Big Clive video: 10mA hand to hand electric shocks - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 20, 2019, 12:27:45 am
content: I haven't watched it all, but

author: Mr.B
author_rank: Unknown
timestamp: March 20, 2019, 12:53:36 am
content: Fark! My heart was racing just watching it.That is simply borderline stupidity.I hope nobody out there in copycat land watches that one.

author: amyk
author_rank: Super Contributor
timestamp: March 20, 2019, 01:18:21 am
content: This is not his first time:

author: Mr.B
author_rank: Unknown
timestamp: March 20, 2019, 01:28:54 am
content: Deathwish?

author: tautech
author_rank: Super Contributor
timestamp: March 20, 2019, 02:29:19 am
content: Quote from: Mr.B on March 20, 2019, 01:28:54 amProbably and also the handle of a dear departed member.https://www.eevblog.com/forum/profile/?u=107683

author: Psi
author_rank: Super Contributor
timestamp: March 20, 2019, 06:13:47 am
content: Come on, 10mA isn't "safe" but it's far from lethal except in very specific circumstances.If he was doing that at or above 30mA i would be very concerned.

author: GadgetBoy
author_rank: Regular Contributor
timestamp: March 20, 2019, 07:43:11 am
content: It takes 50-70 mA to cause a serious interruption in the heart.

author: Psi
author_rank: Super Contributor
timestamp: March 20, 2019, 12:11:20 pm
content: It's not an exact science as everyone's heart has a different tolerance to current.There have been lots of different current thresholds given by various sources about the point where it becomes 'deadly'.It's put somewhere from 30mA to 100mA for an average person.

author: Cnoob
author_rank: Regular Contributor
timestamp: March 20, 2019, 12:40:34 pm
content: How is an average person defined because a 4 year old is totally different to a 30 year old and a 30 year old is totally different to an 80 year old?

author: joeqsmith
author_rank: Super Contributor
timestamp: March 20, 2019, 12:46:24 pm
content: I thought the idea wasn't to show what was safe but at what point he couldn't release the probes. I would have ran a strap to my shoulder and left one hand free.Interesting comment about the mid range current causing the most problems. Does make some sense but I wonder if there is any data that supports it.I ran a similar test with a non-contact Fluke meter with my hand on a metal plate while holding the meter in the same hand. I did make some sort of body model for one of these tests to avoid pushing my luck. Basically this was done to demonstrate the meters internal network after watching a video from AEV.https://youtu.be/k8hhtTtWfVc?t=2632https://youtu.be/QsRwQIuTNmE?t=412

author: MT
author_rank: Super Contributor
timestamp: March 20, 2019, 01:35:14 pm
content: Electroboom soon to do a followup!

author: Psi
author_rank: Super Contributor
timestamp: March 20, 2019, 02:02:54 pm
content: Quote from: Cnoob on March 20, 2019, 12:40:34 pmAll the stats/tables are intended for people working in industry. So tend to ignore people to old/young to work.

author: richard.cs
author_rank: Super Contributor
timestamp: March 20, 2019, 06:31:24 pm
content: Electrical safety thresholds are mostly based on a set of research papers from the 1950s which basically involved applying electricity to US soldiers (not exactly general population in terms of age/fitness) and the occasional secretary. It's not exactly the kind of thing that could easily be repeated today.Based on that data, which is generally accepted, 10 mA hand to hand is considered safe indefinitely for a normal, healthy person.

author: janoc
author_rank: Super Contributor
timestamp: March 20, 2019, 10:36:42 pm
content: Quote from: richard.cs on March 20, 2019, 06:31:24 pmExcept how do you know that you don't have an undiagnosed heart problem? This is really a very dumb thing to do.

author: apis
author_rank: Super Contributor
timestamp: March 20, 2019, 11:22:29 pm
content: Found a series of interesting slides, not sure how accurate they are though:https://www.slideshare.net/YassirAliHassan/electrical-safety-41590043Summary:Unlucky that 50-60 Hz is the frequency we are most sensitive to.Mean let go current for men 16 mA (min 9.5). For women it's 10.5 mA (min 6 mA).Respiratory arrest has been observed at 18 - 22 mA.Main cause of death is ventricular fibrillation and for an average sized human varies from 75 to 400 mA.You would need to seriously zap someone to defibrillate!Clive got a contact resistance as low as 2615 ohm, that translates to let go voltage for women of min 16V@50Hz, mean 27V. For men min 25V, mean 42V. That's less than I would have expected to be honest. For children it would be even less I assume.Quote from: janoc on March 20, 2019, 10:36:42 pmYes.

author: golden_labels
author_rank: Super Contributor
timestamp: March 21, 2019, 01:38:21 am
content: I wonder how many people, who are criticizing Big Clive, worked on 30VAC circuits with bare hands…Science works and this is why Big Clive wasn’t even close to affecting his heart or chest muscles, much less the nervous system or other organs. I am really disappointed: the narrative I see in the responses is approximately the same as I would expect from people thinking “grapheme increases heating efficiency”, “power lines produce dangerous EM fields” and “mobile phones cause cancer because they microwave brain”. Fix your mental image of the situation. 230V is very dangerous, but not simply by being somewhere in the equation. Similarly there are currents which will cause fibrillation, but that doesn’t mean that any current will. And heart diseases are not magically lowering the threshold.My main problem with Big Clive’s experiment? If some kid will see his video, try to repeat that and harm themselves in the process, people will tear Big Clive apart. This, and not pushing 10mA through his body, is the main danger to which he exposed himself.The second issue is the way the experiment was conducted. It was sketchy as hell. As long as Big Clive was gripping both electrodes I wasn’t expecting anything bad. But careless manipulating the mess of live wires is a different thing. This is giving a bad example.Having a 10–30mA fuse on the input would also be nice in case something goes wrong (I know they are expensive, but $5–10 is not that extreme price too).

author: janoc
author_rank: Super Contributor
timestamp: March 21, 2019, 09:46:42 am
content: Quote from: golden_labels on March 21, 2019, 01:38:21 amYou are needlessly patronizing all the while making dangerous assumptions here. There are many other ways your heart could give out when hit by an electric current, not only by fibrilation. Had the current triggered arrhythmia (which is a common condition many have and don't even know about), he could easily have fainted - while still clutching the wire.The issue isn't the 10mA being safe or not but that nobody, most likely not even him, can be sure they are 100% healthy. A lot of heart problems are discovered only when you collapse and wake up in a hospital with a heart attack. Why to expose oneself to danger for no reason than a few minutes of Youtube fame? Feeling lucky, punk?

author: Psi
author_rank: Super Contributor
timestamp: March 21, 2019, 09:57:24 am
content: Quote from: golden_labels on March 21, 2019, 01:38:21 amyeah, but there are videos of far more dangerous things on youtube than what Clive did.

author: apis
author_rank: Super Contributor
timestamp: March 21, 2019, 02:16:54 pm
content: Quote from: Psi on March 21, 2019, 09:57:24 amYou mean the ones where Cody play with nitroglycerin (that was seriously stupid)? I prefer if Clive (and Cody) continue making videos.People who take a lot of risks often die in accidents it seems. Not from the really dangerous stuff but they get too comfortable around danger and so they become careless and eventually do some stupid mistake and something trivial kill them. Proper safety mentality is to always mitigate risk, not constantly challenge fate.

author: thm_w
author_rank: Super Contributor
timestamp: March 21, 2019, 08:22:37 pm
content: Quote from: joeqsmith on March 20, 2019, 12:46:24 pmStatistically he is right, there are a lot more electrocution deaths in US (110V) than UK (230V). Although that doesn't necessarily mean one voltage is safer than the other. I'm not sure if any study exists to actually back that up.https://www.quora.com/Which-one-has-more-fatality-110-volts-or-220

author: janoc
author_rank: Super Contributor
timestamp: March 21, 2019, 09:18:08 pm
content: Quote from: thm_w on March 21, 2019, 08:22:37 pmThat would be impossible to infer from something like that. From a purely physical point of view, 110V should be safer due to the lower voltage so it should be harder to get lethal amount of current through the body. One would thus expect lower amount of fatal injuries from it.However, that completely ignores the different standards between the countries (UK's beingnotoriousfor being obsessed with safety), different plug and outlet designs (safety again), general state of the wiring and levels of code compliance between the countries, etc.Possibly even education levels and attitude of people to electricity ("Ah, it's just 110V, will be alright!" vs "YOU DIE if you even look at that outlet wrong!").

author: drescherjm
author_rank: Contributor
timestamp: March 21, 2019, 09:46:04 pm
content: When he hit 9 mA I wanted him to give up. I did not want to watch anymore.

author: dnwheeler
author_rank: Regular Contributor
timestamp: March 21, 2019, 10:07:16 pm
content: Quote from: golden_labels on March 21, 2019, 01:38:21 amI don't think he ever manipulated live wires. The whole setup was switched by a foot switch which he only depressed during the actual tests.I still wouldn't do it, though.

author: Psi
author_rank: Super Contributor
timestamp: March 21, 2019, 10:09:26 pm
content: Quote from: apis on March 21, 2019, 02:16:54 pmI was mainly referring to other videos where people do something dangerous but secretly fake-it for the camera so it was actually totally safe for them.People watching don't know it was faked and may actually try it themselves for real.The risky part of videos like that is people thinking... "it was ok for him, it will be ok for me" when he actually never did it because actually doing so would be lethal.And a "Don't try this at home" warning on those videos does nothing to let people know the video was faked.Those kind of videos are way more dangerous that any video with a proper detailed safety warning at the start like what Clive didQuote from: dnwheeler on March 21, 2019, 10:07:16 pmThe foot switch only cut neutral. He picked up the resistor array a few times when it was live. However the two last resistors had a heatshrink cover, so the risk was just that he might accidentally touch the highest resistor tap and get the full 12mA.

author: thm_w
author_rank: Super Contributor
timestamp: March 21, 2019, 10:39:24 pm
content: Quote from: janoc on March 21, 2019, 09:18:08 pmI didn't say it was inferrable, just statistically it is the case that less issues occur with 230V.Big clives idea, if you watch the video this thread is discussing, is that the higher voltage will give you more of a "kick" and either push you away or completely stop your heart, which can then be recovered from. Whereas the 110V will be low enough to induce fibrillation, which is more deadly.Some references here imply this, but nothing concrete:https://hypertextbook.com/facts/2000/JackHsu.shtml

author: tszaboo
author_rank: Super Contributor
timestamp: March 21, 2019, 11:20:01 pm
content: Anyone is interested, he is rated for 0.408 Watts.People do dangerous stuff. Free climbing, parkouring, motorcycling, boxing, rafting, binge drinking, driving in Belgium. This is just the way we are.The climbing videos Dave does are more dangerous TBH. Although that setup could easily be knocked over and have a game over.

author: Deepak
author_rank: Regular Contributor
timestamp: March 22, 2019, 02:50:10 am
content: Quote from: thm_w on March 21, 2019, 10:39:24 pmEither voltage is capable of delivering a lethal shock. The voltage itself doesn't really affect the physiological response - that depends on how much current is flowing with a critical range between 100 and 200 milliamps as the fourth source in your link shows. Or a graphical representation here:https://www.asc.ohio-state.edu/physics/p616/safety/fatal_current.htmlThe problem is that it's not a straight I=V/R calculation since human tissue has a nonlinear resistance when exposed to electricity. On top of that environmental factors play a part as well. So while we can characterize the effects of the current, it's quite difficult to predictexactlyhow much current you'll sink.In addition to the fuse that was already mentioned, having an assistant with a 3.05 meter pole is always handy.

author: bloguetronica
author_rank: Frequent Contributor
timestamp: March 22, 2019, 03:14:01 am
content: Quote from: Mr.B on March 20, 2019, 12:53:36 amClive knows what he is doing. He is not borderline stupid, let alone stupid. Assuming otherwise is just plain arrogance.Kind regards, Samuel Lourenço

author: golden_labels
author_rank: Super Contributor
timestamp: March 22, 2019, 04:54:25 am
content: Quote from: janoc on March 21, 2019, 09:46:42 amFibrillationisarrhythmia. AFAIK the only type of arrhythmia induced by current. Correct me if I am wrong.Quote from: janoc on March 21, 2019, 09:46:42 amBut being unhealthy does not cause anyone to be more vulnerable to arbitrarily chosen things. There must be a specific mechanism of action that can cause harm. There is no magic. By this logic: since lying for 10 hours in strong sun can cause sunburns or even death, people with common cold (being ill) should avoid any contact with sunlight.Quote from: janoc on March 21, 2019, 09:46:42 amWhich heart disease can cause problems with arm-to-arm currents of 10mA applied for a short time?How surprising that people point to impossible scenarios like fibrillation or respiratory arrest, while the most probable one is not mentioned. He had flexors and extensors contracting at the same time. Be concerned with his tendons and muscles, not the heart.

author: Deepak
author_rank: Regular Contributor
timestamp: March 22, 2019, 02:15:32 pm
content: Quote from: golden_labels on March 22, 2019, 04:54:25 amArrhythmia is a class of conditions, and ventricular fibrillation is one of the types of arrhythmia. And there's a chain of logic where electricity affects muscle tissue, and the heart is made of muscle tissue, therefore there's a possibility that the threshold for symptom X is lower than in a healthy person. I don't think he was in danger of death with 10 ma, but I think you're being a little uncharitable to the argument from the other side.

author: Bud
author_rank: Super Contributor
timestamp: March 22, 2019, 02:51:30 pm
content: I am the one with a heart condition which is linked to the heart electrical activity. I do not recommend messng up with anything that may interfer with the heart's natural electric signals.

author: Zero999
author_rank: Super Contributor
timestamp: March 22, 2019, 09:20:38 pm
content: Quote from: tautech on March 20, 2019, 02:29:19 amDid the person with that handle die? I didn't know about it. Did you know him in real life?Quote from: golden_labels on March 21, 2019, 01:38:21 amThat's why, in the UK, anything above 25VAC needs to be insulated and that's only for dry areas, otherwise it's 12VAC and in high risk areas such as steam rooms, even that's not allowed: everything must be insulated! As Clive says, AC is more dangerous than DC, so the DC voltages where insulation is mandatory are higher, at 60VDC for dry areas and 30VDC for more damp locations.Another factor is potential contact area. When someone is working on a 30VAC circuit, it's unlikely they'll touch a large enough area of the conductor to pass over 10mA, so the risk is still relatively low.Quote from: Psi on March 21, 2019, 10:09:26 pmI thought that was the only really stupid thing about the experiment and he should have used an isolation transformer to avoid unintended paths to earth.

author: SenseofScale
author_rank: Contributor
timestamp: March 22, 2019, 09:47:44 pm
content: Maybe my ignorance has me paranoid but there are too many "what if?"s for me.

author: tautech
author_rank: Super Contributor
timestamp: March 22, 2019, 10:38:42 pm
content: Quote from: Zero999 on March 22, 2019, 09:20:38 pmYep, Garry was a pretty ill guy but what a character.We only got blessed with his banter here on the forum where we got to know him some and he helped bring some great humor to us all.One day he just stopped posting and I looked at the death notices from the area where he lived for a while for conformation of his demise but sadly couldn't find any.Like any flame that burns bright sadly they sometimes don't burn for too long.

author: Zero999
author_rank: Super Contributor
timestamp: March 22, 2019, 10:54:24 pm
content: Quote from: tautech on March 22, 2019, 10:38:42 pmHow do you know he didn't simply lose interest? People stop posting for a variety of reasons.

author: tautech
author_rank: Super Contributor
timestamp: March 22, 2019, 11:02:07 pm
content: Quote from: Zero999 on March 22, 2019, 10:54:24 pmWell if you look at his posts you might believe otherwise.

author: golden_labels
author_rank: Super Contributor
timestamp: March 23, 2019, 01:04:15 am
content: Quote from: SenseofScale on March 22, 2019, 09:47:44 pmThis is a very good heuristical approach. 230V can be very dangerous, so one should avoid risk while working with it. While unsure about the expected outcomes, just stop.But that doesn’t hold while criticizing the actions of other people. Big Clive is expected to know what he’s doing and he did his homework. He no longer needs to rely on heuristics. This works the same way as the fact that you do not need to make guesses while touching your LCD screen. You do that without hesitation, despite just few millimeters separate you from voltages in the kilovolts range¹. You touch your PC case, despite only few micrometers of the Y capacitor separate you from the 230V line.Quote from: Deepak on March 22, 2019, 02:15:32 pmThis is what I have written in the first 2 sentences of my message.Quote from: Deepak on March 22, 2019, 02:15:32 pmThe problem is that there is no chain of logic in that claim. There is a gap in the chain; it misses what I’ve asked for: the mechanism of action that would lower the threshold. I have also provided in my message an argumentum ad absurdum that exploits this very gap to “prove” nonsense. Have you read the whole message? If yes, why are the response contains a statement that has been already preemptively countered?The argument could hold if the current would be for example 10% from the point defined as the minimum current that is known to cause fibrillation. Not because the threshold is lowered below that point, but because of purely statistical reasons. Gaussian distribution has the tails, research is done on samples of limited size, it wasn’t done on humans², so some outliers may be missing. Therefore one could postulate that people with arrhythmia, who may be expected to be in the lower parts of the interval, may be affected by currents a bit lower than the defined current. But this is not the case: Big Clive was an order of magnitude lower than that. He was also below the average let-go current: the 10mA limit is set on the lower bound of the observed cases (see the attachment).Quote from: Bud on March 22, 2019, 02:51:30 pm… which bears no significance for the argument. I had cold this winter, but that doesn’t make me an expert on rhinoviruses³.Quote from: Bud on March 22, 2019, 02:51:30 pm… and the thing discussed here is that what Big Clive did was not affecting his heart in that way.____¹ Assuming CFL backlight.² The 1930s experiments were performed on multiple species of non-human animals, deriving a curve that approximated dependence of fibrillation current on animal size and heart size, and finally placing a human on that curve — which yielded 100mA as the minimum current that could cause fibrillation.³ To somewhat counter myself: there are some exceptions for people with rare diseases, as they may know more about their particular condition than most of the medical staff. But they are still not experts on the topic — it’s just that the other group knows even less.

author: Deepak
author_rank: Regular Contributor
timestamp: March 23, 2019, 02:02:26 am
content: Quote from: golden_labels on March 23, 2019, 01:04:15 amThat wasn't an ad absurdum, and it's easy to test by substituting different medical conditions. Say someone with lupus, or someone with skin cancer, or someone taking azathioprine. The logic of a condition making someone susceptible to environmental factors at lower thresholds is clearly sound because it's been documented countlessly in medical literature.People aren't always right on the facts, but you don't need to treat them like idiots for it. Not everything is barbarians at the gates.

author: golden_labels
author_rank: Super Contributor
timestamp: March 23, 2019, 05:07:26 am
content: Quote from: Deepak on March 23, 2019, 02:02:26 amWhat is it then? I took the original janoc’s argument and showed that it leads to nonsense. This is what reductio ad absurdum is, by definition.One can’t counter that ad absurdum by simply providing examples: they miss the target. Existential quantification (your examples) does not oppose another existential quantification (my ad absurdum).But even if I accept that argument… we are back to what I have said earlier. People you have mentioned are indeed more affected bysomefactors. But not byanyfactors. And those, which affect them, do that only if occurring in quantities covered by the mechanism of action of the given condition.Quote from: Deepak on March 23, 2019, 02:02:26 amI am not sure if you are referring to people treating Big Clive like an idiot, which I dislike and this is why I take part in this thread, or some action of mine. If the first: I don’t really see where it comes from, but I agree. If the second: what made you think I do treat someone as an idiot?

author: janoc
author_rank: Super Contributor
timestamp: March 23, 2019, 10:50:31 am
content: Quote from: golden_labels on March 23, 2019, 05:07:26 amIt leads to nonsense because you areby your own choicedeciding to ignore everything else but whatyouhave decided is the only possible outcome.There is no point to debate further something like that when you are refusing to accept that there could be other issues at play than that ventricular fibrillation (or that a fibrillation can be triggered by even lower currents due to e.g. a congenital defect) - issues that you are completely ignorant of. Which doesn't stop you from treating everyone else like an idiot.Enjoy

author: SenseofScale
author_rank: Contributor
timestamp: March 23, 2019, 12:58:22 pm
content: We can talk about statistical distributions based on the limited data we have but would you argue that the tail of the gaussian curve goes to zero before approaching 10 mA or that it so close that it's not worth worrying about? I see Big Clive's act as akin to playing Russian roulette with a gun that may or may not have a bullet in one of the chambers. Maybe there are even 100 billion chambers. In my opinion, it's not worth doing.Is this something you would do?I used to buzz people with insulation testers for my amusement. "Hey, let me check your resistance. There have been studies to show that a lower resistance across abc is an indicator of xyz." I didn't go across their heart, and these were meters of good quality that limited the output to less than 1 mA. At some point, I decided never to do that again because of the "what if?"s. What if they overreact and hurt themselves or me? What if the insulation tester fails and delivers a bigger jolt than expected and because of some oversight of mine, it does go across their heart and what if they also have a pacemaker?What if some of these resistors pass more current due to some unseen residue that got shifted while handing? What if the foot switch fails? What if clyde's composition happened to be so that more current traveled directly through his heart than the normal person? What if there happened to be a transient while he was doing this?Quote from: golden_labels on March 23, 2019, 01:04:15 am

author: Electro Detective
author_rank: Super Contributor
timestamp: March 25, 2019, 09:26:25 am
content: Clive should have better judgement than to perform stupid stunts like this,that's bound to attract copycat meatheads testing their "resistance to demise".Once you've had a good belt or two of 'can't let go' 240 volts (thanking God and Co. it wasn't 415/440/480v)and assorted low current HV electrostatic discharges that laugh at rubber and leather gloves and zap you anyway...you soon learn to stay 101% isolated from any voltages and currents,and ignore Darwin Award Candidates telling you to:'man up and take it''it can't harm you''I've done it lots of times, no worries'and other 'famous last words' BSHuman bodies were not designed for zaps,it's a short life, so don't risk shortening it further with dumbass tests like this, pushing your luck and assuming your health is good enough.If you really need 'know more' about it, brush up on Cardiology and the techno that supports it.Those pros know that gig a wee bit better than Big Clive, ElectroBoom,and other ~controlled mayhem~ cash counting Youtube showsters

author: joeqsmith
author_rank: Super Contributor
timestamp: March 25, 2019, 12:02:57 pm
content: Quote from: SenseofScale on March 23, 2019, 12:58:22 pmI was thinking that myself when watching. There were some simple things that could have been done to help reduce the risk but oh well, his choice. I ride a bike and people tell me about the risks. Still, I wouldn't want someone to take away my choice of riding one.There are a lot of high risk videos. Electroboom's MOT JL video rates up there, but this one still gets my vote:https://wixx.com/news/articles/2018/jun/22/files-video-released-in-fatal-shooting-recorded-for-youtube/

author: KL27x
author_rank: Super Contributor
timestamp: March 25, 2019, 07:57:33 pm
content: The "proper" way to do this, if there is one, would require a reliable active current limiter so you don't go from 3ma, to 3.5mA, but then accidentally jump from 8mA to 15mA.I don't care if people are dumb enough to do this, I just hope he doesn't end up suffering for other peoples' stupidity.QuoteAC might affect you at a lower voltage, but the effect will at least be somewhat more gradual as you approach your personal limit the way Clive is doing it. If he tried to do that with DC, I suspect it might be MORE dangerous. As in... nope. Nothing. Nothing. A tingle. Owie. Dead.

author: Zero999
author_rank: Super Contributor
timestamp: March 26, 2019, 12:13:59 pm
content: Quote from: KL27x on March 25, 2019, 07:57:33 pmWhat makes you think that?As far as I'm aware, the threshold for electrocution with DC is now more abrupt than AC, it's just a much higher current, therefore far less likely, given the same voltage. I've been shocked by a 30V transformer, yet at 70VDC I didn't feel anything. Of course I was just touching a wire, so the contact area and therefore current was much smaller, than in Clive's experiment.

author: KL27x
author_rank: Super Contributor
timestamp: March 28, 2019, 10:35:04 pm
content: I dunno for sure.If there were active current limiting, maybe it would be similar. But with the series resistor setup, I wonder if it would be more dangerous.With AC, some of the current might be due to some of your skin/clothing capacitance, maybe?With DC, once the voltage is high enough to exceed the dielectric value of your skin at the point where you are holding the electrodes, maybe it would be super more dangerous? Like up to 70VDC, it feels like any tingling is really just passing over your skin. It only tingles at the surface, at the contact point of the electrodes. You do not feel your muscles contracting and whatnot. But once that point is exceeded... Whereas with AC, the current is intermittently broke, (peak voltage of AC is higher, so some will get through at a lower voltage of course... , but maybe it is "breaking the arc" and starting over again on the next cycle... more gradually) so you feel it before the danger zone. Until the skin starts to cook and get more permanently damaged?The other thing is back when Edison was arguing/promoting DC for power transmission, there were arguments that DC is much more dangerous (let alone the efficiency sucking). I saw some stuff with electric chairs (AC) being unreliable on some people... And there have been some suggestions that DC would be more consistent/effective.The stuff we stick on our bodies to intentionally shock ourselves are AC. TENS units use AC. Stupid hand shocking gimmicks use ACI have always personally considered DC more dangerous (the number of volts not withstanding). I have never heard anyone say AC is more dangerous than DC prior to this thread.i think up until you exceed the dielectric value of the skin (or apply enough current through the electrodes for long enough to damage the skin in that area), that DC isn't really going through your skin, it's just 99+% travelling over it. But once you exceed that tipping point, you'd be in worse trouble?Lastly, we've all just watched Clive do this with 60Hz AC. So we know it's not insanely dangerous. I have never seen anyone do this with DC. Who wants a Darwin Award?*This might be grossly incorrect, but look at the waveform of AC. And imagine that you draw a line near the peak. And imagine this is the dielectric value of your skin. Only those peaks are getting through. Anything under that is just travelling over your skin, or not much at all. As the voltage crosses zero point, your skin acts like an insulator, again. As you increase the voltage, you are increasing the current that makes it through your skin only gradually, by slowly increasing that peak. But with DC, you slowly increase the voltage to push more and more current OVER your skin. Then where the dielectric of the skin is exceeded, you just changed from a 100K resistor to 100R. Your skin is maybe gonna act like a spark gap (or is it "arc gap?"). DC, this don't break as easily. Once that gap is crossed, it will continue until the voltage drops significantly lower than the breakdown voltage. Any dielectric value of the skin is completely bypassed. And underneath the skin, we're all just a bag of highly conductive Gatorade.When the dielectric breaks down, the voltage across you will drop, due to the series resistor now dropping more of that voltage. And hopefully, this arc will break. But in AC, you also have the voltage dropping to zero 60 times a second. So even if the DC arc does break, then your resistance goes back up (and voltage) and does it again.. the pulse duration and duty cycle can potentially be way way higher. IOW, in this experiment, where the current jumps from 7 to 10mA, with DC, there might be a jump from 3 to dead.

author: KL27x
author_rank: Super Contributor
timestamp: March 29, 2019, 12:13:09 am
content: There is another important disclaimer that Clive may have mentioned.He is doing this with 240VAC. If you were to try to recreate his setup with 110VAC, it would be more dangerous, IMO. Since humans are alternatively acting like highly resistive (when skin is insulating) and low resistance (when the skin is bypassed), the series resistor is going to be more effective when done at 240VAC. The human part of that circuit is much smaller at 240VAC. At 110VAC, you will go from tingle to danger/dead much more rapidly.

author: amyk
author_rank: Super Contributor
timestamp: March 29, 2019, 01:28:12 am
content: Quote from: KL27x on March 28, 2019, 10:35:04 pmI wouldn't consider that any evidence to the danger of AC vs DC; the reason they use AC is because you can get AC out of a step-up transformer immediately, whereas DC requires additional rectification.

author: Zero999
author_rank: Super Contributor
timestamp: March 29, 2019, 09:57:54 am
content: Quote from: KL27x on March 28, 2019, 10:35:04 pmThe capacitance due to the skin is tiny, much too low at mains frequencies to make any difference. What makes you think that DC travels over the skin, rather than through it? That makes no sense. The resistive part of the impedance is dominant. Capacitance won't make any difference, until hundreds of kHz and by then, there's no shock risk, only burns from Joule heating. If capacitance was a factor, then you'd get a shock by holding an insulated mains conductor, if the contact area was large enough.Countless studies on the threshold of pain/muscle contraction and death have been done, using different frequencies and currents and mains frequency AC has consistently been proven to be the most dangerous, much more so than DC. I don't know why the myth that DC is more dangerous, than AC still proliferates so widely today, when it's been know that the reverse is true for well over a hundred years.https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730001338.pdfhttp://www.wright.edu/~guy.vandegrift/wikifiles/Electric%20shock%20voltages%20Dalziel.pdfIf Clive repeated the experiment with DC, I'd expect he'd be able to take double the current without any ill effects. At 10mA, he'd receive one shock, when the current started, followed by a warm, tingling sensation, then another shock, when the current is interrupted.