USB charger is prime suspect in death of Australian woman

Re: More official advice completely divorced from reality

"Logically there is no real difference between using a mains-powered device while it is attached to the mains and using a portable device while attached to the mains. If anything the later is probably safer."

It is better you don't comment on things you don't understand.

that sort of logic does not come into it, rather an understanding of power electronics , waveform clipping and switch mode power supply will tell you EXACTLY WHY, your so called 'logic' breaks down, and it's all to do with size.

Here is a VERY simple experiment you can do.

Take one metal cased EARTHED computer, take one USB charger/hub ( just like the one you can buy off Ebay) do not connect the hub to the computer.

Using a multimeter set it to about 700Vac, now touch one lead to the 'metal' body of your computer and connect the other multi-tester lead to the 'shield' or the usb hub plug case.

Be prepared to be amazed…. then understand that it only takes a single capacitor or resistor to be out of spec for the available current to rise, or in the case of some really SHITTY usb chargers for the way you plug the charger into the wall adaptor to be reversed!!!!!

>> "Insulation on the pins of the plug" - are they suggesting that this was an issue in this case?

I believe said insulation is a requirement of the safety standards. Therefore lack of insulation would provide a quick and easy to spot warning sign to the customer that the device was non-compliant.

We can't expect everyone to buy their battery chargers from John Lewis.

Err... John Lewis is still a supermarket of sorts.

Frankly, any supermarket is a disreputable source as far as "own brand" electrical goods are concerned. They are sourced in a manner similar to horse lazagna and slavery prawns by the same sourcing department.

It does not cost much more to get a genuine charger or a proper CE marked 3rd party replacement nowdays from a proper online computer supplies shop. Misco/Global Direct and the More group taken together stock pretty much everything under the sun.

Interesting read in this context. Teardown of an Apple charger versus a cheapie replacement:

http://www.righto.com/2014/05/a-look-inside-ipad-chargers-pricey.html

I think it was more of a sound bite referencing standards; if the plug doesn't conform to Aussie standards, that's a good start to being suspicious about the quality of the device.

The same thing applies here to some degree, but sometimes those Chinese get confused and put insulation on the earth pin, which is a definite sign the thing isn't BS1363. (I've seen many other violations too).

"The offending one in my case was CE marked, and branded by the major electrical reseller were it was purchased."

Which is a major flaw in the official response. First, most consumers wouldn't know what the vast number of small print hieroglyphics on chargers mean. And second, even if they have some awareness those markings may either mean nothing useful (eg on untested kit), or have been applied fraudulently (eg on equipment the OEM knows is not compliant).

The CE marking shows this only too well. Supposedly meaning that a device conforms to EU standards, but widely understood to stand for "caveat emptor".

Re: Burn marks on her ears?

"2 electrodes, each connected closely to one side of the brain, what could possibly go wrong?"

Ve are goink to perforrm an electronik zerebrektomy!

Re: How?

Perhaps they were referring to the in-ear earphones of the type sold with iPods? They all have a fine mesh metal grille over the speaker.

Re: Possibly not a dangerous charger

I wonder if it is more likely a 220v 50Hz signal causing the coils in the earphones to superheat and melt/burn out. I've seen loudspeakers catch fire when subjected to these sort of low frequency overloads.

I guess, this could happen if the charger malfunctioned connected the positive mains signal direct to the USB ground, which would be then move the ground of the headphones from 0v dc to 220 ac. *shudders* so many horrible failure mechanisms when you start throwing mains voltage around headphones.

Almost makes me never want to wear headphones for work again.

..Something here doesn't add up.

http://www.smh.com.au/nsw/faulty-usb-phone-charger-blamed-for-sheryl-aldeguers-death-20140627-zsoc8.html

'..It is believed a dodgy $4.95 phone charger sent a high-voltage electrical pulse into her phone, which transferred to the earphones she had connected to a laptop.'

err, doesn't add up is a bit of an understatement..looks like journos getting a wee bit confused somewhere regarding the details of the case..that, or there's some mightily strange ear seeking electrical pulses doing the rounds in the southern hemisphere..

"OK the headphones were plugged into the laptop, and the laptop was plugged into... what?"

AFAICS it said she was wearing headphones and holding a laptop, but not that the headphones were plugged into the laptop: if they'd been plugged into her phone/MP3 player at the time, that would explain it all. The laptop would probably act as a convenient earth at her lap - current flowing between lap and ears would be a pretty bad arrangement medically.

Having said that, fake/dodgy chargers are not a USB only problem: I've seen some very nasty cheap laptop power supplies which could easily zap someone into an early grave if they're unlucky - and of course they're designed to deliver much more power than USB ones, which probably makes it even riskier for the user when things go wrong.

I've had some minor shocks when using two laptops at once - one Apple, one Dell, both plugged in to bona fide OEM chargers. Same result when touching a phone charging from the Apple USB ports, so I suspect it's just earthing current coming from the Dell - not nice, whatever the case.

https://shopping.hp.com/en_US/home-office/-/products/Laptops/HP-Pavilion/F2J07AA?HP-Chromebook-11-1101-PC-Made-with-Google-

HP Chromebook 11. Uses a microUSB charger.

Also known for its charger bursting into flames.

http://www.theregister.co.uk/2013/11/13/chromebook_11_pulled_from_sale/

http://www.theregister.co.uk/2013/12/17/hp_chromebook_11_charger_recall/

That said, the story doesn't add up.

Re: Sadly, I am not surprised this happened

The house fire that killed a family of five in Sheffield recently was blamed on a faulty USB charger. I would hope that UK TS is already paying more attention to this than to perfume and DVDs. Only a pity they didn't take more notice when the radio hams etc pointed out the sub-standard engineering of these things after noticing the interference they generate.

I try not to leave these little chargers on when out of the house or overnight, and if possible put them in places where a smoky expiry won't set anything else on fire.

An own brand USB hub from a reputable supplier lasted about a minute before a pffft signalled the demise of the "blob" power supply. A replacement lasted 10 minutes. A DLink hub has been running the keyboard and mouse for a couple of years since.

A recent purchase of some fence solar lights for the garden was interesting. After a few weeks one failed. Opening the unit showed that the small round-cell NiMh battery had split into two halves. In the process it had burned a neat round hole right through the plastic case - luckily not in contact with the wooden fence.

Mr Emery

if your power supply was on the duvet in bed then you deserve to be blown up. These things get warm - wrapped in a duvet or just resting on one can deny them of any cooling and the end result can be your bedroom getting more of a banging than it deserves.

However given human ignorance/stupidity perhaps the sensible safety standards for these things should include a thermal cut-out, however something that damages industry and not consumers is not going to achieve the brown envelop level of funding necessary to make it law.

Been the opposite case for me; I've had THREE genuine Apple, bought from a physical Apple Store, chargers blow up - I've now got 2 iDevices happily charging on no-name generics, which have been problem-free for >2 years.

Apple makes overpriced shite; I'm typing this on a 5th gen Touch, which is well out of AppleCare; due to the 'style over substance' way these things are manufactured, for the past year the screen has been parting company with the backplate, the resulting gap now being around 3mm or so - wife enough to slide a thumbnail into - and, in order to force it to charge - and to prevent the Home button falling out - I've a hair elastic round the base. If I didn't it'd be complaint that "this charger isn't certified…" - even though this iPod is using a genuine Apple charger - which hasn't exploded. Yet.

My old 4th gen on the other hand, has been subjected to some unspeakable abuses - including being dropped down the bog. Twice - and there's nary a scratch on it.

If there was another company which produced summat like an iPod, I'd never buy from Apple again. Even Apple appears to be considering dropping it…

RCD

Only if she was standing in a puddle in bare feet. RCD detects a mismatch in L & N current. If say the metal on an MP3 player connects to live (L) and the mesh on earphones connects to neutral (N) and you have insulating footware (most is unless hobnailed) then the RCD only sees a normal load while the poor human is toasted.

Re: Would a RCD have prevented this?

It depends. The switch-mode power supply in these chargers runs at around 350v DC - the result of directly rectifying the mains, before feeding it into an isolated DC-DC converter. If the fault caused this DC voltage to appear on the output then the RCD may fail to respond. This is because some types of RCD don't always work when the fault current has a large DC component. They use a current transformer to measure the current difference between Live and Neutral, and a large DC component would make the transformer core saturate and reduce its sensitivity. The better RCDs do it electronically, which is more expensive.

Re: Two problems:

I really don't know why people are so hung up on CE marks. Anyone can put one of these marks on their product. Counterfeiters aren't exactly going to decide to stick to the rules are they?

If you buy a piece of electronics from a market stall, it's likely to be a knock-off, simple as that. People only do it because they're so much cheaper than the real product. You're never going to get rid of this market, you're never going to get rid of counterfeit goods, and the only way you're going to convince people to buy the real thing is to make it more affordable. Fix the price of official chargers so that the manufacturers make minimal profits. More people will buy the real thing, offsetting the profit reduction with volume and the market for knock-offs will still be there, but be much less attractive.

Re: Two problems:

I argued against the CE mark system when it was proposed as a replacement for the Kite Mark.

Under the old system, items were sent away to a government regulated testing centre.

Under the CE system the MAKER just has to say it has been tested and is OK, there is no requirement for an external test lab to look at it until it blows up and kills someone.

So it is no good saying it is the Chinese makers faking a CE certificate - ALL CE certificate are worthless.