How unsafe can a china/ebay power adapter actually be?

[UPI]

Mean Well makes quality adapters if somebody is looking for one.

Thanks, I will take a look.

I received the DVE 12V 3A adapter mentioned above and it looks and weighs like a quality supply. I plan to put it up against my BK Precision Load when I get some time.

[TerraHertz]

Is this the first death by iPhone charger?
http://www.zerohedge.com/news/2013-07-15/ilectricchair-woman-electrocuted-death-her-charging-iphone
The iLectricChair: Woman Electrocuted To Death By Her Charging iPhone

If this happens too many times, the iCloud (tm) is going to need some PR reworking.

[free_electron]

my 5$ bet says she was using an aftermarket charger , which surged, shorted out across the HV/LV path and killed her...

[saturation]

Many appliance converters/chargers I've seen from China in the past 5 years are very dodgy, it wasn't so for many years before that.  The last one I bought was a simple DC-DC converter, and it blew up, nothing spectacular just smoke.   My mistake was not tearing it down before use, but its so compact and glued shut, I'd partially destroy it in the attempt.



I think the quest of Chinese electronic makers to lower price has reached a point where they are doing themselves a great disservice as now it will make it very difficult to trust even those makers with a streak of legitimacy.

Luckily, most cellphones have standardized on just mini-USB so there is no need to change PSU with each new phone.

I had to buy my recent crop of USB power supplies locally, but even at $10 each but  returnable, its better than $3 eBay from China that are fully unknown and could more than just fizzle on first use.

[nctnico]

Even the Chinese start to get affraid of Chinese products. Over here you can only buy one can of milk powder at a time because people are buying so much of it to send to China. Some people are selling Dutch milk powder on Ebay for big profits!

[Telequipment]

There is a program over here called rip off Britain, they featured these £3:00p iphone chargers off e-bay they were exploding everywhere, my daughter got one, it scared me so much her cheap one is in the draw and I bought her a proper iphone one at £26:00p, you can have the cheap china one for a teardown & destruction if you want it Dave.

[c4757p]

It boggles my mind that people actually buy these things so cheap. They're power adapters, it's not like they're consumables! I haven't had to buy one in months! If you can afford the item they power, surely you can easily afford one single power adapter for it??

I can understand it for heavy power consumers like laptops. Genuine laptop chargers are expensive. But cell phones and shit?

[Telequipment]

It boggles my mind that people actually buy these things so cheap. They're power adapters, it's not like they're consumables! I haven't had to buy one in months! If you can afford the item they power, surely you can easily afford one single power adapter for it??

I can understand it for heavy power consumers like laptops. Genuine laptop chargers are expensive. But cell phones and shit?

I quite agree , my daughters iphone came of e-bay refurbished, and this charger came with it, once I saw the program and look underneath it with e made in china , that was it  -out

[c4757p]

I will admit to having bought a cheap laptop charger, and I will admit to currently using it... (It's just for my old "backup" laptop while the good one's being fixed, though.) Not only is it suspiciously light, it's also suspiciously efficient. This laptop is running a long SPICE sim on all four cores, blasting its fan, and the adapter is hardly warm to the touch. The one that originally came with it got quite hot under such a load. I haven't bothered to stick a scope on it, but I doubt it's regulating very well.

Once my good laptop's back from the shop, I'll rip this charger open and see how close I've been to death...

[AndyC_772]

I think one of the problems is that it's virtually impossible to tell the difference between a cheap, nasty charger, a good quality charger, and a cheap nasty one that's sold at the same price as a good quality one. If I buy, say, a £25 charger, how do I know I'm not really buying a £3 charger and lining the pockets of a rip-off merchant as well?

[c4757p]

Not only is it suspiciously light, it's also suspiciously efficient.

Update: It's suspiciously light because it lacks proper EMI shielding. A crappy, homemade passive EMI loop probe was able to pick up nearly 10Vp-p unterminated, and -11dBm terminated into 50 ohms, just by waving around the exterior, and the waveform appeared to be only borderline stable... (Or you could call it unstable, there was a very low frequency oscillation at about 2 Hz.)

[Telequipment]

I think one of the problems is that it's virtually impossible to tell the difference between a cheap, nasty charger, a good quality charger, and a cheap nasty one that's sold at the same price as a good quality one. If I buy, say, a £25 charger, how do I know I'm not really buying a £3 charger and lining the pockets of a rip-off merchant as well?

I wondered the same as you so, I went to  apple direct, figuring at least if it went bang, I'd have someone official to go to. Personally I've become very suspicious of all of them, especially when its for my family.

[saturation]

There is an equivalent of the US CPSC in the UK, EU or other countries which holds the seller criminally liable for selling products that can harm the user.  So even if the device looks or actually are made by the same maker but one variation does not get as much QC, the importer is responsible for doing safety checking and due diligence.  In the USA, owners can sue them in civil court, Federal gov't in Federal criminal court, and each state in criminal court for each state.  That's what holds them incheck. 

The reason why tear downs are important in this forum, is you can use your electronic skills to examine if the product will live up to its specs or not.  When I bought my replacement charger I made sure it was screwed on rather than glued shut its not as slick as the small charger, but its safer.

I think one of the problems is that it's virtually impossible to tell the difference between a cheap, nasty charger, a good quality charger, and a cheap nasty one that's sold at the same price as a good quality one. If I buy, say, a £25 charger, how do I know I'm not really buying a £3 charger and lining the pockets of a rip-off merchant as well?

[Psi]

How unsafe can a china/ebay power adapter actually be?

Phase wire connected to case.

There you go, question answered and thread finished

From memory someone on this forum actually found that when inspecting some device they bought form china before powering it up.

[PedroDaGr8]

Can anyone recommend a good brand of brand new switch mode wall warts? I need several 12v 2A or greater with a 5.5 x 2.5mm barrel plug (preferably right angle).

I don't mind paying close to $20 for ones that come with an EEVBlog stamp of approval!

Is an FSP brand normally pretty well built?
http://www.ebay.com/itm/320756470445?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

If the FSP PSU is real, FSP makes some good stuff. They are one of the major ODMs in the PC power supply market and relatively well respected. They ODM for Antec, Thermaltake, Silverstone, Sparkle (so often that i used to think the S in FSP stood for sparkle), Zalman, etc. My favorite PC power supply maker is mainly Delta and eMacs. Another good one is the aforementioned Silverstone (some Silverstones are their own, others are from an ODM and yet others they ODM for other people).

[Phaedrus]

I actually work for Cooler Master (major PC Case/Cooler/PSU company). We used to use FSP a lot, and they were the better units on our low end. We've switched over to mainly Enhance, but I'd like to bring some FSP units back into the mix. They've got some good stuff.


Here's a crappy "400W" power supply I picked up at Fry's last year for $20. I knew it was going to be crap, but hoooo boy, I wasn't expecting this.






You gotta love that comprehensive line filtering. One NTC thermistor, a common mode choke and two Y caps. The fuse is a way over-spec'd 6.3A number. By the time the fuse blows the rest of the PSU will already be burning like an illegal fireworks van.





Crappy flyback topology with a single fet rated for 40A pulsed at 25C. It's got a crappy little transformer. Doubt it could load past 250W with that hardware.





The power supply label claims 29A on the +12V rail. The datasheet for that little schottky there on the left says 20A at 25C. Whoops.

The middle part is for the +5V rectification. I couldn't find a datasheet, but I suspect 30-40A at 25C. The one on the right is a 40A N-channel MOSFET for the +3.3V regulation.

+12V and +5V share the main inductor. This is called group regulation, if you aren't aware. It's great for saving costs (one inductor core, one rail wrapped in regular copper wire, another in enamel coated wire to prevent conduction). Problem is the +12V and +5V become magnetically coupled, which causes voltage regulation to go completely out the window. If one rail gets loaded too much higher than the other, voltage goes totally out of spec. The +12V and +5V/+3.3V loads have to stay within a certain (usually unknown) ratio or else you'll see terrible regulation. The +3.3V, by the way, is regulated down from the +5V output. This probably makes the +3.3V output the cleanest on the power supply, all things considered.





The +5VSB rail, on the other hand, rated for 2.5A, is using a ludicrously over-powered 30A schottky. I know,  They're only using half of it though, so it's just 15A. Still, why the hell didn't they swap that schottky in for the +12V rectification, and use some cheap 3A diode for the +5VSB? Words fail me.





Shit soldering. Love that big ground wire they had to solder in. I wonder if that might cause an internal ground loop, possibly mess with the control circuitry? High power multi-rail SMPS layout is black magic, so I'm not sure. Wait, did I say high power? Never mind, this thing doesn't qualify.





I saved the best for last. This power supply has NOT ONE filter cap on the +12V rail. Zero, zip, nada. Your motherbard, graphics card, hard drive motors, are getting pure, unfiltered, ripple-laden +12V straight from that cheap-ass schottky I showed you earlier. Ripple likely exceeds 200mV, easily. Might go as high as 300mV if you push it. I didn't have a scope or DC load at the time to test it, unfortunately.

Know what takes the cake though? The -12V rail -- yeah, that obsolete, near-deprecated rail that isn't used for anything but providing the negative rail for RS232 on ancient motherboards that don't generate their own voltage? That useless rail? That gets a filter cap. Oh yes, that was important enough to spend a few cents filtering. But the freaking +12V? Naaaaaaah. It'll be fiiiiiiine if we just feed pure switching noise into the motherboard. It won't hurt a thing.

Caps are cheap-ass ChengX parts, by the way.




This thing claimed on the box to be "Designed by Topower!" That would be real great, if this was 2007 when Topower actually made PC power supplies. Too bad they got out of the business in 2010 or so. This thing is designed and made by Leadman, aka "Powmax" (their old US retail ebay name) and imported by Topower to be sold by a retailer. An older revision (which was less shitty) was reviewed on JonnyGURU.com ages and ages ago. All of the changes were for the worse. So if Topower really did "design" it, as in take Leadman's crap and try to make it better... Well... Let's just say that all of the sudden I'm not very upset they're out of the PSU market.

[PedroDaGr8]

I actually work for Cooler Master (major PC Case/Cooler/PSU company). We used to use FSP a lot, and they were the better units on our low end. We've switched over to mainly Enhance, but I'd like to bring some FSP units back into the mix. They've got some good stuff.


Here's a crappy "400W" power supply I picked up at Fry's last year for $20. I knew it was going to be crap, but hoooo boy, I wasn't expecting this.






You gotta love that comprehensive line filtering. One NTC thermistor, a common mode choke and two Y caps. The fuse is a way over-spec'd 6.3A number. By the time the fuse blows the rest of the PSU will already be burning like an illegal fireworks van.





Crappy flyback topology with a single fet rated for 40A pulsed at 25C. It's got a crappy little transformer. Doubt it could load past 250W with that hardware.





The power supply label claims 29A on the +12V rail. The datasheet for that little schottky there on the left says 20A at 25C. Whoops.

The middle part is for the +5V rectification. I couldn't find a datasheet, but I suspect 30-40A at 25C. The one on the right is a 40A N-channel MOSFET for the +3.3V regulation.

+12V and +5V share the main inductor. This is called group regulation, if you aren't aware. It's great for saving costs (one inductor core, one rail wrapped in regular copper wire, another in enamel coated wire to prevent conduction). Problem is the +12V and +5V become magnetically coupled, which causes voltage regulation to go completely out the window. If one rail gets loaded too much higher than the other, voltage goes totally out of spec. The +12V and +5V/+3.3V loads have to stay within a certain (usually unknown) ratio or else you'll see terrible regulation. The +3.3V, by the way, is regulated down from the +5V output. This probably makes the +3.3V output the cleanest on the power supply, all things considered.





The +5VSB rail, on the other hand, rated for 2.5A, is using a ludicrously over-powered 30A schottky. I know,  They're only using half of it though, so it's just 15A. Still, why the hell didn't they swap that schottky in for the +12V rectification, and use some cheap 3A diode for the +5VSB? Words fail me.





Shit soldering. Love that big ground wire they had to solder in. I wonder if that might cause an internal ground loop, possibly mess with the control circuitry? High power multi-rail SMPS layout is black magic, so I'm not sure. Wait, did I say high power? Never mind, this thing doesn't qualify.





I saved the best for last. This power supply has NOT ONE filter cap on the +12V rail. Zero, zip, nada. Your motherbard, graphics card, hard drive motors, are getting pure, unfiltered, ripple-laden +12V straight from that cheap-ass schottky I showed you earlier. Ripple likely exceeds 200mV, easily. Might go as high as 300mV if you push it. I didn't have a scope or DC load at the time to test it, unfortunately.

Know what takes the cake though? The -12V rail -- yeah, that obsolete, near-deprecated rail that isn't used for anything but providing the negative rail for RS232 on ancient motherboards that don't generate their own voltage? That useless rail? That gets a filter cap. Oh yes, that was important enough to spend a few cents filtering. But the freaking +12V? Naaaaaaah. It'll be fiiiiiiine if we just feed pure switching noise into the motherboard. It won't hurt a thing.

Caps are cheap-ass ChengX parts, by the way.




This thing claimed on the box to be "Designed by Topower!" That would be real great, if this was 2007 when Topower actually made PC power supplies. Too bad they got out of the business in 2010 or so. This thing is designed and made by Leadman, aka "Powmax" (their old US retail ebay name) and imported by Topower to be sold by a retailer. An older revision (which was less shitty) was reviewed on JonnyGURU.com ages and ages ago. All of the changes were for the worse. So if Topower really did "design" it, as in take Leadman's crap and try to make it better... Well... Let's just say that all of the sudden I'm not very upset they're out of the PSU market.

Nice teardown, I wouldn't be surprised ifthe ripple was even higher than 300mV. NO filter caps at all is a first for me.

[Phaedrus]

The current record for highest ripple on an ATX power supply is 3000mV.

Yes. That's right. 3V of ripple on a +12V rail. And 1.6V ripple on the +5V.



http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=123


So 200mV, 300mV, even 400mV... That's bad, but it can't compete with the king.

[amyk]

The middle part is for the +5V rectification. I couldn't find a datasheet, but I suspect 30-40A at 25C. The one on the right is a 40A N-channel MOSFET for the +3.3V regulation.

SBL1640CT. 16A.

The +5VSB rail, on the other hand, rated for 2.5A, is using a ludicrously over-powered 30A schottky. I know,  They're only using half of it though, so it's just 15A. Still, why the hell didn't they swap that schottky in for the +12V rectification, and use some cheap 3A diode for the +5VSB? Words fail me.

My guess is they ran out of parts. Ditto for the missing 12V caps.

Leadman's spec for the LP8867 only rates it as 350W, and the numbers there are closer to the components you found.

This might be their OEM, and according to them the configuration you have is only 250W:
http://www.itxpower.net/english_pcpower_8867.htm

It's well-known that they'll put whatever label you want on your order, and there's probably multiple levels of reselling going on, which could explain how a 250W unit eventually gets sold to the consumer labeled as 700W(!). Leadman buys from an OEM and overrates by 100W, someone buys from Leadman and adds to the rating, etc. etc.

[tom66]

A quick rule of thumb I use with cheap ATX power supplies (non-APFC with 2x200V caps) is to take the capacitance figure and halve it. This gives you output power in watts very approximately. For example 470uF/2 = 235W maximum before ripple becomes excessive. Interestingly most of these supplies' output ripple fails due to the 100/120Hz component, because the input filter caps are undersized. This is purely a numerical coincidence but it works very well.

In JohnnyGuru's example, notice above the 111W test the ripple exceeds the rated limit (120mVp-p) and the capacitors are 220uF, which estimates 110W limit. At 180W it's through the roof.  You can clearly see a 100/120Hz component to the ripple.

[Phaedrus]

Current wisdom is that Leadman is the original equipment manufacturer for the 8860/8867 power supplies. However, this is based on research done by members of JonnyGURU.com years ago, so the information could very well be wrong or outdated.

Running out of parts was my supposition for the odd component choices as well. Still, you don't keep selling fans after you run out of motors to put in them. It's inexcusable. But I guess that in a race to the bottom...

[Phaedrus]

If the FSP PSU is real, FSP makes some good stuff. They are one of the major ODMs in the PC power supply market and relatively well respected. They ODM for Antec, Thermaltake, Silverstone, Sparkle (so often that i used to think the S in FSP stood for sparkle), Zalman, etc. My favorite PC power supply maker is mainly Delta and eMacs. Another good one is the aforementioned Silverstone (some Silverstones are their own, others are from an ODM and yet others they ODM for other people).

Silverstone don't ODM, they're a US marketing company. They use FSP and Enhance.

There are only three major brands selling retail in the US that have their own factories:

FSP (major global ODM, does minor US retail)
SeaSonic (boutique, high-end PSU ODM, sells retail as a type of B2B marketing)
Enermax (Has their own factory for their high-end stuff, has engineers from their Impervio acquisition in 2007. Low end is Channel Well made)


There are a few other ODMs that sell under their own name in APAC, including SuperFlower and HighPower (neé Sirfa, neé Sirtec).

[saturation]

Thanks for the SMPS teardown.  This is an example of someone importing ODM gear and doing their due diligence to sell these items in the USA.  Kudos to you!

On those PSU, are they UL, ETL etc., or equivalent tested for safety?

Silverstone don't ODM, they're a US marketing company. They use FSP and Enhance.

There are only three major brands selling retail in the US that have their own factories:

FSP (major global ODM, does minor US retail)
SeaSonic (boutique, high-end PSU ODM, sells retail as a type of B2B marketing)
Enermax (Has their own factory for their high-end stuff, has engineers from their Impervio acquisition in 2007. Low end is Channel Well made)


There are a few other ODMs that sell under their own name in APAC, including SuperFlower and HighPower (neé Sirfa, neé Sirtec).

[Phaedrus]

The cheap ones? No. Those usually just have a "China Export" mark (lol btw). Fake RoHS are everywhere. Occasionally you'll see a fake FCC compliance mark. Occasionally fake TUV or C-Tick. You used to see fake UL marks a lot, but not recently; I guess UL got off their butts and sued a few of those guys. I once saw a fake TUV badge that said "Taiwan Universal Verification" under it. 

Fake 80PLUS logos are common, but only on the packaging; you rarely find a fake mark on the PSU itself. And 80PLUS is easy to game in general, there are several units on the market where a completely different unit was sent in for certification, than are actually sold to consumers. Raidmax AE series is an example (the PSU you get one you buy one is actually a borderline 80PLUS White/Bronze unit. Made by Andyson). However, everyone in the business sends in golden samples, tested to perform well electrically, then modified to have shorter cables (less voltage drop). This isn't so much to get a higher certification though, as it is to protect your investment. You don't want to fork over the $5000 for the certification, then find that you missed your intended certification level by 0.2% and have to pay another five grand.


Quality PSUs will have all relevant certifications for their regions. (real) CE, FCC, UL, TUV, C-tick, RoHS, 80PLUS, etc.

[redtails]

@Phaedrus

I'm willing to bet the vast majority of quality markings (CE, FCC, RoHS, TUV, C-Tick, Safety Mark, etc) are fake. I won't say it's the case if you're buying a known brand of electronics, professional gear or medical gear, but that's not really the topic here. I can imagine many of the "Things and Trinkets stores" stock up on the absolute worst that China has to offer. As with many things, expensive stuff are always cheaper.

The attached images are shocking. It's a combined 12V+5V for an external harddrive enclosure that I got from eBay. I always test the PSUs before I use them on my gear, so when I turned this puppy on for the first time; it simply gave a loud bang and the sound of glass shattering. A faint but familiar burnt plastic air filled the room, and I knew what was going on. The glass fuse popped during first use. I later got another one from the same seller (I complained I wanted my money back, I'm greedy  ). The second one didn't explode, but even unloaded it got too hot to touch, so I ended up never using it