Phones, MP3 players, designer bags, artwork, money…. anything with value will bring out the counterfeiters looking to make a quick buck. Sometimes the product being counterfeited isn’t even necessarily expensive. For example, an Apple iPad Charger. [Ken Shirriff] got a hold of a counterfeit iPad Charger, took it apart, and did some testing.
So why would someone buy a counterfeit product? To save some money! The counterfeits are usually cheaper to reel the potential buyer in thinking they are getting a deal. In this case, the Apple product costs $19 and the knock-off is $3, that’s a huge difference.
A charger has one function; take household AC voltage and convert it to the 5v DC the device can use. Ken measured a few aspects of the electrical output of these two chargers. The left graph below is the Apple charger and the right is the counterfeit. The yellow lines show the voltage output. The Apple’s is narrow and flat and the counterfeit’s has a huge amount of noise. [Ken] actually had to change the scale on the ‘scope when measuring the counterfeit’s voltage so it is actually twice as bad as it looks visually. The orange lines show the frequency spectrum of the output. Lower is better. Overall, the counterfeit output is much higher with a consistent spike at the switching frequency.
[Ken’s] article is extremely detailed and contains a lot of photos of inside both chargers so head over and check it out. You’ll be able to see where the knock-off cut corners to keep the price down. If you are interested in more counterfeit Apple chargers, check out the investigation that the Raspberry Pi Foundation did.
What’s in a real charger: http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html
Why is there not a “best” design that can take AC and output 5v at 2A? And why isn’t everyone using that design? From an engineering standpoint, it would seem that it would be possible to quantify the performance and even include the cost of the parts and create an optimal design. If everyone used that design, the cost for those parts would plummet even further. You could still brand your products and charge more for that brand, but you would no longer have to re-engineer the wheel.
Probably patents.
It has nothing to do with patents. Anyone can make a switching power supply. The reason the cheap ones are so shitty is they lack any kind of filtering, and use the lowest quality transformers (yes switching power supplies have transformers) and transistors. Adding extra filters and using better components costs more, plain and simple.
Yes, it has to do with patents, otherwise everyone would be using Dart’s technology. http://finsix.com/dart/
Besides the cost engineering standpoint, I believe there actually a large number of patents that could curb the decisions of companies (along with cost and other factors). Here’s a relevant patent: http://www.google.com/patents/US7924578
It describes the tank circuit used in the current Apple chargers.
That patent being granted is total crap as the active clamp design described there has been around since the late 80’s.
AMS
Much like most of Apple’s patents, but that never stopped them…
Same could be said about engine firing order http://en.wikipedia.org/wiki/Firing_order and engines in general.
One word. Illuminati.
Maybe aliens?
The ‘best design’ relies on what you are trying to do. The aim is to charge a battery but what type? what other electronics in the phone will be effected? How fast do you charge the phone? What frequency roll off characteristics do you want for the output voltage. Some designs are RLC circuits some RC in design, these will effect material costs and circuit design. Some filters are much faster to attenuate frequencies but lead to ripples and vice versa etc. Transformers also have operating sweet spots dont want to push it too hard for a small transformer but also don’t want to build a large cumbersome design. …. All those things and more, I am sure.
Fred, that’s an interesting question. The chip manufacturers have reference designs for chargers that you can download. But because of engineering tradeoffs, there isn’t one best design. For instance, one company might be willing to spend a couple dollars more to add more filtering, use expensive polymer capacitors, be more efficient under no-load conditions, fit into a smaller package, adding over-temperature and over-voltage protection, etc. Another company might be more interested in saving money even if the quality is lower. Another company might not care if the charger is bigger. So it’s unlikely one design will satisfy everyone.
Cost.
For Chinese no-name manufacturer, optimal design is “works for a few weeks, costs absolutely minimum”. Reputable brands may require other things, like, “doesn’t burn down the house”.
Freddy, Don’t be a Communist my boy. That’s not fashionable.
Probably the only case where Apple is gouging their customers just a little instead of a huge whopping amount. It would be interesting to know if there’s some mid-range ($3<works ok<$19) charger out there that's not a rip-off or a fire hazard.
Bad filtering because of bad caps maybe? There are counterfeit caps from China that have big tolerances for everything. It would be fun if he tried to change some of the caps and do the measurements again.
Don’t know a whole lot about circuit design but what is the big deal if the knockoff charger has “dirty” voltage? Doesn’t the phone’s power board have a regulator or something to prevent voltage spikes?
Depending on the size of the spikes, you may go over the ratings for the next components – caps, LDO regulators,etc. Bypass caps are there to keep DC supplies clean, it doesn’t help if your power supply is injecting crud onto the DC. Some chips have their I/O levels impacted by this noise.
It all adds up to degraded performance and potential to shorten the life of the connected device.
The design of the apple charger says it targets a “max 100mV ripple” fine! But if the fake one ripples between 4.5 and 5.4V (900mV) that’s just as good for charging purposes as 5.0-5.1V.
Max 100mV ripple at *5 volts*. Undervoltage is also bad!
Exactly!
Every month or so someone comes up with a new “comparison” between a fake and a real charger and points at the huge amount of noise on the output.
The thing is, if all you’re doing is charging a battery, then a HUGE amount of noise is entirely acceptable.
Now that’s not entirely true: The LIPO charging in an ipad/iphone/other-phone is done using a chip, and they are usually made for USB carging. They are specified to work up to input voltages of (usually) 5.5V. So as long as the “fake” charger stays below the 5.5V, even in the peaks, all is fine.
From the article: “the Apple charger has much more insulation”, well good for it. But was that necessary? Apple might have crammed a bunch of components together into a (too) small space, and then requires insulation tape between them to keep things safe. The fake one might just use more modern components so that the housing is less crammed-to-the-brim, and then can suffice with just air as insulation.
I’m not saying that the fake charger IS safe, just that we see way too many of these “fake-vs-real” comparisons from people who technobabble enough to convince the masses.
If you design a circuit straight-on, you will end up with a bunch of components for each function. Sometimes a smart guy comes along and manages to combine a bunch of functions into a single component. Thereby simplifying the circuit and reducing production costs. Maybe apple did the straight-on design, and the chinese managed to find an “optimized” circuit somewhere. Or maybe they used a better chip?
On the other hand, it seems that this chinese charger did have way too little clearance between the high voltage and the low-voltage side.
A huge amount of noise is not acceptable if it interferes with my other equipment.
I bought an IR extender once and it made terrible noise in my HF receiver. It took me a a while to track it down to the IR extender. I opened it up and found an empty spot marked C2; I put a .01uF cap on there and it got quiet.
Dirty power is the electronic equivalent of drinking dirty water, you may be fine, you may shit blood for a week, whereas with clean water your always fine.
the transformer in the fake looks like the tickler transformer used in older tv and monitors.
I would be more interested in a hack testing what it takes to clean fake chargers output. Is it only cheap shitty chinese caps? Maybe adding 2-4 $0.2 components could transform it into something usable.
The fake chargers are security hazards anyway, what would be the point?
What do you mean by security hazard?
(I agree with there being no point when the LV and HV parts have insufficient separation…)
A charger could contain a full USB host implementation (rather than just a power supply) and attack the device over USB, trying to sync to it or exploit bugs in its USB stack or whatever.
I think this talk is the one that got a lot of press attention: http://www.blackhat.com/us-13/briefings.html#Lau
“A boy of seven was killed by a counterfeit Gameboy charger while on holiday in Thailand, an inquest heard yesterday. Connor O’Keeffe was found on a hotel room floor in Phuket still holding the wires of the charger after he was electrocuted in December last year.”
Meh, the knockoff still gets the job done just fine. Is it really worth spending 533% more just to know your power supply makes a bit less noise? This is like putting synthetic oil in your car. Yes, the synthetic oil has better properties, but it isn’t going to make much difference unless you are driving around the North Pole.
The dissection and testing is still interesting, though.
the big issue is not noise, that is at most an annoyance when your device stops working.
The issue is safety, the knock-offs may electrocute you or catch fire
So it more like replacing a sticker that says airbag with an actual airbag
So how often do you hear that happen? I don’t recall seeing any news item about such an event, which is weird since it must happen sometime you think, and then somebody would be suing someone else surely.
Addendim: When I say I did not see any such newsitem I exclude the boeings and iphones or galaxies catching fire and such. I refer to the chinese branded causes.
Google iPhone deaths. The ones I have read about have all been with fake chargers.
Yes, cheap out on a charger and instead choose to put your $500+ smartphone in danger of getting fried. Good job with the cost-benefit analysis, pal. /s
What an amazing writeup and excellent photos. Ken must have spent an incredible amount of time to make something so amazing.
It is an interesting read, but as others have said, he does not go into the consequences of this ‘more noise’ thing, does it really matter how clean your charging voltage is, and how much of that is absorbed by charging the battery? (a battery acts/is like a big capacitor too)
Another thing that struck me is that he appears to misidentify the promary and secondary in the pics/story. The primary hase the most windings as the voltage is much higher there. The secondary has much less windings but much thicker wire to handle the current.
nope, I spoke too soon. He identifies the prImary and secondary correctly, I should have read more carefully… :(
(also HaD, why don’t I get firefoxs spell-check thingy here? It’s obvious I need it…)
The battery acts like a capacitor, yes, but it is not charged by the external “charger” which is technically a non-current limited power supply. All the charging logic is inside the phone, and that circuit might not like the spikes.
Forget arguments about noise – fake chargers could burn your house down. or electrocute you or your kids.
Kids are easy to make, but I just got my workshop sorted. Losing that would be painful.
So, there are millions of ‘fake’ chargers out there, can you show us a few housefires started by these ‘dangerous’ chargers? (as in other stuff that caught fire, not just a blackened charger) In other words, please quantify the risk you tout.
In my humble opinion, you are just one smidgen above the ‘think about the children’ herd. Oh wait, you included ‘your kids’…
6% of electrical fires are caused by transformers and power supplies:
http://www.nfpa.org/~/media/Files/Research/Fact%20sheets/HomeElectricalFiresFactSheet.pdf
But depends on person whether you consider this a large risk, considering how many of the fires are due to wiring..
If you bothered to read the article before attacking other commenters you’d note that the author linked to two people who have been electrocuted by fake chargers (one of which died). I’m sure someone who was as interested in the matter as you could find plenty more.
“Electrocution is death caused by electric shock, either accidental or deliberate. The word is derived from “electro” and “execution”.”
Well done. That doesn’t change my point though, and I’m quite sure that any person here is capable of understanding what I meant.
Yeah. In one month last year those two incidents were in the news. Why two in one month, and none we hear about in the 12months before or after? What else was going on? Leaky roof, rain? We don’t know.
There was a rather publicised accident in Poland where woman bought shitty chinese Nokia charger at a cellphone thrift store. That charger malfunctioned while she was talking on the phone and charging at the same time. This resulted in an explosion that took half of her face off :(. Cellphone shop liquidated promptly, owner moved to another town.
So thats why I can get 4 chargers shipped from China for $15 including shipping.
The problem is its not just fires but damage to equipment caused by junk chargers.
I actually damaged a phone by plugging it into one of the fake chargers, won’t charge any more.
The problem with cheap chargers is 3 fold:
1) excess noise on the charger output can stop the device being charged from working properly or damage it.
2) excess noise generated by the charger can interfere with other equipment through radiated and conducted emissions.
3) a badly designed charger can be unsafe and is potential safety hazard from fire or electrocution.
Most if not all cheap knockoff chargers of the kind discussed here are not tested to see if they meet local EMC/EMI or electrical safety standards and so do not have certification for use on your local power network.
Your cheap, non-compliant, knockoff charger will not be so cheap after it burns your house down and your insurance company refuses to pay because the charger was not certified for use in your locality.
Many cheap device makers go as far as putting fake compliance marks on their products. Real compliance marks can be traced through the issuing body, eg UL or proven by the manufacturer in the form of a certificate of compliance from the test lab.
This is part of the reason the Apple charger costs more than a cheap knockoff.
I like to keep the original chargers as travel chargers. At home, I use an old cheap PC AT PSU with five USB ports to charge my stuff. Much bulkier but it’s able to supply more than 20A of clean regulated 5v power. Now I’m gonna use its 12v line to power a small 30w audio amplifier.
Old computer PSUs = gold
Your USB-wire on fire when the plug craps out and shorts out and your PSU keeps delivering 20A into the short. Not gold, not happy.
Maybe we’ll see a trend of chargers in clear casings so it would be easy to see the build quality?
I think that’s a fantastic idea for OEM’s to minimize poor copies. Knockoffs will happen, but this may cause the copiers to gravitate toward better quality components and eroding their profits. Maybe even making comparable chargers at a more reasonable (lower) profit margin.
There is a simple option to build a high-quality charger cheaply. A good quality, safe 5-volt wall wart supply can often be purchased for a couple bucks from a thrift store or PC recycler. iPhones and iPads depend on a couple voltage dividers to provide certain voltages on the USB data lines to know how much current they may draw. Add four resistors to a hefty 5-volt wall wart and you have a cheap, safe, reliable charger. I’ve been using the charger shown in the linked article for 10 months with iPhones 4 & 5 and an ipad with excellent results.
http://digital-diy.com/forum/electronics-projects/iphone-ipad-charger-t2819.html
Thanks for all the comments. Noisy power does make a difference. The most visible effect is it makes touchscreens erratic in many cases. (See Amazon reviews of cheap chargers for examples.) But noisy power is also adding stress and heat to the components in your phone. To quote the capacitor datasheet: “When excessive ripple current is applied, internal heat increases and reduces the lifetime.”
Mike Lu: Clear chargers would be pretty cool, but I don’t think Apple would go for that look :-)
rewolff: no.
rasz_pl: you ask what would make the cheap chargers better. Larger and better capacitors would probably be the biggest improvement. Most of them don’t use a controller chip, but just a simple RCC circuit, so the regulation is still going to be bad. (The controller chip in the iPad charger is surprisingly complex. It has totally different regulation techniques for high vs low vs no load. And it is monitoring multiple voltages and currents to react immediately to changes in input or output voltage. This gives you better regulation, lower power consumption, and less radiated noise than a simple circuit.) But pretty much all the components in the cheap chargers are worse – the diodes, the transistor, the capacitors, the transformer. (They probably can’t mess up the resistors too badly.)
Funny thing is, Apple *did* make stuff in (colored) clear cases 15 years ago or so. But I do think it’s probably going to be the trustworthy third party manufacturers doing it first.
I had a similar run in with a counterfeit apple charger for ipods/ iphones
http://wtfmoogle.com/?p=3626 check it out. The build quality scares me.
Power supplies have probably always been ground zero in the relentless drive to make things cheap, at the expense of service life, safety, and reliability. For example, transformerless mains-connected radios (and later TV’s) that were the norm since the era of the “All American Five” radio from the mid 1930’s (The Great Depression). It isn’t a new Chinese thing, it’s an old American thing.
Our landfills overflow with recent consumer electronics that have died from bad electrolytic capacitors. On the positive side, both of my desktops have recent high-res LCD displays that I obtained for free from the curb. Repaired them myself with <$10 of top quality Japanese electrolytics.
It's silly to try to save $20 on a charger for a $500 phone / tablet / laptop. If you think Apple is ripping you off, check out the prices of OEM supplies from Mouser / Digikey / Element 14, etc.
I’ll just leave this here:
http://hackcorrelation.blogspot.de/2014/05/building-cheap-usb-power-measurement.html
How to do your own measurements at home and the caveats, but I still believe cheap chargers are bad.
I think because of one such charger my Motorola Razr is not charging anymore when using some cheap chargers. Probably some large voltage degraded a capacitor on the input rail.
Anybody have verified recommendations for high quality, reliable 5v USB chargers (both home and auto)? In taking a handful of my own apart (they usually fail due to the cheap nature/poor design of the USB micro plug… sigh… ) and inspecting the internals, I’ve found that Seido seems to have the best visual build quality thus far, but then they’re the only namebrand charger in the mix for me, the rest I’ve done tear-downs on have been a variety of no-names. Due to costs, I’ve yet to just buy a mess of different brands for sake of disemboweling them. I’d be interested to hear recommendations…
The Nokia AC-10x is often recommended for the Pi as a low-cost but reliable option (or was in the past, I haven’t kept up to date recently). I have yet to have a problem with one myself. I’ve never checked what the output actually looks like though.
I see that [Ken Shirriff] also did an article in 2012 comparing noise, efficiency, etc… among household 5v chargers: http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html , which doesn’t seem to have been featured here on HAD (at least it doesn’t seem to come up when I search for it). I would love to see that turned into a full post!
Most useful comparo I’ve ever read about wall chargers. Now I’m hoping he’ll do one on car chargers!
I’ve torn down the fake Samsung 2A chargers; they are blatant fakes as the design and parts simply won’t support 2A of current. Plus the PCB creepage distances do not meet safety standards, so these are very dangerous if they get wet. These things are all over Amazon and eBay and it’s hard find a reputable vendor; the easy way to get a reliable 2A charger is to buy one from Digi-Key or Mouser where they cost as little as $8 (plus shipping), and you get a product that meets the specs and safety standards each and every time.
Hello, this Samsung USB charger is purchased in store, not on Ebay, it is fake or original ?
http://rodi.sk/blog/samsung-eta-u90ewe-001.html
Thanks
It looks like the design is of typical cheap chargers, because they are the ones using mostly DIP components. I would check the output noise with an oscilloscope and how it handles load. I doubt it can do 2A as I have several of those with the same design (no-name) and they drop voltage sharply at 1A or less.
Nevertheless, it might not be fake, maybe Samsung contracted a cheap house to do the units. However, since I doubt it can do 2A I would bet it’s fake.