Another tragedy: cellphone chargers and bathtubs don't mix - Page 1
Forum section: electronics / general

author: cdev
author_rank: Super Contributor
timestamp: January 03, 2018, 12:57:55 am
content: http://www.dailymail.co.uk/news/article-5229185/Woman-electrocuted-charging-phone-near-bathtub.htmlAlso:https://www.thelocal.fr/20180102/pregnant-frenchwoman-electrocuted-in-bath-when-charging-phoneThere has to be some better way to charge phones than SMPSs.. Also we need people to be more electrically literate.

author: wraper
author_rank: Unknown
timestamp: January 03, 2018, 01:02:26 am
content: Quote from: cdev on January 03, 2018, 12:57:55 amThere is no safety issue with chargers unless save pennies by buying cheap counterfeits.

author: Aodhan145
author_rank: Frequent Contributor
timestamp: January 03, 2018, 01:02:37 am
content: I don't think SMPS are to blame the last one I know of the man had an extension cord on his chest in the bath.

author: orion242
author_rank: Unknown
timestamp: January 03, 2018, 01:20:10 am
content: Quote from: cdev on January 03, 2018, 12:57:55 amSeems like there are about a million ways better than charging it while in the tub. Hard to stupid proof.

author: amyk
author_rank: Super Contributor
timestamp: January 03, 2018, 01:28:00 am
content: Another Darwin Award candidate, literally. Can't you just...notuse your phone for however long it takes to have a bath?

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 03, 2018, 01:35:22 am
content: Why don't people just use an external battery pack instead of the mains? You can even get ones that are waterproof!

author: james_s
author_rank: Super Contributor
timestamp: January 03, 2018, 02:12:21 am
content: I strongly suspect it was either a defective counterfeit charger or the shock came from the mains plug rather than the output of the charger. Either way I consider this a demonstration of the theory of evolution. It does not take a genius to determine that using electrical devices while in the bath is a bad idea. It's probably a good idea to put down the phone now and then for long enough to take a bath. Modern smartphones are a great convenience but many people are completely addicted to the damn things.

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 03, 2018, 05:01:31 am
content: Quote from: amyk on January 03, 2018, 01:28:00 amThat's funny, because here in the US we have a commercial for a contract where the first scene is a woman watching Game of Thrones on her phone...in her bathtub. Nice role model. Granted, it wasn't plugged in, but the modern generation have no concept of safety and think it's ok to charge it.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 03, 2018, 05:07:37 am
content: Quote from: amyk on January 03, 2018, 01:28:00 amWhat else are water proof electronics for?

author: Electro Detective
author_rank: Super Contributor
timestamp: January 03, 2018, 10:37:23 am
content: Was the deceased talking, texting, Ebay surfing, snapping a nude selfie,or tappingLIKEfor some trivial BS posted on FarceBook ?Just curious...

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: January 03, 2018, 11:14:51 am
content: One of the concerns over SMPS is that a short across the transformer could put something over 500v on the phone - The mains ACplusthe peak DC on the transistor. That's potentialy a lot more dangerous than an insulation failure on an ironcore transformer, which puts mains AC on the phone only.Likely the charger had been faulty for a long time but it went unnoticed because people generally don't touch the metal parts whilst being themselves earthed.It takes two things to cause an electrocution: A live connection and anearth. The reason bathrooms are a hazard area is not so much because of the live, which is the same as present elsewhere in the house, but the multiplicity of earths you can attach yourself to.

author: Zero999
author_rank: Super Contributor
timestamp: January 03, 2018, 12:39:56 pm
content: Quote from: blueskull on January 03, 2018, 11:23:08 amThat's true.I would have also thought that any high frequency, high voltage AC component on the output of the charge would be short circuited by the numerous decoupling capacitors, causing a high current to flow and destroy the switching transistor.It wouldn't be the HF AC which would kill, due to an insulation failure, but the mains voltage, which will be present, even if the switching transistor is toast.

author: GreyWoolfe
author_rank: Unknown
timestamp: January 03, 2018, 12:52:11 pm
content: My wife also plays on her phone while soaking in the tub. However, she knows better to have it plugged in. She only did that once and I gave her a ration of sh*t about it.

author: Lord of nothing
author_rank: Super Contributor
timestamp: January 03, 2018, 01:05:57 pm
content: Quote from: amyk on January 03, 2018, 01:28:00 amYou never received an nude pic from the Bathroom who the Gender you pre fare.

author: jolshefsky
author_rank: Regular Contributor
timestamp: January 03, 2018, 01:22:26 pm
content: Quote from: blueskull on January 03, 2018, 11:23:08 amJust to clarify, while you won't feel it, current still kills.

author: orion242
author_rank: Unknown
timestamp: January 03, 2018, 01:23:13 pm
content: Quote from: IanMacdonald on January 03, 2018, 11:14:51 amWhich is why at least here in the US, GFCI receptacles are required in the bathrooms and have been for a some time now. Another layer trying to stupid proof.

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: January 03, 2018, 01:29:46 pm
content: The transformer is always on the 'hot' (collector/drain) side so it makes no odds if the switching action stops.A bridge rectifier provides about 300VDC (UK) between the 'floating' negative rail of the SMPS and the collector. The negative rail in turn swings between live and neutral at 50Hz. Hence something approaching the peak-to-peak mains voltage between transformer primary and earth at certain times in the AC cycle.Statistics show that electrocutions are actually quite rare, but the ones that do occur almost always involve wet hands and/or feet. Especially if the water is not pure, because salts greatly increase its conductivity. Garden power tools are a particular risk area, and these should always be used with an RCD/GFI.In the UK, no sockets are allowed in bathrooms other than shaver sockets, which must be isolated. Even these are becoming rare are most shavers are rechargeable these days so no need for them. Unfortunately that may actually lead to a greater hazard where an idiot uses an extension lead to get around the restriction, but hey, Darwinian evolution needs a modus operandi.

author: cdev
author_rank: Super Contributor
timestamp: January 03, 2018, 01:49:47 pm
content: My electric toothbrush uses a induction charging method. It seems the coil and oscillator are likely potted and there are no exposed wires in the AC cord after it leaves the plug at all. (although I amnotwilling to test this hypothesis out by immersing it in a grounded bathtub filled with water and measuring the leakage, safety interlocks can always break.)Its a "sonicare" brand, have had them forever, its my third or fourth one.The toothbrushes are plugged into a GFCI outlet.Bathroom and kitchen counter outlets and basement laundry zone are each protected by a GFCI - one each. Would a GFCI have prevented the young lady's electrocution (or a different charging method that used induction?)Probably.Maybe we should switch to only using low voltage DC in bathrooms? Or exclusively using DC fixtures for new work. Maybe 12v or 6v DC, and they could also provide USB sockets for power.People could then plug in their electronics without fear. (also instead of chargers they would just need a USB cord)I actually think we could easily switch to DC in our homes for most lighting and electronics uses.I would be fine with that, as long as it was a gradual transition. I think many of us would be.

author: bd139
author_rank: Super Contributor
timestamp: January 03, 2018, 05:01:08 pm
content: I feel sorry for the husband and baby but fuck her for doing something bloody stupid.In the UK we have possibly the best solution. No outlets in the bathroom, proper insulation everywhere. All the "shaver sockets" have an isolation transformer in them and a different socket.All bathroom deaths here in the UK are either some idiot running an extension lead into the bathroom or earth faults from bad electrical work.Bad electricians are rife though in the UK. I know one and I would rather hire a fucking monkey.

author: orion242
author_rank: Unknown
timestamp: January 03, 2018, 06:09:43 pm
content: WTF do the ladies do with their 1500w hair dryers, curling irons and whatever else?

author: bd139
author_rank: Super Contributor
timestamp: January 03, 2018, 06:12:02 pm
content: That happens in the bedroom.

author: chris_leyson
author_rank: Super Contributor
timestamp: January 03, 2018, 06:30:49 pm
content: QuoteAssuming the primary reservoir cap is charged via a bridge rectifier then during one half of the cycle the positive terminal will see plus mains peak voltage and the negative terminal will be at neutral and on the other half of the cycle the positive terminal will be at neutral voltage and the negative terminal will see minus mains peak voltage. The positive terminal is a positive going rectified sine and the negative terminal is a negative going rectified sine with respect to neutral (earth). Peak voltage on any terminal would be 340V assuming 240V rms mains.A short in the transformer to the positive end of the primary winding would give +340V recctified sine on the secondary and a short from the auxilliary winding would give -340V rectified sine on the secondary side as the aux winding is connected to the primary cap negative terminal. A failed Y cap, for EMC purposes, across primary and secondary would give + or - 340V depending on how it was wired in. Finally a short to the switching node would give 400V to 500V pk-pk at 100kHz or so but not for long as the excessive load would stop the switcher. In the case of a self oscillating or blocking switcher a short to the feedback winding would have the same effect as a short to the aux winding in proper controlled switcher.

author: Someone
author_rank: Super Contributor
timestamp: January 03, 2018, 09:40:12 pm
content: Quote from: blueskull on January 03, 2018, 11:23:08 amThere may be a higher threshold for sensation but there is still risk of death at a certain point:http://web.eecs.utk.edu/~dcostine/ECE482/Spring2015/components/equipment/High_Voltage_Safety_Manual.pdfI'm lacking the standards to hand that have the relevant graphs in them but there are well defined limits for voltage exposure to humans across the range of frequencies.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 03, 2018, 09:48:57 pm
content: Quote from: bd139 on January 03, 2018, 05:01:08 pmTo be fair, bathroom deaths are very rare in other countries without isolation transformers too, at least in this part of the world.

author: Lord of nothing
author_rank: Super Contributor
timestamp: January 03, 2018, 09:58:00 pm
content: How about grounding and have an good cirque breaker (or how does it spell right)?

author: Red Squirrel
author_rank: Super Contributor
timestamp: January 03, 2018, 10:16:01 pm
content: Is it safe to assume these incidents are because if isolation failure? ex: 120v making it through to the lead due to a fault in the transformer? I just don't see how 5v from a small wall wart (heck even a high amp source) would be enough to kill someone, even with water involved.That said I personally would not want to bring my phone in the bath tub anyway in case I drop or get it wet... and I would have no reason to bring the charger with me even if I did bring it. People are odd.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 03, 2018, 10:21:11 pm
content: Quote from: Red Squirrel on January 03, 2018, 10:16:01 pmAs I've stated before, many phones and devices are water resistant or water proof nowadays. Taking those in the bathrooms isn't a stretch.

author: Electro Detective
author_rank: Super Contributor
timestamp: January 03, 2018, 10:47:21 pm
content: Quote from: IanMacdonald on January 03, 2018, 01:29:46 pmAgreedbut still a russian roulette affair whether it trips when you REALLY need it to, as you don't know which combo of the 3 wires will get cut, break, de-strand, tarnish, bad/dirty contacts,or the 'bargain' cheapie tool (rebadged TooHungLo 'Gardren Freind') develops a gross fault etc etcAn RCD/GFCI with a separate fast acting dual pole MCB next to it (rated 6 to 10 amps max, or just past the tool/s startup current and full load) is what you need in the garden,to keep it and you looking trim, fit and alive.A power strip with a slower thermal overload breaker is another handy addition too, it's cheap and complements the GFCI/RCD and MCB combo,and pretty much covers the user against 'most' garden disastersexcluding- Advanced Dumbassery -If you have to work in rain and waterand certified insaneadd a grounded isolation transformer before the items above, and test the RCD/GFCI with an external tester before each backyard session.Do not just rely or trust the RCD/GFCI 'Test' button, or it may be the last time you do any gardeningand grievingor relievedpartnerwill have to shop around and hook up with a new or used partner, to tend to the ongoing hedgework and bare rooting duties

author: bd139
author_rank: Super Contributor
timestamp: January 04, 2018, 12:05:50 am
content: Just with respect to GFCI or RCD devices, I always work with these on the basis that they're there to stop the person who sees you being electrocuted from being electrocuted, not you.Procedure and thought save a lot more lives. The above are just damage control.

author: james_s
author_rank: Super Contributor
timestamp: January 04, 2018, 12:14:37 am
content: Quote from: Mr. Scram on January 03, 2018, 05:07:37 amRain? Puddles? Swimming pools? Boating? Falling out of your pocket into the toilet? I know several people who have ruined phones that way.I can see a lot of applications for waterproof electronics, I've never had any inclination to play with electronic gadgets while bathing.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 04, 2018, 12:24:51 am
content: Quote from: james_s on January 04, 2018, 12:14:37 amHaving waterproof gear around or in the swimming pool makes things a bit more relaxed. Read a bit, drop your phone, no problem.

author: bd139
author_rank: Super Contributor
timestamp: January 04, 2018, 12:26:23 am
content: I lost a Windows phone to rain. Waterproof is pretty important.Also I dropped my 6s in a sink (alcohol may have been involved). Not officially specified as waterproof but apparently it is!

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2018, 01:16:31 am
content: Quote from: bd139 on January 04, 2018, 12:26:23 amYep, teardowns of the 6S showed that it's got quite a bit of seals, despite not being sold as water resistant. Some people speculate that it was an unadvertised "trial" of the water resistance to see whether it would hold up well enough, and maybe whether it reduced warranty claims. I suppose it worked out, since the iPhone 7 is sold as water resistant.

author: james_s
author_rank: Super Contributor
timestamp: January 04, 2018, 01:24:11 am
content: People are going to interpret "water resistant" in different ways. I think it's reasonable to include seals even if you do not intend to make the device truly water resistant. Rain is inevitable and no smartphone should be damaged by getting a few raindrops on it. Seals also keep dust, lint and other debris out.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 04, 2018, 01:29:09 am
content: Quote from: james_s on January 04, 2018, 01:24:11 amSmart phones are objects that get kicked around by people in a variety of settings. Though there are limits to what can reasonably expected, you shouldn't lose warranty over pulling it out of your pants while it rained a bit or it even just getting damp when in your pocket. Those are just everyday situations and a phone should be able to handle that without problems. It's almost like losing the warranty on your car for braking hard. It's should be able to handle that.

author: james_s
author_rank: Super Contributor
timestamp: January 04, 2018, 01:31:04 am
content: Yes that was my point. That's all perfectly reasonable but if you call something "water resistant" people are going to assume they can take it into the shower with them or go for a swim with it in the pocket of their shorts.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 04, 2018, 01:41:57 am
content: Quote from: james_s on January 04, 2018, 01:31:04 amPeople should have learnt by now that water resistant and water proof aren't interchangeable. If they haven't, they are going to learn that lessons at the cost of one (1) smartphone. Consider the cost of education nowadays, that seems very reasonable

author: Electro Detective
author_rank: Super Contributor
timestamp: January 04, 2018, 03:33:54 am
content: Why risk your phone to the elementsand alcohol fueled dumbasserywhen there is access to plastic food wrap and clear resealable lunch bags,at a nano-fraction cost of a replacement phone ?And it avoids the ball breaking affair of losing messages, links, recipes, photos, telemarketing prospects, Nibiru offline maps,and having to re-enter data for Contacts, reminders, calenders, FarceBook,and all the other BS that portable device slaves fill their glued life support palm clamp withEnjoy your bath, shower or swim without the freakin phone,just think of the fun you'll have afterwards, catching up with what you missed during those few minutes that felt like forever...

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 04, 2018, 04:07:21 am
content: A heart attack at 21? Highly unlikely, she'd have to have been pretty unhealthy then (some aweful condition), and probably shouldn't have been having a kid (if heart attacks were a risk).If she reached over and grabbed the phone, or a freyed extension cord (most bathroom plugs I know of are near the sink, so she was probably using a cord), then she would have been killed and her limp corpse would have dropped the phone/cord back on the floor.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 04, 2018, 04:17:46 am
content: Quote from: Cyberdragon on January 04, 2018, 04:07:21 amA heart attack can strike anyone at any time. An unhealthy lifestyle, other bad choices or simply age can increase the chance of getting one, but young and very healthy people have been known to simply drop dead. It's not incredibly rare either.

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2018, 04:35:07 am
content: Quote from: Cyberdragon on January 04, 2018, 04:07:21 amIt happened to a friend of mine, who was in perfect health, slim, not a heavy drinker, no smoking or drugs. Luckily he survived it with no lasting damage.

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 04, 2018, 05:07:44 am
content: It would be early heart disease then. Still one of a few severe disorders, just in your cases, undiagnosed.https://www.acsh.org/news/2016/02/18/heart-attacks-can-strike-young-adults-so-know-the-signshttps://www.mayoclinic.org/diseases-conditions/sudden-cardiac-arrest/in-depth/sudden-death/art-20047571