How unsafe can a china/ebay power adapter actually be? - Page 1
Forum section: electronics / general

author: Razor512
author_rank: Regular Contributor
timestamp: December 16, 2012, 12:10:48 am
content: just discovered the EEVblog youtube channel and am completely hooked on watching all of the videos.Was looking at the video on the chinese iphone chargers, and decided to take apart a 9V adapter that I got from ebay for $1.50 including shipping from china and the design seemed even simpler. (got it a few years ago to replace the broken adapter for a old land line phone)took a picture of the insideChinese Power AdapterbyRazor512, on Flickr

author: JoannaK
author_rank: Frequent Contributor
timestamp: December 16, 2012, 12:14:29 am
content: Well, if that Transformer (hefty metal Chunk) is well made, then it's most likely ok. It's really old design, though. Nowdays allmost all systems tend to be Switch mode power supplies cause those can be made smaller (and cheaper)

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 16, 2012, 12:26:59 am
content: Quote from: JoannaK on December 16, 2012, 12:14:29 am..and with more scope for being dangerous.. fire, electrocution, damage to connected equipment, interference....

author: c4757p
author_rank: Super Contributor
timestamp: December 16, 2012, 12:39:39 am
content: Yeah, it's hard to beat mains transformer -> rectifier -> filter capacitor for fewer points of failure. If that transformer's not a piece of shit I have no problem with this.

author: tom66
author_rank: Super Contributor
timestamp: December 16, 2012, 12:53:09 am
content: That cheap cap might go bad after a few years, but screw it, it's $1.50.

author: mariush
author_rank: Super Contributor
timestamp: December 16, 2012, 01:02:01 am
content: That's actually a rather good looking chinese adapter.Here's what my mom bought a while ago from a "everything for a dollar" type of shop in my country... it can be scary sometimes:Spot the typo on the label, the quality of the pcb and the pads, how the solder is dumped on it and how the transformer is connected. Oh, and to add insult to everything, I think that capacitor was rated for 10v (not that it would have mattered)PS. I actually ordered a cheap 1.69$ usb charger as order filler when buying some stuff from DinoDirect and it arrived a few days ago :http://www.dinodirect.com/eu-plug-usb-ac-dc-power.htmlInsides look like a typical two transistor switching power supply but it's only half wave rectified (single diode on live) and puny caps (2.2uF 400v and a 20uF 10v on the output)... oh... and what i think it's a pcb fuse (trace goes very thin for about half a cm on board)... i'm trying to finish these days my constant current load and I think I'll make a video with tests of this adapter to see what it's capable of.

author: Psi
author_rank: Super Contributor
timestamp: December 16, 2012, 04:03:07 am
content: Quote from: Razor512 on December 16, 2012, 12:10:48 amPhase can be connected to the output due to being assembled by 8year olds with no electrical knowledge.That's how unsafe they can be.

author: SeanB
author_rank: Super Contributor
timestamp: December 16, 2012, 05:14:38 am
content: Razor, that one has a thermal fuse, a thing often omitted on the cheapies, along with any fuse. Double isolation layers, separate bobbin for the secondary, all makes it safe enough to pass the actual type certification testing.

author: FenderBender
author_rank: Super Contributor
timestamp: December 16, 2012, 05:19:41 am
content: I don't know...For$1.50 shipped, that seems like a reasonable adapter. I don' think it's the best ever but hey, full wave rectifier. Transformer looks okay.

author: Razor512
author_rank: Regular Contributor
timestamp: December 16, 2012, 05:56:05 am
content: glad to know it is not too horrible, I have not purchased an adapter from ebay in a long time (just don't feel right using a $1-2 adapter on a smartphone or other expensive device, especially with the crappy power where I live, power is suppose to be 120V but when testing with a multimeter, the power will sometimes be 110 and other times it will go up to 135V and since it is a really old house, most of the outlets are not grounded

author: T4P
author_rank: Super Contributor
timestamp: December 16, 2012, 07:23:21 am
content: But it's unregulatedI bought several brand new power packs for very cheap from a shop in china and they are a genuine surprise ... full-wave rectifiers isolation slots and MOVs(Surprise, surprise)!the good stuff never seems to go out of china only the bad ones

author: SeanB
author_rank: Super Contributor
timestamp: December 16, 2012, 07:31:19 am
content: One I got in a pack did not even survive more than 2 seconds. plugged it into a socket, turned it on and bang, dead and smoke puff. Cheap n Nasty junk. Took it apart and clearances were non existent, single diode rectifier and poor quality noname caps inside, along with no regulation or any isolation other than the wire enamel and the single turn of tape.

author: JoannaK
author_rank: Frequent Contributor
timestamp: December 16, 2012, 08:37:18 am
content: Quote from: SeanB on December 16, 2012, 07:31:19 amI had one cheapo-bran energy-save fluorecent lamp that died at the instant I turned light switch. Well, at least it was easy to replace and it didn't burn down the entire aprtment.

author: JoannaK
author_rank: Frequent Contributor
timestamp: December 16, 2012, 08:49:39 am
content: Quote from: mikeselectricstuff on December 16, 2012, 12:26:59 amYep. In a wordDeadly

author: Fraser
author_rank: Super Contributor
timestamp: December 16, 2012, 09:42:45 am
content: Due to the horrors that I have seen on the EEVBlog in the past, I no longer buy cheap power supples from China. The risks to safety and the equipment are just too high. Any saving could quickly be lost. The really scary fact is that some of these really nasty SMPSU's are appearing in UK retail shops on the highstreet. They look the business, complete with posh packaging but they are total rubbish inside. I bought a 'quality' Universal Ni-Mh charger block from a UK source for around GBP25 so it wasn't a real cheapie. When I opened it I was horrified by the poor soldering and total cr*p pcb layout. It was a linear design but the transformer became very hot in use, to the pont that it could not be touched. I binned the unit as a fire risk and poor design. In retrospect I should have reported it to trading standards to get it withdrawn from sale. I have attached a picture of the rubbish Ni-Mh charger.I bought several Ansmann XBase Deluxe Universal Chargers and they have been great performers. I also just ordered a Turnigy 6 after seeing Dave's review.My solution to getting PSU's cheaply has been to hoard any high quality power supplies that I stumble upon. Ones that come from quality brands or professional equipment. I have a box full with all manner or current and voltage specs. I asked my office colleagues to save any power supplies from IT kit disposal. Compaq LCD panels use a lovely quality 12v 5A compact SMPSU. I suggest others talk to their disposals officer or IT support team and see if they will save you the power supplies from obsolete kit. On one occasion I managed to buy three new Radio Spares branded power supplies on ebay, rated at 9V 3A ......they cost me GBP3 each and are superb quality. On another occasion I bought a box of 140 (yes 140) 110-240v to 5V@1A USB chargers/power supplies from a Farnell/CPC ebay disposals outlet for GBP9 ($14) for the box fullThe reason they sold so cheap....they did not have the mains input plug adapter which is sold separately. Found the PSU on Farnells web site....UK plug part was GBP1.29 each....bought a load of them. The PSU is a FRIWO brand unit, with UK and German approvals. It uses a custom switching controller and is excellent quality. I gave loads away to colleagues to replace cheap Chinese 5V USB chargers that they had been using.Fraser

author: rollatorwieltje
author_rank: Unknown
timestamp: December 16, 2012, 10:13:30 am
content: I had a cheap Chinese power brick that caught fire under a bed... It was part of a cheap LED string with the power brick attached. The 230V input lead was not physically held in placeat all. So obviously at some point the copper went and caused an intermittent short, but not enough to pop the 16A fuse.Luckily someone was in the room when it happened, so the fire was limited to a charred power brick and a very bad smell.Another 12V 5A brick I received from eBay was so nasty it would show up on my Rigol scope when it was turned on within +/- 2 meters. I thought the power supply I was working on was bad, but it turned out to be interference from that brick. I popped the damn thing just by drawing 5A from it. After 45 minutes the output capacitors were completely dead and the transformer was well over 100 deg C.

author: T4P
author_rank: Super Contributor
timestamp: December 16, 2012, 10:17:45 am
content: You wouldn't believe me if i told you what a new samsung LED screen (Free if not i would NEVER buy anything from them) came with,it came with a PSU so noisy that it radiated it's waves onto my table and my volt-stick would pick it up everytime i tapped the table, in fact i couldn't hear it on my speakers but it was very high frequency noise that my volt stick picked up from my speakers

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 16, 2012, 10:33:43 am
content: Quote from: T4P on December 16, 2012, 10:17:45 amI would expect the output of any non-earthed SMPS, good or bad, to be detectable on a volt-stick, due to the weak capacitive coupling to the mains input.

author: T4P
author_rank: Super Contributor
timestamp: December 16, 2012, 10:36:07 am
content: Quote from: mikeselectricstuff on December 16, 2012, 10:33:43 amTrue to behold but my other non-earthed PSU my fujitsu laptop uses is not detectable on a volt-stick

author: M0BSW
author_rank: Frequent Contributor
timestamp: December 16, 2012, 07:38:33 pm
content: Surely the rectifier,has to be a noisey one, those parts diodes approx £1.00, the cap approx 50p,you'd be better off making your own wouldn't you, it would be a lot safer.

author: mianchen
author_rank: Regular Contributor
timestamp: December 16, 2012, 11:17:23 pm
content: I don't see why people complain so much! $1.5 is roughly £1. With this much, It's barely enough to send a first class letter within the UK. Now you get a transformer + 4 diodes and a bit of PCB shipped all the way across the globe into your hand for only £1. Bargain, I would say! Safety? You might need to pay a bit extra for it. Can't complain for what you haven't paid for, can you?

author: tom66
author_rank: Super Contributor
timestamp: December 16, 2012, 11:22:22 pm
content: It's pretty hard to screw up making an iron core transformer and make it unsafe. The core has a minimum size, or it won't work (it'll just burn from too little inductance I guess.) And if you have a certain core size, you can easily space the primary and secondary apart. Safe.For a quid, it's bloody good. Unlikely to do its rated current and might fail after a year or so. But heh, it's only going to add a bit more to landfill.

author: Zero999
author_rank: Super Contributor
timestamp: December 16, 2012, 11:39:46 pm
content: Quote from: mariush on December 16, 2012, 01:02:01 amI don't know what makes you say that. It looks more like a transformer with a switch connecting the secondary to different taps and the usual rectifier and capacitor combination.

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 17, 2012, 12:55:26 am
content: I picked up a box (25~) of 16v 2.5a ac wall warts from my old work, best thing i ever did! ac->dc is easy with smps, but they're almost never isolated; these on the other hand all are because they're just transformers.They were used with small ups/power supplys keeping a float voltage on the battery, and providing transistor outputs for low battery and input fail

author: mariush
author_rank: Super Contributor
timestamp: December 17, 2012, 02:50:52 am
content: Quote from: Hero999 on December 16, 2012, 11:39:46 pmThat quote is about ANOTHER adapter i have on my desk, not the one that I attached pictures of.Here, posting picture with it to prevent any further confusion... I wanted to test it out and post a thread with it but whatever:

author: amyk
author_rank: Super Contributor
timestamp: December 17, 2012, 08:44:38 am
content: That one doesn't look too bad, it seems at least they separated the primary/secondary quite cleanly.

author: tom66
author_rank: Super Contributor
timestamp: December 17, 2012, 08:48:01 am
content: No EMI filteringNo fuseInsufficient output capacitorWhat's the bicolor LED for??

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 17, 2012, 10:07:26 am
content: Quote from: tom66 on December 17, 2012, 08:48:01 amthe fuse is probably a very necked down track on the back.

author: Neilm
author_rank: Super Contributor
timestamp: December 17, 2012, 07:36:21 pm
content: Quote from: tom66 on December 17, 2012, 08:48:01 amYou don't actually need EMI filtering - it can pass with out any.Might do - but less likely than the world ending this year. (Disclaimer - if the world does end this year I still want to see the unit that passes.)

author: tom66
author_rank: Super Contributor
timestamp: December 17, 2012, 08:01:54 pm
content: I opened up a CE certified DVD player and its line filter consisted of a pi filter (capacitor, inductor, capacitor.) It only used 8W. So I think China could get away with adapters which are low emi with very little extra work.

author: mariush
author_rank: Super Contributor
timestamp: December 17, 2012, 08:14:55 pm
content: Quote from: peter.mitchell on December 17, 2012, 10:07:26 amBingo. A thin "/\/\/\/\/\" trace on the pcb.Just finished my constant current load... goes up to about 0.8A @ 5v and 1.5A @ 15v so should be fine to check this adapter.I only plugged it for a few seconds and the led was light green. No load, probably it changes color when there's some load, I'm not sure... will test it tomorrow morning on daylight.I'll test the capacitors as well, the output cap. is 20uF @ 10v.. not a standard value. I'll have to see with my esr meter and my multimeter the specs.I also want to experiment and see how and if modding it with a bridge rectifier and a bigger primary cap makes it handle more load... I don't think 2.2uF is enough of an energy storage considering it's half wave rectified, so I'm curious to see how the output looks. Then I'm probably going change the output capacitor to a 100uF 16v capacitor, I think this would be enough for better filtering but I'll have to see.Right now i'm almost sure it won't even handle 0.5A.. I'd be pleasantly surprised if it does.

author: Razor512
author_rank: Regular Contributor
timestamp: December 18, 2012, 05:13:39 pm
content: sry wrong thread

author: rollatorwieltje
author_rank: Unknown
timestamp: December 18, 2012, 06:01:42 pm
content: Quote from: tom66 on December 17, 2012, 08:01:54 pmCE is not a certification, it's just a mark that manufacturers put on their products to indicate the product complies with European regulations. It does not mean the product was actually tested and certified.

author: tom66
author_rank: Super Contributor
timestamp: December 18, 2012, 06:22:00 pm
content: Quote from: rollatorwieltje on December 18, 2012, 06:01:42 pmGood point -- it was sold in Argos under the "Bush" name, so I'd expect it to be compliant. However... it is just random junk imported from China.

author: mariush
author_rank: Super Contributor
timestamp: December 18, 2012, 06:33:23 pm
content: But even if the logo is the first, there's no actual guarantee.By the way, tested the adapter in the pictures above.. it's not as bad as Mike's usb hub adapter, but it still can barely do 5v+ @ 350mA by itself. With some mods, I managed to get it to do somewhat stable 4.6-4.8v @ about 420mA. Couldn't get it to do 500mA as it says on the label. I'll make a thread on it after the video I made gets uploaded to youtube.

author: Spikee
author_rank: Frequent Contributor
timestamp: December 18, 2012, 06:49:19 pm
content: So just put my 5V 2A SF-789 adapter on my dummy load.Voltage dropped to 2.5V and around 2A and it worked like 10 secondsAlso China approved symbol =) .Before:https://dl.dropbox.com/u/100819959/blow%20up%20psu/2012-12-18%2018.22.00.jpghttps://dl.dropbox.com/u/100819959/blow%20up%20psu/2012-12-18%2018.22.37.jpgAfter:https://dl.dropbox.com/u/100819959/blow%20up%20psu/2012-12-18%2019.23.40.jpghttps://dl.dropbox.com/u/100819959/blow%20up%20psu/2012-12-18%2019.24.12.jpghttps://dl.dropbox.com/u/100819959/blow%20up%20psu/2012-12-18%2019.24.34.jpgResult:Magic smoke is freeThe fuse tripped on the 230V line so all the light / power was gone.Cost:Like 3.5$ on ebay and 10 seconds to magic smoke.

author: tom66
author_rank: Super Contributor
timestamp: December 18, 2012, 09:48:54 pm
content: Looks like the fet failed short burning the resistor. But since it probably had a drain-gate short, looks like it killed the turn-off current limit transistor. Needs a heatsink and it might last, that is, if the transformer were bigger, primary cap were bigger, and the current limit were reduced, it may work..... but by time all of those changes had been made a PWM IC would probably cost less.

author: Razor512
author_rank: Regular Contributor
timestamp: December 19, 2012, 01:51:46 am
content: those pics remind me of something that happened to a friend of mine, they purchased an expensive microwave and when it failed, they had it repaired. The repair simply involved the person doing it soldering some wire across the area where a fuse went (it fixed the problem until the unit gave out some smoke a few month later (at which point I looked at it because they had it in their basement) and a wire leading to the transmitter thing was melted (but the wire used to bridge the fuse looked just fineI wish I had taken pictures.I just got an idea for a cool invention (A non-resettable fuse that never burns or blows out... (huge surge... no problem, you can be sure the fuse will still pass the continuity test

author: mariush
author_rank: Super Contributor
timestamp: December 19, 2012, 02:18:41 am
content: Ok, I was gonna post a new thread but screw it, not sure it's worth a new thread:Here's the $1.67 "Our Future" usb ac-dc power adapter from Dino Directhttp://www.dinodirect.com/eu-plug-usb-ac-dc-power.htmland here's me playing around with it, testing it with a constant current load and changing stuff in it to see if it can do better (be gentle with me, it's my first attempt of reviewing stuff and making video like this):Short story... the scope sees 5.6-5.9v at up to 200mA, then it slowly goes down to about 5.2-5.3v at 300mA ... this is with about 400mV ripple. After that, the ripple goes above 600mV, at about 360mA it already has a Vpp of about 1.22vLed is green up to about 100mA, goes red above a value around 100mA.One of the AC wires got loose after pulling out the pcb about 4-5 times (got loose during recording, but I pulled out the pcb several times before the video to snap pictures)It's not obvious from the pictures but R10 is barely soldered in place, one of the leads is basically soldered only on on side.After changing the output cap to a 820uF one and the input cap to a 4.7uF one, it was stable up to about 420mA, with relatively low Vpp... but it can't do more.

author: SeanB
author_rank: Super Contributor
timestamp: December 19, 2012, 04:15:13 am
content: Razor, I have seen that fuse used to do fault finding....... Pole fuse blows, so metro arctrician comes out, puts pole up and removes subs fuse (100A) and replaces it. Pole up and turn- pop. Out comes the fuse and a M12 bolt and nut replace it. Up again and in, HUMMMMM, street wiring starts to sag on the pole and ground starts smoking, stops half way through lawn. Fuse out and he starts digging to find the cable - nicked and got water in. Scotchcasted and new fuse and he was gone, job done........

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 28, 2012, 01:43:58 pm
content: This wall wart looks like an evolution of the one just posted:http://www.ebay.com/itm/Micro-USB-Home-Wall-Charger-for-Motorola-Droid-X-2-X2-3-MB870-Milestone-/200857006464?pt=PDA_Accessories&hash=item2ec402b180input left, output right, accidentally broke the neutral wire when pulling it apart.its got a fuse (little glass one) under the heatshrink, full wave rectification on the input, 2x 4.7uf 400v caps on the input (105 to -40, yeah, right, changX brand))it's got pretty good HV separation (depending on the transformer), but the soldering lets it down a lot, a diode on the output side isn't even soldered on one legthe link in the corner confuses me, the trace breaks, and the link joins it, but it doesn't jump any traces or anything, i have no idea why its there.

author: orbiter
author_rank: Frequent Contributor
timestamp: December 28, 2012, 02:21:11 pm
content: Did a video on one of these a while back... They're not good.

author: SeanB
author_rank: Super Contributor
timestamp: December 28, 2012, 03:46:48 pm
content: That was killed by overvoltage, seen similar one a phone supply when neutral in supply was nicked and mains went to 300V plus.

author: UPI
author_rank: Regular Contributor
timestamp: January 06, 2013, 02:00:30 am
content: 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

author: marshallh
author_rank: Unknown
timestamp: January 06, 2013, 03:24:26 am
content: Check out allelectronics' stock of NOS dc adapters.http://www.allelectronics.com/make-a-store/category/480/Power-Supplies/1.htmlI have a 12V, 5A supply that I bought new for $20. It works well, used it for running a high-draw FPGA board.Date code is late 2007.

author: LEECH666
author_rank: Frequent Contributor
timestamp: January 06, 2013, 06:05:11 pm
content: Quote from: mariush on December 18, 2012, 06:33:23 pmI thought "China Export" was just us (i.e. western countries) making fun of a faked CE sign, but the picture you posted makes it look like it's some sort of official logo ...I am confused, is China Export a real logo, or just a poor attempt to fake the CE Mark?

author: JoannaK
author_rank: Frequent Contributor
timestamp: January 06, 2013, 07:56:18 pm
content: When one considers how lousy the QC can be on as simple items as multimeter leads.. I purchased these to go with my ESR-meter, and while all parts are included, I'd thend to think that whoever those put together was a bit too hasty. IMHO they should relabel this one as a 'kit' ..http://diytao.blogspot.fi/2013/01/review-cheap-and-broken-multimeter-test.html

author: UPI
author_rank: Regular Contributor
timestamp: January 06, 2013, 11:48:23 pm
content: In the search for a reliable, safe and relatively low noise power supply, I have ordered a DVE brand 12V 3A supply.I have seen DVE brand supplies on several OEM applications over the years. Hopefully that says something good about their construction.DVE DSA-0421S-12 2 36 12V 3A Adapter with 5.5 x 2.5 mm straight barrel connector.http://www.ebay.com/itm/230855859362?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649We will see.

author: IanB
author_rank: Super Contributor
timestamp: January 07, 2013, 02:36:07 am
content: Quote from: mikeselectricstuff on December 16, 2012, 10:33:43 amIndeed. My iPhone lights up volt-sticks like a Christmas tree when plugged into the charger. But then I guess it's much better for volt-sticks to give a false positive indication than a false negative...

author: lhc
author_rank: Contributor
timestamp: January 10, 2013, 08:57:14 pm
content: Mean Well makes quality adapters if somebody is looking for one.

author: UPI
author_rank: Regular Contributor
timestamp: January 10, 2013, 09:45:10 pm
content: Quote from: lhc on January 10, 2013, 08:57:14 pmThanks, 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.

author: TerraHertz
author_rank: Super Contributor
timestamp: July 15, 2013, 02:11:09 pm
content: Is this the first death by iPhone charger?http://www.zerohedge.com/news/2013-07-15/ilectricchair-woman-electrocuted-death-her-charging-iphoneThe iLectricChair: Woman Electrocuted To Death By Her Charging iPhoneIf this happens too many times, the iCloud (tm) is going to need some PR reworking.

author: free_electron
author_rank: Super Contributor
timestamp: July 15, 2013, 04:01:38 pm
content: my 5$ bet says she was using an aftermarket charger , which surged, shorted out across the HV/LV path and killed her...

author: saturation
author_rank: Super Contributor
timestamp: July 15, 2013, 05:32:23 pm
content: 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.

author: nctnico
author_rank: Super Contributor
timestamp: July 15, 2013, 06:55:10 pm
content: 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!

author: Unknown
author_rank: Unknown
timestamp: July 15, 2013, 07:11:27 pm
content: 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.

author: c4757p
author_rank: Super Contributor
timestamp: July 15, 2013, 07:21:57 pm
content: It boggles my mind that people actually buy these things so cheap. They'repower 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?

author: Unknown
author_rank: Unknown
timestamp: July 15, 2013, 07:31:26 pm
content: Quote from: c4757p on July 15, 2013, 07:21:57 pmI 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

author: c4757p
author_rank: Super Contributor
timestamp: July 15, 2013, 07:58:05 pm
content: 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...

author: AndyC_772
author_rank: Super Contributor
timestamp: July 15, 2013, 09:08:52 pm
content: 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?

author: c4757p
author_rank: Super Contributor
timestamp: July 16, 2013, 03:45:01 am
content: Quote from: c4757p on July 15, 2013, 07:58:05 pmUpdate: 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.)

author: Unknown
author_rank: Unknown
timestamp: July 16, 2013, 06:36:17 am
content: Quote from: AndyC_772 on July 15, 2013, 09:08:52 pmI 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.

author: saturation
author_rank: Super Contributor
timestamp: July 16, 2013, 12:41:25 pm
content: 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 foreachstate. 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 shutits not as slick as the small charger, but its safer.Quote from: AndyC_772 on July 15, 2013, 09:08:52 pm

author: Psi
author_rank: Super Contributor
timestamp: July 17, 2013, 01:56:01 am
content: QuotePhase wire connected to case.There you go, question answered and thread finishedFrom memory someone on this forum actually found that when inspecting some device they bought form china before powering it up.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: July 17, 2013, 05:24:32 am
content: Quote from: UPI on January 06, 2013, 02:00:30 amIf 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).

author: Phaedrus
author_rank: Frequent Contributor
timestamp: July 17, 2013, 05:51:59 am
content: 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 USretailebay 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.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: July 17, 2013, 07:25:14 am
content: Quote from: Phaedrus on July 17, 2013, 05:51:59 amNice teardown, I wouldn't be surprised ifthe ripple was even higher than 300mV. NO filter caps at all is a first for me.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: July 17, 2013, 07:30:56 am
content: 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=123So 200mV, 300mV, even 400mV... That's bad, but it can't compete with the king.

author: amyk
author_rank: Super Contributor
timestamp: July 17, 2013, 12:35:40 pm
content: Quote from: Phaedrus on July 17, 2013, 05:51:59 amSBL1640CT. 16A.QuoteMy guess is they ran out of parts. Ditto for the missing 12V caps.Leadman's specfor 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.htmIt'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.

author: tom66
author_rank: Super Contributor
timestamp: July 17, 2013, 12:47:12 pm
content: 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.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: July 17, 2013, 02:47:18 pm
content: 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...

author: Phaedrus
author_rank: Frequent Contributor
timestamp: July 17, 2013, 02:53:13 pm
content: Quote from: PedroDaGr8 on July 17, 2013, 05:24:32 amSilverstone 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).

author: saturation
author_rank: Super Contributor
timestamp: July 17, 2013, 03:49:28 pm
content: 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?Quote from: Phaedrus on July 17, 2013, 02:53:13 pm

author: Phaedrus
author_rank: Frequent Contributor
timestamp: July 17, 2013, 04:18:08 pm
content: 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.

author: redtails
author_rank: Contributor
timestamp: July 18, 2013, 11:53:47 am
content: @PhaedrusI'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

author: saturation
author_rank: Super Contributor
timestamp: July 18, 2013, 01:33:55 pm
content: FWIW if you think you have a fake safety seal you can check with certifier online to see if they device you have was indeed tested. For example, TUV:http://tuvamerica.com/tools/clientlists/certs.cfmNow the bigger problem is counterfeit. The 'real' device could be certified, but the cloner could simply copy the decal and paste it on a substandard product, so its important to buy it from known sources to trace its pedigree or do a teardown if you know electronics ordo the key safety tests yourself. e.g. leakage current, grounding etc.,

author: Phaedrus
author_rank: Frequent Contributor
timestamp: July 18, 2013, 02:37:35 pm
content: There's also the case where a normally decent company makes a device that they're "pretty sure" meets a safety certification, but they don't want to spend however many thousand dollars to actually certify it. So they just slap the logo on there anyway. That happens quite a bit in the PSU market as well.