicals, which may lead to damage. my practical experiance with my right hand touching 120V ac both the legs on ground just gave me a kick i could withdraw my hand quickly (as it was not entangled) i had numbness for some time. but with battery array of 120volt DC, i had a nasty shock and my fingre tip got burnt (first phalange of index finger, luckily finger not entangled) turned blue in colour and it took almost 10days for the colour to get cleared and numbness to go off. so in my openion DC is more lethal than AC

Mr. Edison and Mr. Westinghouse's arguments on this very subject are legendary. You may want to consult their biographies.

There was a neat play written on this controversy, A Peek Into the Twentieth Century. I saw it in a preliminary type of performance, and I don't know if it ever made prime time. Edison was a DC partisan, and he railed at "the executioner's current" (i.e., AC in the first electric chair at Sing Sing). A pivotal character in the play was the first person slated to be so executed. He didn't care about the mere dying so much as he was concerned not to be disfigured (or totally toasted) in the process. The play was presented brilliantly by the Seattle Rep in the early 1990s.

Let me be direct and rectify the current phase of this conversation by proposing an alternating, yet reactive switch to a grounded line of thought. "Touch that and you could be dead in your shorts"!

You said:-

"I know that DC has more rms value and no natural current zero"

Well I don't either know or understand that sentence, perhaps you would be so kind as to explain that in more detail to that EEs can understand fully.......thanks in advance.

By the way, I am of the opinion, through years of working on 220VDC, 230VAC, 380VAC 3 Phase, 115VAC and 440VAC 3 Phase.....that DC at 220VDC (or less) is most unlikely to kill anyone. I have had probably 1000s of 220VDC shocks.....no real importance noted on any of them.....we even searched for earths on circuits with wet fingers in the fuse box.....

The worst accident I ever witnessed was a RN (idiotic) colleague, who dropped an uninsulated long screwdriver over the main buss bars of an MSSS of a DC 200VDC 20,000 amp Generator on an Aircraft carrier in about 1965, with his bare hands......he got severely burnt hands and was blind for a few days from the Arc, but recovered fully in all respects, but with highly (shocking?) pink skin on both hands......

I could believe that it might be possible to get a burn under some other circumstances (which I have personally never ever had or seen) from DC.....thats all....

I have had a few shocks from both 440VAC 3 phase 115VAC and 230VAC single phase. The 440VAC was completely deadly, the brain goes into stop mode for some seconds, I got shocked between both my hands (NOT from one hand to the other!! Important!) and my Butt, so the path was NOT via my heart, but it was horrendous...I managed NEVER to repeat it again, once was enough....lucky, lucky....

The 220VAC shocks were not pleasant either, and still far worse than the DC shocks though. 115VAC is hardly worth mentioning, but has killed people also....

By the way, AC of the same stated voltage has far higher peaks than the equivalent DC voltage....the comparison is that both will do the "same amount of work".....due to the "peaks and the troughs" you need a higher peak voltage with AC than DC....its as simple as that.....

I personally believe that the DC causes the muscles to pull in and the arm muscles being stronger, pull the hand away from the shock as they are stronger than the finger muscles that might "hold onto" something with DC on it. Though I must say that I have never "grasped" ANYTHING with power on it, always it was just a fingertip.....

AC on the other hand "paralyzes" all the affected muscles, I have experienced that many times and just been lucky I guess.

This is against all the advice in most textbooks (not RN ones by the way!!), but I do not believe that many Authors have actually "tested" the subject as fully as I have!!! They just repeat what they have read!!!! Wrongly of course.....

For our 230 V AC, the peak voltage V_peak is therefore , which is about 325 V.

You can read this and other important data at:-

http://en.wikipedia.org/wiki/Alternating_current

To check voltage, lick your fingers and touch them to an electrical source. The distance you bounce is proportional to the voltage. This is called a "digital voltmeter," albeit a bit crude.

LOL!

and

OUCH!

THIS IS WHAT YOU SHOULD KNOW:

It is indeed CURRENT and relatively related to it - The applied voltage.

There are 3 important tracks to where CURRENT appears to be deadly:

1. General passage of the current through the body, which goes through the skin into our mass, that has a high volume of water and is relatively conductive.

This current can flow from the touching point to the ground, or to a second touching point e.g. to a different potential or phase.

Skin type: dry or moist give more resistance or less resistance.

I.e. dry skin type can take more VOLTAGE, as by Ohms Law.

MUSCLES ALWAYS CONTRACT WITH ELECTRICAL CURRENT - that means: If you hold on to a wire your grip becomes firm and uncontrollable, and you will not be able to break loose when the current is too high.

The first effect occurs within milliamps (1/1000 th of 1 Amp).

for freaks:

IF YOU LIKE TO FEEL POWER DO IT WITH THE BACK SIDE OF YOUR FINGERS - The muscles contract and will free you - AWAY FROM THE CABLE.

The SECOND phase (OF ELECTROCUTION) is breakthrough the skin, with burns and much higher CURRENTS- parralise your whole muscular system. Burning tissues OCCUR and surviver's have limbs AMPUTATED to avoid further worse. 2. Electrocution of the brain (crane) If the current enter the body this way, the whole command of the body can be taken out. Your position relative to the power will be determining Life or death. 3. Internal Damage: vital body functions stop Heart beat - Muscles get overstressed and accumulate acids - WHEN ELECTROCUTED For LONGER THAN 2 MINUTES - sometimes people feel good and die 2- 3 days later. THIS IS BECAUSE OF KIDNEY FAILURE - The kidneys cannot eliminate all the generated by- products in the water household and blood stream. GO TO A HOSPITAL IMMEDIATELY - it can save your life. I might not have the correct values but we are able to feel currents from 40 microamperes - yes some people feel a current with a 12 volts battery.

Try to lick a 1,5 volts battery between - and +. This proves the wet skin theory to be right too.

42 V can be already deadly in some cases.

People are no rectifiers - AC and DC might "feel" a different sensation but are both equally dangerous.

I don't completely disagree with everything, but you do not appear to have experienced shocks from high voltages at all, you are speaking as though you have just read from text books on the subject....don't be upset, this is my experience of most people who speak on this subject......Most textbooks are wrong......RN text books say exactly the opposite of what the other Authors say, I wonder why????

Believe me, AC shocks are worse for the same value of given voltage......

Also, which idiot "grasps" a cable, anyone with the tiniest modicum of intelligence will touch it first with a fingertip ONLY!!!! No chance of being "held" on......perhaps the mentality of the Darwin Awards website breaks though here!!!! Only the dummies die because they "grasp" a cable that may or may not have voltage on it!!!!

I have (sadly) first hand experience, in some cases many, many times of electric shocks, as I previously mentioned. Earth faults on 220VDC on RN ships are searched for with two fingers after removing both fuses to a circuit (correctly done with a test lamp, but if you haven't got one handy?), by applying the finger over each fuse position in turn.

Two 40 watt 220 volt lamps are fitted between + and -, with a middle connection to ground, so if an earth is present on either the + or - side, a voltage will only be felt when going over the fuse position of that polarity.

(I forgot to mention that all circuits are fused twice, once in the + and once in the - lines. Standard RN procedure for all circuits.)

Here is a circuit diagram:-

The earth lamps are fitted in each fuse box and can be activated with a switch (not shown here).

I sincerely speak from many years experienece "first hand" not from Text books, that makes a great deal of difference to my mind.........

In addition to the textbooks and the movies, part of the higher education in safety engineering in your European Universities - electricity - they also rolled in a talking person (body with only one arm left, after amputation -Antwerp 1996).

His 2 friends died in the same electricity accident.

I have seen fingertip feelers too that had no finger left anymore. As safety engineer in a 3500 men high risk industry I have been confronted with both AC and DC. And I have felt electricity everywhere, from small warnings to a little too long exposure with the weeks muscle pain afterwards. If you touch a flexible cable and pull it with the fingertip - the muscle bends the finger - towards the rest of your hand -(And your arm follows) you can get electrocuted. IF YOU WORK ON THE OUTSIDE - your flexor (bending) muscles are much stronger!!!!!

I did not discuss AC or DC - I said both can be deadly. PLEASE TAKE THE ADVISE IN MY POST. I am a in the field man.

I still feel that you are missing the point, the question remains still as "Which is More Dangerous: AC or DC?"....not advice on how to avoid shocks (which are still needed of course, but doesn't address the question!)

I still believe that AC "locks" muscles (been there, done that and NOT got the T-Shirt!) and DC causes them to contract, but as long as you don't "Grab" the conductor in the first place (only complete idiots will do that!), you have a far better than even chance of not being "connected" with DC.....for similar levels of voltage.......high voltages bring the possibility of bad burns as well of course, I do not consider 220 VDC to be high, rather more like medium....

Few people who work with electricity today have had "exposure" to both AC & DC in comparable voltages to house voltages, other than Navy service personnel of my vintage & before I believe.....in the USA I believe the USN had AC ships even before we in the RN did, we started in the mid 50's with AC ships......they were still in use when I joined in '63, but many older DC ships were still around.....

Modern electricians have mostly AC experience, few have worked on DC and the ones that have, have worked only on higher voltages of DC......3-6000 VDC for example is used sometimes for electric trains I am informed (I am no expert).

Where can you find 115 or 230 volts DC nowadays in large (ampage) amounts???? I am sure there are places, but I personally only know of ships....perhaps someone knows of other possible places......Please post.

I have been working with DC in

Paper coating and fabrication. SCOTT.

Reliance DC controllers with DC motors. Once you have web width of 8', the motors are 30- 60 kW.

The company where we used it stopped in the 80's.

The motors had a controlling range between 10- 500 VDC, all with tacho-generators for synchronization.

The B1 coater 200 m long - 300m/min with flying splice had 6 DC synchro motors and handled paper rolls of 6 metric tons. (I am talking of the mid 70's)

Andy, I don't know what is the most dangerous and I am too old to go on experimenting on myself.

I have received many licks from the old tube amplifiers and they hurt too, and that is DC.

Pulsating DC in small amplitudes and varying modulation is used in muscle recovery therapy.

AC hurts more if you ask me and I think it is because of the frequency: our muscles are to slow to follow and get more uncontrollable pulses without a build up as in DC and that pain is more vibrating like your modern electric shaver.

On the other hand the available current is the measure. I have been exposed many times on neon AC with limits of 10-15-20 mA. These gave a feeling, not a real shock and even the 10.000 Volts with dry weather was bearable. We need more input here, because IMHO many posts are dubious.

I liked your post, particularly the sentence:-

AC hurts more if you ask me and I think it is because of the frequency: our muscles are to slow to follow and get more uncontrollable pulses without a build up as in DC and that pain is more vibrating like your modern electric shaver.

That supports my experience and thoughts as well, the muscles cannot react fast enough and simply just "lock up or vibrate" where they are....

But do remember that the DC level in monitors and TVs with Tubes is Far Far higher than house current voltages in either the USA or Europe......that is an important point that many forget. You must always compare apples with apples.....luckily, the voltages in such units have low ampage, which makes such a shock painful (often with burn) but less dangerous!(notice please that I say "LESS"!!!!)

I've gotten careless with CRTs several times, and did not enjoy any of those times! The first time, around 1958, The TV had been unplugged for a month (dry California summer), but it still got me 'good'.

I also got careless once while pruning an oak tree and just barely touched a 12kV power line with the branch I had just cut. It was a dry, but not dead, branch that was obviously closer to the line than I realized. The hand grasping the branch by the bark felt nothing. The other hand was lifting with the palm in contact with the cut, and I felt a tingle - just enough to make me pull that hand away quickly.and switch directions with the other hand. I did not attempt to determine the resistance of the branch, or otherwise find out the current involved.

Having observed the spark that could be generated (around a cm long for a large fraction of a second) by a 300V battery (from a tube-type portable radio) by touching the two leads and then drawing them apart, I have always assumed that DC was more dangerous, with no real scientific basis.

PS:
' "Debugging computer code is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as you possibly can, you are, by definition, not smart enough to debug it." – Brian W. Kernighan' I guess that means I was never as clever as I could have been in writing code, because I have always debugged my own code...

Your comment:-

I guess that means I was never as clever as I could have been in writing code, because I have always debugged my own code...

...just means that you were not "stretching" yourself while working!!!

"DC level in monitors and TVs with Tubes is Far Far higher than house current voltages in either the USA or Europe......that is an important point that many forget. You must always compare apples with apples.....luckily, the voltages in such units have low amperage, which makes such a shock painful (often with burn) but less dangerous!"

With regards to the above comment referring to "less dangerous." If an audio amplifier has +400 VDC stored in a 750uF capacitor; that's a lot of energy in comparison to an amplifier with +400 VDC stored in a 40uF capacitor. I sure wouldn't want to grab onto either power source, especially the one with a 750uF (two 1500uF caps in series). I have 750uF in a power supply I'm breadboarding and yes, I'm real careful. So it's not just voltages at low amps, you've also got to consider stored energy of a circuit.

I built a small flyback power supply that uses three separate secondaries, each providing 133 VDC, or 400 VDC, total. With a 67KHz switching frequency, I only need a small capacitor at the output; nice thing about switchers: less stored energy requirements.

We were talking about monitors/TVs, there you can get a really "unfriendly" belt (even weeks later after switching off!)and often a small painful burn that takes a long time to heal, but generally there little energy and a normally fit person with live to swear and curse!

Luckily most monitors nowadays are LCD or similar and this danger is already gone.

What percentage of TVs have tubes today I cannot say, but there are many around and they are getting old and dirty inside, that makes them even more dangerous to work in/on!!

You are talking about other equipment with serious internal power levels, again you are not comparing "apples with apples" I feel!

Using your explanation I could say grabbing a 380 volt mains will also give a hefty belt!!!!! But its a silly comparison......not comparing like with like.......I specifically mention monitors with CRTs....

Have agreat day.

I was picking up on a subliminal theme that may have inferred consumer products are not as dangerous. It's a given that whether AC or DC is more dangerous is a question loaded with variables; definitely an "apples and oranges" question as you very well state. It's kinda like asking which way am I more likely to be killed: Walking off the 20 foot deck of my house or walking in front of a car going 10 miles per hour. Answer is obvious, you can be killed either way if the conditions are right. One thing to be gained from the overall AC/DC discussion is to provide some experiences, such as how to survive working around high voltages.

My personal survival method of working with lethal voltages is to 1) keep one hand in the pocket and 2) don't work on high voltage stuff after 2:00 PM during a workday. For me, 2:00PM is when I'm not mentally alert as I would like to be. As anyone knows that has designed power supplies, it also means you could be blowing up a lot of parts in the process. So you have your hands around power electronics for a good amount of time during the development of a power supply.

A funny story: After normal work hours the President of Teledyne Systems would wander into the power supply lab to shoot the bull. One day as the Pres was chatting an engineer was working on a power supply and a big "BANG" came from his direction. The Pres looked over and said, "A reversed tantalum?" We all laughed that the Pres actually knew something about power supplies.

I agree with both of your numbered points. I suspect that that means that you (like me) are a 'morning person'.

For me, a nap and/or a walk help. I think it was in the latest SWA's 'Spirit' magazine that I saw an article where some research showed people 20% 'smarter' at 5PM if they took a nap...

Yes, definitely a "morning" person. All the good ideas arrive between showering in the morning to about 10AM; then it's downhill thereafter. It's amazing how many design solutions just "popped" into my mind while in the shower. A 20 minute nap after lunch is good, helps me make it through the rest of the day. The nap might be mandatory depending what you were drinking at lunch time <g>. After eating a burrito and drinking peach margaritas at a great Los Angeles Mexican restaurant, I'd close my office door and lay on the thin carpeted floor for about twenty minutes. It's amazing what twenty minutes will do!

Another high voltage safety thing was having at least two people present inside of the high voltage lab when anyone was working with high voltages. Sounds like a good idea, but this "rule" was never followed.

Why do I get the feeling we've been "trolled"??

Considering that the execution of an individual by electrical current uses AC vs. DC, AC is, as has been proven, more lethal; they are both equally dangerous, however.

...but do not ignore the fact that such executions use a voltage far, far higher than normal house voltage......or did you simply forget this point?

Also they (the person to be electrocuted) is strapped in and has electrodes with sponges, wet with salt water to improve the conductivity of the skin at that point etc etc....a current of at least 5 amps seems to be the preferred value, which will be difficult to achieve unless the skin resistance is somehow dramatically reduced (the salt water sponges for example!), plus large areas of contact as well.....

At least double European house voltage is the lowest "killing" voltage used..... Also applied for 30 seconds or more!!!!

The comment of "1400 volts for 17 seconds was insufficient" says it all for me and supports my experiences that 220VDC (or AC for that matter) for a split second is unlike to kill someone unless they are extremely sensitive to shocks, have a pacemaker or similar, extremely low skin resistance, shock is directly over heart etc etc etc.....as normal skin resistance will preclude a killing current to be developed....

See here:-

http://hypertextbook.com/facts/NancyRyan.shtml

I trust that many others will find the following very interesting, just as I did:-

During my younger years, I was involved with both the repair and then later with the restoration of pre-war televisions. My biggest "kick" was from a 1957 RCA color TV (CTC5 chassis) with a metal bell (cone shape) picture tube (21AXP22A). My dad used this set to learn color television circuit theory. I was about 16 years old as I was adjusting the yoke and I somehow came in contact with the bell of the picture tube which operated around 20KV or so. I went sailing about five or so feet backwards and landed on my butt. That was my worst electrical shock experience. The DC supply voltage of old tube hi-fi amps can provide quite a nasty jolt, too.

In the past, I've designed high voltage, switching power supplies for multi Kilo-Watt, TWT transmitter tubes. They really scared me. Never got a shock from a TWT power supply and that's a good thing. They have both a high voltage (4kV range) and high operating current (amps+) output. The power supply input voltage was 3-phase, 208VAC, 400Hz ... that too could do a lot of damage to the body. I recall once a ball of molten copper dancing along the floor, caused by an input power short. There's a "one-hand in the pocket" rule when working around high voltages. I used this rule as much as possible.

Trust me,

The body's resistance is considered to be approximately 50 ohms when the skin resistance is broken down by a defibrillator or anything else that has enough voltage to cause this breakdown. We used this calculation do compute the surge current at 400 joules ( max on the units I worked on at the time). That translated to >35 amps during the approximately 5 ms that it took to discharge.

You are right about that. Under the skin we are a lot of water for no more than 3 dollar value.

You will need your 400 joules to reach the heart zone because a lot of this load disappears in the water mass.

In most of the posts the skin has been indicated as a relatively good electrical insulator.

Most of the posters feel good in their skin, I assume.

Good Post with humour, it does not get any better than that to my mind!!!

Here is a chart that shows dangerous levels of milli-amps and how they change over frequency and the male female differences. I can email this to anyone who needs a version that is easier to read.

I will send you my email address, thanks in advance.

So what the above chart shows is that AC is more dangerous than DC at frequencies up to about 10 Kilohertz, then they are both about equally dangerous at equal amperage levels.

It shows for an average person the perception levels, the lock-on (loss of muscle control) threshold and the I'm sorry for you threshold by frequency.

Note the difference for men and women. The average women can be hurt by a lower amount of current than a man because of the differences in the subcutaneous skin makeup.

Please note this is for the average person. You may be easier or more difficult to shock depending on your personal body chemistry. The US navy has a case of a stupid person being killed by 9vdc so don't assume it can't hurt you.

Your chart confirms completely my own (mostly unwished for) research over the years that DC is far less dangerous than AC......for the same voltage/current levels......

So many textbooks are completely wrong on this subject, and many people (here on CR4 too!) quote from the same textbooks, I have always quoted from personal experience only......

Many Many thanks. Vindicated at last.

The chart is really really great.