I my self have been planning to get one of those Apple chargers!
I have a Motorola Smartphone, And the charger that was came in the box works very well at 230V AC(I got the phone in India) and when i charge it on 110V(Here in the US) the touchscreen acts all funky! I even got an original US Motorola charger they sold at the Verizon Store and that charger has the same problem too..... Motorola needs to invest some more design resources in their charger design!
Nice write up. But can I just point out that the secondary winding in the Chinese knock off is not bare un-insulated copper, rather enamelled copper - standard practice for any kind of electromagnetic type component be it transformer, inductor, motor etc.if it were plain copper the windings would all short out and the transformer would fail to work at all.
I strongly feel that Ken knows that the secondary in the knock-off is insulated with enamel. I think he was trying to point out the insubstantial insulation rather than complete lack. Perhaps he will change the wording to satisfy the pedants.
He keeps talking bout the so called 'flyback' transformer', yet both circuit examples use standard high frequency transformers - not flyback types. The high frequency transformers used here create square waves and the frequency and pulse width are controlled by the IC to maintain the output of the high frequency transformer at the correct level of high frequency AC that produces the correct rectified voltage at the output. The Apple unit has the extra parts for superior control. A flyback transformer is to make a ramped sawtooth wave for electron beam control in raster scan television, where the beam passes across the screen and is intensity modulated(made brighter and dimmer) to wtite the image line by line. At the end of each scan, the pulse from the flyback transformer makes the beam 'fly back' to the start of the next line. http://en.wikipedia.org/wiki/Flyback_transformer
May 11, 2014 at 6:00 AM
Anonymous said...
I wish you had a similar overview on apple batteries!
aurizon: The circuits do use flyback transformers. Please read the first paragraph of the Wikipedia article you referenced. Flyback transformers are used in old TVs and are also used in low-power switching power supplies. What you describe is a forward converter, which is a different power supply topology. There's a nice diagram here of different topologies. Also see footnote 2 of my article for more information.
mangodan: Yes, there's enamel of course. I'll clarify the text.
Ken that was a fantastic post! I want to thank you for an inspiring late evening read inspiring me to wish to do as well in what I do.
-- john Sheppard
May 11, 2014 at 8:06 PM
Austin said...
I want to add that I made the mistake of buying one of the fake chargers before. The ones that I've gotten had a wierd grounding issue where the touch screen responded oddly to all my input and If I picked up a device of. Mine, it shocked me. It was a 5 pack and it did that with every charger. Never again.
May 12, 2014 at 6:51 AM
Anonymous said...
The knockoff probably generates a lot of very broad-band RF interference as well.
May 12, 2014 at 11:42 AM
brhfl said...
In discussing the ground pin, you mention that since the plug is two-prong, it does nothing. While this is true, these power bricks from Apple can also use the lengthy cable attachment instead of the direct plug. This cable does, in fact, connect that pin back to third pin ground. I always thought this was a clever design on Apple's part.
May 12, 2014 at 11:46 AM
Steven said...
How about doing a comparison with an MFi-certified charger, like from Monoprice?
May 12, 2014 at 2:23 PM
Anonymous said...
Incredible price! Any plans for teardown on lightning cables? I'm sure the Apple ones are safer, but $19?!
How much do you value your iPad? After spending several hundred dollars on the iPad, which is a quality instrument, you're going to skimp on the charger? Penny wise, pound foolish. I say give the devil his due.
This is particularly relevant when officials suspect this http://www.bbc.co.uk/news/uk-england-south-yorkshire-27371854
...was caused by a faulty charger.
Good post.
May 13, 2014 at 4:49 AM
Anonymous said...
I have a question about the weight of the two chargers.
Since the real iPad charger has more components and especially larger transformer, did you find any weight difference between the two chargers? Is this a reliable way to tell the difference of the real and fake charger?
May 13, 2014 at 5:16 AM
Anonymous said...
My wife bought a cheap charger 2 years ago for her iPad. After a short period it starting making a hissing noise and smelled of ozone. We threw it out and she bought an Apple charger instead. After reading this now I understand what it was doing and feel lucky we did not have a fire!
May 13, 2014 at 5:43 AM
Anonymous said...
Another option is to use a high quality but cheaper USB charger from Samsung or HTC which is what I have been doing for the last 2 years.
May 13, 2014 at 5:44 AM
Anonymous said...
so you're sayin the 5 chargers I just bought from china for $20 aren't good?????? .. kinda figured :-0
Very interesting post. I'd like to see the difference between Apple's 10W and the newer 12W iPad chargers.
May 13, 2014 at 7:27 AM
Anonymous said...
Can we get corrected photo links to the large photos? It's hard to see details in the article photos.
May 13, 2014 at 8:28 AM
Anonymous said...
Nice Review Ken
Clearly no NRTL or Internationally Recognized Lab actually reviewed the construction. Unfortunately some reported Counterfeit Apple Charger already cost a poor woman her life in China. http://www.scmp.com/news/china/article/1283818/woman-electrocuted-while-answering-iphone-may-have-been-using-fake?page=all
Hopefully your review can prevent further tragedies.
Hi excellent in depth reviews and thoughts on iPhone iPad and a few other chargers . Feels good to reach such technical and actual engineering stuff on the internet.
I am from India and had an iPhone 4 in the past . Indian iPhones come with a rather different iPhone charger. Not the cube one. These chargers worked fine on iPhone 4 and 4S and since it's very hot in I they worked good in these conditions . But with the iPhone 5 I experienced the issue with touchscreen interference. I had 3 iPhone 5 and had the issue with all 3 so it has to be the charger. Same thing happened with a friend of mine so it's not just my charger. Now I'm currently using te cube iPhone charger which my sister got cause her iPhone was purchased in the US . The issue doesn't happen with iPad charger cause it's no different than the one sold in the US but the Indian iPhone charger seems to be not the same as the one in US in terms of power quality. If it's possible for you to get your hands on the Indian iPhone charger please take a look at it . It really is interesting as it only happens when the iPhone draws a lot of current initially for fast charging . And it's scary !
May 13, 2014 at 12:39 PM
Anonymous said...
Ken Shirriff needs to review his blog on the ipod charger against his reference: Either the full-wave rectifier l,when the input voltage is 100Vac or 240Vac is 170Vdc to 340 Vdc or 145Vdc to 335Vdc. Ken writes "You might wonder why the DC voltage inside the power supply is so much higher than the line voltage. The DC voltage is approximately sqrt(2) times the AC voltage, since the diode charges the capacitor to the peak of the AC signal. Thus, the input of 100 to 240 volts AC is converted to a DC voltage of 145 to 345 volts internally "
May 13, 2014 at 1:29 PM
Anonymous said...
Ken Shirriff needs to review his blog on the ipod charger against his reference: Either the full-wave rectifier l,when the input voltage is 100Vac or 240Vac is 170Vdc to 340 Vdc or 145Vdc to 335Vdc. Ken writes "You might wonder why the DC voltage inside the power supply is so much higher than the line voltage. The DC voltage is approximately sqrt(2) times the AC voltage, since the diode charges the capacitor to the peak of the AC signal. Thus, the input of 100 to 240 volts AC is converted to a DC voltage of 145 to 345 volts internally "
I would love to see a comparison between the EU and US iPhone charger. The EU charger is (from what I understand) a bit smaller. The iPad charger seems to be he same, and that is logical as the plug can be exchanged, but the iPhone charger looks like a standard EU-plug, just a bit longer.
Please don't use the term High Voltage when referring to low voltage appliances. I saw that you mention this in foot notes but 600V AC is high voltage not 110-240 line voltage. The knock off iPad charger is not going to Arc Flash.
I too was a culprit of a counterfeit charger, I bought one which looked exactly like the apple one when in hospital, when I got home it got mixed up with the official ones and when plugged in one day,BOOM! It exploded off the wall game me and shock and sent sparks everywhere pand my little boy was 3ft away...
I will never buy a counterfeit charger or even use one again.
Thanks for writing up this detailed post. I was thinking of getting one of these cheap knockoffs as a spare charger, now that plan's out of the window.
I always wondered why some of the cheaper chargers for android phones made the phone act funny, especially funky behavior on the touch-screens side, now I have some idea, thanks to you.
May 14, 2014 at 8:35 AM
Anonymous said...
Thank you, Ken!
Impressive detail and thorough treatment throughout makes this a must-read, must-bookmark reference--one I will be sure keep handy to send around to too-cost-conscious owners of iThings I know intent on replacing their chargers.
"You get what you pay for" seems to be the overall message--but in this case you've given the iAudience a free lunch and much food for thought. Much appreciated.
May 14, 2014 at 11:22 AM
Comment deleted
This comment has been removed by the author.
May 14, 2014 at 9:56 PM
Anonymous said...
Excellent article. I think we could say a little more about those blue "Y" capacitors.
They come in two varieties: "Y1" and "Y2", and perhaps counter-intuitively, a Y1 cap has twice the voltage rating of a Y2. Basically, Y2's are designed for US 110V mains, while Y1s are meant for European 220-240V mains. Or, you can put two Y2's in series to give the equivalent of one Y1 In most cases, they're all that sits the user and the AC power line, so they obviously are a very special component, and have to be made as reliable as technologically possible.
"250V Y1" actually means: "This component can safely be wired between 250V AC mains and exposed metal parts accessible to the user, and will safely withstand voltage surges up to 5,000V without damage or hazard to the user."
Y2 capacitors are rated at half these voltages and are intended for 110V mains.
Voltage surges are far from uncommon on normal AC power lines. They can be caused by switching off of heavy inductive loads, lightning hitting power lines, trees falling on power poles holding both domestic and high voltage distribution cables.
In my experience, Y1 capacitors can withstand up to 10,000 Volts DC at least for short periods. (They could go higher, but past that point, sparks tend to start jumping across the leads!)
But now we come to the really nasty bit. It's not at all uncommon for unscrupulous (or just plain ignorant) power supply manufacturers to substitute ordinary DC-rated ceramic capacitors in place of the pricier Y-rated types. Most commonly you'll see a tiny brown "1,000 V DC" ceramic capacitor instead of the much thicker blue Y-rated type. (I have also seen the same types, painted blue!) A 1,000 V DC rating has a completely different meaning from "250V Y1", and the component will typically go short-circuit if you apply more than about 900V AC to it, a far from uncommon ocurrence on normal power mains.
If the voltage spike manages to kill the AC adaptor as well, that's not so bad. Not ideal, but at least the user will stop using the device. But the worst problem is that it is entirely possible for the capacitor to go short-circuit and the power supply to go on working, except that the DC output pin (or USB shell) is now live!
It's also entirely possible for the adaptor to go for years like that, until someone touches the exposed metalwork while standing on damp ground or leaning on a grounded metal sink...
Ironically, I've seen many examples of perfectly-good designs, with the correct creepage and clearance and so on, and then they go and screw it up by fitting a crap cap!
May 14, 2014 at 10:02 PM
Anonymous said...
That "redish insulating film" is not there for electrical insulating. It called "Kapton tape" and it is for heat-shielding.
How fast it charges and does it catch on fire, are pretty much the only factors that matter. I suppose if there's a potential for long term damage to the device, but on the whole, even iPads are quite nearly throw away items now. We had the same discussions years ago with power supply/power conditioners for servers and at the end of the day, spending $3500 for a state of the art power conditioner to provision a bunch of commodity servers makes no sense. Especially given that power supplies and conditioners themselves actually have a finite service life.
May 15, 2014 at 6:27 AM
Anonymous said...
Any feel for if or how power consumption and output is handled without a device connected. Including when a lightning cable is plugged in to the USB port in the charger but not pluged into a device.
IANAEE. I am not an electrical engineer, so pardon the stupidity of this question.
This post is very informative and timely for my needs. My question is related, I think. I don't want to use a cheap transformer/charger, but I do want to use existing wiring and a good-quality transformer to power iPad Minis and instead of the chargers (adapters) that come with the iPads.
I want to install 9 or 10 iPad Minis on my walls (for A/V control). I can't re-wire to provide power. I would like to use the existing Crestron (Cresnet) wiring to provide low-voltage power directly to the iPad Minis, instead of using 120V and chargers/adapters since there is no near-by power source.
The Cresnet wiring seems capable of handling the required load. From the Crestron site: "Cresnet is a simple, yet flexible 4-wire network that provides bidirectional communication and 24V power". One pair of the stranded bare copper wires is 22AWG x2 (which Crestron uses for data), and the other pair is 18 AWG x2 (which Crestron uses to power its soon-to-be-replaced wall panels). Is my assumption correct that the in-place wiring can handle the requirements of the iPad Minis?
I want to use a high-quality transformer, located at the head-end (where my existing A/V equipment is) to provide the 10w (or is it 12w?) power that the iPad Minis need. I'd use a transformer with these specs:
DC VOLTAGE 15V RATED CURRENT 10A CURRENT RANGE 0 ~ 10A RATED POWER 150W VOLTAGE ADJ. RANGE 14.3 ~ 16.5V
(See this transformer: http://www.jameco.com/Jameco/Products/ProdDS/173412.pdf)
Am I crazy, crazy stupid, just stupid, or on the right track?
Thanks in advance for your help!
May 15, 2014 at 5:01 PM
Anonymous said...
why dont they pot BOTH Chargers with Epoxy?
May 22, 2014 at 5:38 AM
Anonymous said...
I have had a cheap Amazon knock off for over two years. I'm haooy with it.
May 22, 2014 at 8:00 AM
Comment deleted
This comment has been removed by the author.
June 1, 2014 at 9:28 AM
Anonymous said...
What would be the leakage current from two 220pF Y capacitors in the iPad charger based on the voltage and frequency? When I touch the edge of the lightning connector to the ground screw on the UPS in the dark room I sometimes see tiny blue spark due to momentary spike as the capacitor equalizes to AC voltage. Can this spike cause a static like shock each time the device is touched while body is grounded.
I have an iPhone charger came with my iPhone. After reading your post, I became suspicious that it could be a counterfeit one because it had a plastic ground pin and the text on its body became unreadable after several years of usage. I cracked it open and found it's genuine! This charger came with my iPhone 4 and had an iPad charger's form factor. Surprisingly I didn't find the control IC in it. It had a second small board (about 7mm x 15mm) attached vertically to the main one. It has 3 traces joined to the main board. One of the trace connected to the gate pin of the switching MOSFET on the main board. I thought this board must function as the control IC.
June 27, 2014 at 12:51 AM
Anonymous said...
I sent your article to a newspaper, so they could accurately report on the latest death. They seem to have used it.
Thanks again for putting the effort in.
June 27, 2014 at 5:40 PM
Anonymous said...
A fantastic article, found you from The Register, very interesting read and very educating for all, surprised me just how complex a changer actually can be. Good stuff :) Simon B
July 1, 2014 at 1:22 AM
Cubytus said...
Interesting and thorough teardown. I had a look into my own counterfeit iPad charger that recently burnt, and while mine appears to follow better safety guidelines (including crepe distance and insulating fin), it wasn't up to the job eventually.
September 20, 2014 at 2:32 PM
Anonymous said...
Great post and very informative. I have a question. How would the charger handle a high frequency input or say 400Hz at 110V? Is the circuit capable of safe operation over time or would it exceed the design of any components. Thanks
Anonymous: I'd expect the charger to work at 400Hz. The first step in the charger is an AC to DC diode bridge, which shouldn't be affected by the frequency. After that point, the circuit runs off DC, and the frequency won't matter. But when you're running out of spec there aren't any guarantees, so don't blame me if something goes wrong.
For more on running power supplies at 400Hz, see this article.
Anonymous: yes, the charger consumes a small amount of power when plugged in without an iPad. The Macbook charger uses a more complex switching power supply circuit (with PFC in some models). They make it small basically by cramming stuff in there through careful design.
Firat: sure, you can translate it into Turkish. Thanks for asking. I'd be interested in seeing the Turkish article when you're done, so send me the link.
November 12, 2014 at 7:56 PM
Anonymous said...
Great info. I've changed 7 chargers in the last 7 months; so I'll take note..
But why doesn't anyone comment on the real issue - why do we need to replace an Iphone/ Ipad charger so frequently in the first place? Someone said penny wise and pound foolish - well, if your buying such a quality product which is the premium in its segment, why should the charger be of such low quality in any case? Why haven't we heard of Samsung and Blackberry users needing to change their chargers so often?
Could it be that Apple is just too greedy? They design poor chargers so that we will need to buy again? And they are clever enough to just leave a bit of gap in their clever engineering so that no one notices..?
November 18, 2014 at 10:30 PM
Anonymous said...
Have you measured leakage current between the aluminum case and earth ground while charging? Anyone report any tingling in the 120V or 240V regions?
November 19, 2014 at 6:02 PM
Anonymous said...
Hahaha, I always laugh when people who get the newest most expensive iphone buy a cheap 1 dollar charger. if you got so much money that you spend 800-1000 dollars on a phone then why not get a proper charger? Apperently the people are rather poor. Ridiculous.
"Anonymous" above complained (understandably) about having to replace AC adapters 7 times. I'd be upset, too.
That said, there's just no way that's normal. Something really bad is happening with your power, frying those adapters.
I still have every iPod/iPhone AC adapter I've ever had, and none has ever failed. (That's something like 7 or 8 in all.) Nor have I ever heard of them failing from friends or acquaintances. This just isn't some widespread problem.
Whatever the cause of the failures, it's not the build quality -- assuming you're talking about genuine Apple adapters, not counterfeit ones.
February 16, 2015 at 4:11 PM
Anonymous said...
Apple doesn't seem to care about the 80% derating rule. In products with universal input (for both US and Europe) the filtering capacitor after the bridge should have 450V voltage rating. This is the norm everybody follows, except cheap Chinese manufacturers. Apple too uses 400V.
February 19, 2015 at 3:22 PM
Mvaldez said...
Thanks for your article, very informative. I really like that you not only posted an opinion, but real facts. I have bought non-Apple cheap chargers in the past and when I opened one I realized it was different than the Apple original, I saw some of the differences you pointed out. But with your article I learned mode about that differences (specially the safety related ones). Thanks for sharing.
Regards, MV.
February 20, 2015 at 3:51 PM
Anonymous said...
Thanks for great and informative article!
I wonder if supplying a power to iPhone from any Mac has any difference comparing to wall chargers? All Macs since 2007 can add 500 mA to standard 500mA USB output for iPhone (and additional 1600mA for iPad!).
I just want to know, of the knock-off brands, which are considered the better ones. Anyone?
April 3, 2015 at 2:38 PM
Anonymous said...
Thanks for the in-depth article. I was just about to crack open my Ipad 3 10W charger to check out the innards. Now I don't have to. While these supplies are called Flyback ,Aurizon's comment about the old CRT scan circuits being the origin of the flyback designation. In those supplies the magnetic storage was primarily in the deflection yolk and the flyback pulse routed through the High Voltage transformer. These supplies have more in common with older automobile ignition systems than the CRT supplies. to answer two queries above. The leakage current through the Apple supply is about 8 microamps at 60 hz 120 VAC. while at 400 hz while the noise factor and filtering will be markedly better, the AC leakagage through the Y caps will increase to nearly 46 microamps.
May 17, 2015 at 6:38 PM
Trevor said...
Thanks,
I purchased two of these counterfeit chargers for my MacBook from eBay which is notorious for counterfeit electronic peripherals. At the time I didn't think it was counterfeit until I went through the first one in less than 3 months. It started making this "clicking" noise. So I figured maybe I burned it out or shorted it out by mistake. The second one, the cord didn't feel genius like the original. Luckily I kept the original charger that came with the MacBook and didn't throw it away. Make a long story short, the best way I can tell if a charger is real or not, is compare it with the original. If the other charger weighs less, then it more than likely is fake.
I REALLY love this series of breakdowns on the Apple chargers, etc. They not only provide a meaningful analysis of what a good component is - but make it clearer from a grand perspective - why and how these now-pedestrian, yet insanely complex devices are built the way they are. Cheers!
October 1, 2015 at 5:48 AM
ravi said...
very interesting article , never thought i would get to see the internal part of charger..thanks for sharing
1. Your use of "high voltage" versus "low voltage" isn't the right term in dealing with creepage or clearance. While there are distances between conductors the rules based solely on voltage are straightforward. I believe "primary" and "secondary" are better terms because that will indicate the requirement for isolation from the AC line.
2. The enamel coating on the cheap transformer windings needs to only stand off the turn-to-turn voltage, except at the crossover. This isn't much voltage. And a single piece of tape can easily handle the crossover. Using triple insulation is a tool, not a requirement, and there are valid reasons for using it and valid reasons for avoiding it in any specific design. And each designer may have their own preferences. While it's unquestionable that triple-insulated wire will have a higher voltage breakdown, that does not mean it's less safe.
3. Some transformers may not want to have tightly-coupled windings. In fact, flyback converters must have some substantial uncoupling to provide the primary inductance that stores energy. So using a sandwich construction may be a good design, or it may not be. It just depends on how the circuit is designed. In fact, avoiding a sandwich and intentionally separating the windings to increase inductance can be of great benefit if the flyback is designed to take advantage of that construction technique. While it does add more money, the cost is slight and doesn't reflect on the build quality or design. Most SMPS topologies want tightly coupled windings with tiny leakage inductances to avoid spikes, which is where sandwich construction is typically critical.
You're doing great work here and I applaud your contributions to improving the internet's signal-to-noise ratio. Thanks!
July 5, 2016 at 5:06 PM
Anonymous said...
Thanks for a brilliant article! Found it while looking for a reason for the mains ripple buzz felt on my new-to-me iPad 4 case while charging. Plugged the Lightning lead into different usb chargers - no buzz. Opened the charger and your photo told me it's the genuine Apple charger. At some point it's suffered moisture ingress to the pcb at the exact point where the 240V wires are soldered - live and neutral separated by only 4mm. Genius. Never ever had ripple through a usb lead before - ubiquitous with Apple products apparently. Still, if Apple say it's normal...
Ken... DAMN good post and thanks for the excellent meaty engineering you provided. I just linked my Facebook friends to your post. First the eastern markets give us tainted food, then lead in toys and now this. I understand people want to make money with their products but these guys have crossed the line into social irresponsibility.
March 16, 2017 at 7:29 AM
Anonymous said...
How did you take apart the two halves? I have an issue with mine and would like to open it.
Anonymous: to take the charger apart, I use a 3/4" wood chisel and hammer all around the seam to break the bond between the two halves. It sounds strange, but it works.
May 26, 2017 at 9:06 AM
Anonymous said...
Hi Ken, I am using an original charger for my MacBook Air. Some times the charger "shuts off". The led on the connector does not light up at all. However, after a few minutes, I am able to use it. Could it be because of spike in voltage beyond 250V?
I just wanted to comment on the 4 pin IC used in the fake charger. ON Semiconductor has a 3 pin that looks like a Transistor but it's actually a 4 pin Ic thats looks very similar to the one used in the fake charger. It's model number is NCP1075.
February 27, 2018 at 6:41 PM
Anonymous said...
Very well done! a few comments arising from other comments:
These absolutely are flyback converters. The thing commonly referred to as a flyback transformer is not used in the normal sense of a transformer where current flowing in the primary causes simultaneous current to flow in the secondary. It is actually an inductor with two windings. The input winding on the AC mains side is used to store energy in the inductor during part of the cycle. The sorted energy is delivered to the DC output side during another part of the cycle. To facilitate sufficient energy storage the core of the inductor will have a small air gap, normally in the centre leg but sometimes in all three legs (which are actually just 2 legs topologically). A flyback converter is instantly recognizable because there is only a single diode in the output circuit and no additional inductor. It is pretty much the only topology commercially used for low-power switchers. The name does derive from the circuit used in raster CRTs where the electron beam "flies back" across the screen. Because there is true transformer action among output windings, a decent job of regulating the main output voltage can be done with the winding that supplies the control circuit, saving the need to cross the isolation boundary with, typically, and optocoupler.
Kapton tape is about as useful for heat shielding as a t-shirt is for stopping bullets. It is moderately common as in inner layer in thermally conductive mounting pads for power semiconductors.
Triple insulated wire generally allows better "window area fill" in small transformers. Creepage and clearance requirements apply in the transformer too. You can loose a lot of the bobbing width to this with ordinary magnet wire which is considered to have no insulation for safety purposes. With some VDE standards, you'd lose 4 mm at each end, which is a heck of a problem when the whole bobbing might only be 15 mm long.
I believe the Y capacitors from line to the output ground or common, is what causes the tingling sensation one often gets from the metal case of a device being charged. It acts as a capacitive divider across the line input. So the case of the device is floating at half the mains voltage, relative to earth ground.
That, combined with body capacitance provides a fairly high impedance path for AC current to flow through your body. I generally feel it at my wrists that touch the edge of the case while typing on my laptop (2 prong adapter). This is mostly in countries with 240VAC mains, not so much in the states on 120VAC.
Any two prong device with normal RF bypassing from the lines to the output can do this. 3 prong adapters with a proper ground pin generally don't exhibit this, as long as the ground has a good connection.
October 14, 2019 at 7:39 PM
Anonymous said...
Hi, does anyone know which zener diode is on the ipad charger?
July 9, 2020 at 4:35 AM
J said...
The I Phone charger is made @Foxconn and ARTESYN The cost is USD1.5!!!
An anonymous commenter said: " I've changed 7 chargers in the last 7 months ... ... why doesn't anyone comment on the real issue - why do we need to replace an Iphone/ Ipad charger so frequently in the first place?"
OK, I'll comment.
I've seen A LOT of similar comments and in EVERY single case I've looked into either the charger WAS NOT an authentic Apple charger, or (most commonly) the cord connecting the charger to the device failed, not the charger! Most non-technical users refer to the cord as "the charger" and unfortunately, genuine Apple cords tend to fail right near the connector. Someone disconnecting the charging cord from the device by pulling on the cord instead of by grasping the plug could easily go thru 7 cords.
September 7, 2020 at 4:30 PM
Anonymous said...
Excellent work my friend. I thought I had bad grounds but it’s looking like a shit charger is doing it thank you kindly for this knowledge cheers
"iPad charger teardown: inside Apple's charger and a risky phony"
81 Comments -
Awesome post!
I my self have been planning to get one of those Apple chargers!
I have a Motorola Smartphone, And the charger that was came in the box works very well at 230V AC(I got the phone in India) and when i charge it on 110V(Here in the US) the touchscreen acts all funky! I even got an original US Motorola charger they sold at the Verizon Store and that charger has the same problem too..... Motorola needs to invest some more design resources in their charger design!
May 10, 2014 at 11:27 PM
Nice write up. But can I just point out that the secondary winding in the Chinese knock off is not bare un-insulated copper, rather enamelled copper - standard practice for any kind of electromagnetic type component be it transformer, inductor, motor etc.if it were plain copper the windings would all short out and the transformer would fail to work at all.
May 11, 2014 at 2:41 AM
I strongly feel that Ken knows that the secondary in the knock-off is insulated with enamel. I think he was trying to point out the insubstantial insulation rather than complete lack. Perhaps he will change the wording to satisfy the pedants.
May 11, 2014 at 5:57 AM
He keeps talking bout the so called 'flyback' transformer', yet both circuit examples use standard high frequency transformers - not flyback types.
The high frequency transformers used here create square waves and the frequency and pulse width are controlled by the IC to maintain the output of the high frequency transformer at the correct level of high frequency AC that produces the correct rectified voltage at the output. The Apple unit has the extra parts for superior control.
A flyback transformer is to make a ramped sawtooth wave for electron beam control in raster scan television, where the beam passes across the screen and is intensity modulated(made brighter and dimmer) to wtite the image line by line. At the end of each scan, the pulse from the flyback transformer makes the beam 'fly back' to the start of the next line.
http://en.wikipedia.org/wiki/Flyback_transformer
May 11, 2014 at 6:00 AM
I wish you had a similar overview on apple batteries!
May 11, 2014 at 7:34 AM
Very interesting post, thanks for sharing
May 11, 2014 at 11:44 AM
aurizon: The circuits do use flyback transformers. Please read the first paragraph of the Wikipedia article you referenced. Flyback transformers are used in old TVs and are also used in low-power switching power supplies. What you describe is a forward converter, which is a different power supply topology. There's a nice diagram here of different topologies. Also see footnote 2 of my article for more information.
mangodan: Yes, there's enamel of course. I'll clarify the text.
May 11, 2014 at 11:59 AM
Ken that was a fantastic post!
I want to thank you for an inspiring late evening read inspiring me to wish to do as well in what I do.
-- john Sheppard
May 11, 2014 at 8:06 PM
I want to add that I made the mistake of buying one of the fake chargers before. The ones that I've gotten had a wierd grounding issue where the touch screen responded oddly to all my input and If I picked up a device of. Mine, it shocked me. It was a 5 pack and it did that with every charger. Never again.
May 12, 2014 at 6:51 AM
The knockoff probably generates a lot of very broad-band RF interference as well.
May 12, 2014 at 11:42 AM
In discussing the ground pin, you mention that since the plug is two-prong, it does nothing. While this is true, these power bricks from Apple can also use the lengthy cable attachment instead of the direct plug. This cable does, in fact, connect that pin back to third pin ground. I always thought this was a clever design on Apple's part.
May 12, 2014 at 11:46 AM
How about doing a comparison with an MFi-certified charger, like from Monoprice?
May 12, 2014 at 2:23 PM
Incredible price! Any plans for teardown on lightning cables? I'm sure the Apple ones are safer, but $19?!
May 12, 2014 at 4:13 PM
How much do you value your iPad? After spending several hundred dollars on the iPad, which is a quality instrument, you're going to skimp on the charger? Penny wise, pound foolish. I say give the devil his due.
May 12, 2014 at 7:54 PM
This is particularly relevant when officials suspect this http://www.bbc.co.uk/news/uk-england-south-yorkshire-27371854
...was caused by a faulty charger.
Good post.
May 13, 2014 at 4:49 AM
I have a question about the weight of the two chargers.
Since the real iPad charger has more components and especially larger transformer, did you find any weight difference between the two chargers? Is this a reliable way to tell the difference of the real and fake charger?
May 13, 2014 at 5:16 AM
My wife bought a cheap charger 2 years ago for her iPad. After a short period it starting making a hissing noise and smelled of ozone. We threw it out and she bought an Apple charger instead. After reading this now I understand what it was doing and feel lucky we did not have a fire!
May 13, 2014 at 5:43 AM
Another option is to use a high quality but cheaper USB charger from Samsung or HTC which is what I have been doing for the last 2 years.
May 13, 2014 at 5:44 AM
so you're sayin the 5 chargers I just bought from china for $20 aren't good?????? .. kinda figured :-0
May 13, 2014 at 6:39 AM
This comment has been removed by the author.
May 13, 2014 at 7:08 AM
Very interesting post. I'd like to see the difference between Apple's 10W and the newer 12W iPad chargers.
May 13, 2014 at 7:27 AM
Can we get corrected photo links to the large photos? It's hard to see details in the article photos.
May 13, 2014 at 8:28 AM
Nice Review Ken
Clearly no NRTL or Internationally Recognized Lab actually reviewed the construction. Unfortunately some reported Counterfeit Apple Charger already cost a poor woman her life in China. http://www.scmp.com/news/china/article/1283818/woman-electrocuted-while-answering-iphone-may-have-been-using-fake?page=all
Hopefully your review can prevent further tragedies.
May 13, 2014 at 9:04 AM
Hi excellent in depth reviews and thoughts on iPhone iPad and a few other chargers . Feels good to reach such technical and actual engineering stuff on the internet.
I am from India and had an iPhone 4 in the past . Indian iPhones come with a rather different iPhone charger. Not the cube one. These chargers worked fine on iPhone 4 and 4S and since it's very hot in I they worked good in these conditions . But with the iPhone 5 I experienced the issue with touchscreen interference. I had 3 iPhone 5 and had the issue with all 3 so it has to be the charger. Same thing happened with a friend of mine so it's not just my charger. Now I'm currently using te cube iPhone charger which my sister got cause her iPhone was purchased in the US . The issue doesn't happen with iPad charger cause it's no different than the one sold in the US but the Indian iPhone charger seems to be not the same as the one in US in terms of power quality. If it's possible for you to get your hands on the Indian iPhone charger please take a look at it . It really is interesting as it only happens when the iPhone draws a lot of current initially for fast charging . And it's scary !
May 13, 2014 at 12:39 PM
Ken Shirriff needs to review his blog on the ipod charger against his reference:
Either the full-wave rectifier l,when the input voltage is 100Vac or 240Vac is 170Vdc to 340 Vdc or 145Vdc to 335Vdc.
Ken writes "You might wonder why the DC voltage inside the power supply is so much higher than the line voltage. The DC voltage is approximately sqrt(2) times the AC voltage, since the diode charges the capacitor to the peak of the AC signal. Thus, the input of 100 to 240 volts AC is converted to a DC voltage of 145 to 345 volts internally "
May 13, 2014 at 1:29 PM
Ken Shirriff needs to review his blog on the ipod charger against his reference:
Either the full-wave rectifier l,when the input voltage is 100Vac or 240Vac is 170Vdc to 340 Vdc or 145Vdc to 335Vdc.
Ken writes "You might wonder why the DC voltage inside the power supply is so much higher than the line voltage. The DC voltage is approximately sqrt(2) times the AC voltage, since the diode charges the capacitor to the peak of the AC signal. Thus, the input of 100 to 240 volts AC is converted to a DC voltage of 145 to 345 volts internally "
May 13, 2014 at 1:29 PM
I would love to see a comparison between the EU and US iPhone charger. The EU charger is (from what I understand) a bit smaller. The iPad charger seems to be he same, and that is logical as the plug can be exchanged, but the iPhone charger looks like a standard EU-plug, just a bit longer.
May 13, 2014 at 2:29 PM
Please don't use the term High Voltage when referring to low voltage appliances. I saw that you mention this in foot notes but 600V AC is high voltage not 110-240 line voltage. The knock off iPad charger is not going to Arc Flash.
May 13, 2014 at 6:25 PM
Banana... for scale? You're not a member on a certain image-sharing site, are you?
Hope you can teardown an Anker charger next!
May 13, 2014 at 10:13 PM
It's also notable that Apple has certified the US adapters for 400 Hz AC, undoubtedly due to the interest in airlines using iPads in the cockpit.
http://support.apple.com/kb/HT6128?viewlocale=en_US&locale=en_US
May 13, 2014 at 10:55 PM
AMAIZING POST!
I too was a culprit of a counterfeit charger, I bought one which looked exactly like the apple one when in hospital, when I got home it got mixed up with the official ones and when plugged in one day,BOOM! It exploded off the wall game me and shock and sent sparks everywhere pand my little boy was 3ft away...
I will never buy a counterfeit charger or even use one again.
May 14, 2014 at 12:45 AM
Thanks for writing up this detailed post. I was thinking of getting one of these cheap knockoffs as a spare charger, now that plan's out of the window.
I always wondered why some of the cheaper chargers for android phones made the phone act funny, especially funky behavior on the touch-screens side, now I have some idea, thanks to you.
May 14, 2014 at 8:35 AM
Thank you, Ken!
Impressive detail and thorough treatment throughout makes this a must-read, must-bookmark reference--one I will be sure keep handy to send around to too-cost-conscious owners of iThings I know intent on replacing their chargers.
"You get what you pay for" seems to be the overall message--but in this case you've given the iAudience a free lunch and much food for thought. Much appreciated.
May 14, 2014 at 11:22 AM
This comment has been removed by the author.
May 14, 2014 at 9:56 PM
Excellent article.
I think we could say a little more about those blue "Y" capacitors.
They come in two varieties: "Y1" and "Y2", and perhaps counter-intuitively, a Y1 cap has twice the voltage rating of a Y2. Basically, Y2's are designed for US 110V mains, while Y1s are meant for European 220-240V mains. Or, you can put two Y2's in series to give the equivalent of one Y1
In most cases, they're all that sits the user and the AC power line, so they obviously are a very special component, and have to be made as reliable as technologically possible.
"250V Y1" actually means: "This component can safely be wired between 250V AC mains and exposed metal parts accessible to the user, and will safely withstand voltage surges up to 5,000V without damage or hazard to the user."
Y2 capacitors are rated at half these voltages and are intended for 110V mains.
Voltage surges are far from uncommon on normal AC power lines. They can be caused by switching off of heavy inductive loads, lightning hitting power lines, trees falling on power poles holding both domestic and high voltage distribution cables.
In my experience, Y1 capacitors can withstand up to 10,000 Volts DC at least for short periods. (They could go higher, but past that point, sparks tend to start jumping across the leads!)
But now we come to the really nasty bit. It's not at all uncommon for unscrupulous (or just plain ignorant) power supply manufacturers to substitute ordinary DC-rated ceramic capacitors in place of the pricier Y-rated types. Most commonly you'll see a tiny brown "1,000 V DC" ceramic capacitor instead of the much thicker blue Y-rated type. (I have also seen the same types, painted blue!)
A 1,000 V DC rating has a completely different meaning from "250V Y1", and the component will typically go short-circuit if you apply more than about 900V AC to it, a far from uncommon ocurrence on normal power mains.
If the voltage spike manages to kill the AC adaptor as well, that's not so bad. Not ideal, but at least the user will stop using the device. But the worst problem is that it is entirely possible for the capacitor to go short-circuit and the power supply to go on working, except that the DC output pin (or USB shell) is now live!
It's also entirely possible for the adaptor to go for years like that, until someone touches the exposed metalwork while standing on damp ground or leaning on a grounded metal sink...
Ironically, I've seen many examples of perfectly-good designs, with the correct creepage and clearance and so on, and then they go and screw it up by fitting a crap cap!
May 14, 2014 at 10:02 PM
That "redish insulating film" is not there for electrical insulating.
It called "Kapton tape" and it is for heat-shielding.
May 14, 2014 at 10:56 PM
How fast it charges and does it catch on fire, are pretty much the only factors that matter. I suppose if there's a potential for long term damage to the device, but on the whole, even iPads are quite nearly throw away items now. We had the same discussions years ago with power supply/power conditioners for servers and at the end of the day, spending $3500 for a state of the art power conditioner to provision a bunch of commodity servers makes no sense. Especially given that power supplies and conditioners themselves actually have a finite service life.
May 15, 2014 at 6:27 AM
Any feel for if or how power consumption and output is handled without a device connected. Including when a lightning cable is plugged in to the USB port in the charger but not pluged into a device.
Thanks
Dan
May 15, 2014 at 10:31 AM
IANAEE. I am not an electrical engineer, so pardon the stupidity of this question.
This post is very informative and timely for my needs. My question is related, I think. I don't want to use a cheap transformer/charger, but I do want to use existing wiring and a good-quality transformer to power iPad Minis and instead of the chargers (adapters) that come with the iPads.
I want to install 9 or 10 iPad Minis on my walls (for A/V control). I can't re-wire to provide power. I would like to use the existing Crestron (Cresnet) wiring to provide low-voltage power directly to the iPad Minis, instead of using 120V and chargers/adapters since there is no near-by power source.
The Cresnet wiring seems capable of handling the required load. From the Crestron site: "Cresnet is a simple, yet flexible 4-wire network that provides bidirectional communication and 24V power". One pair of the stranded bare copper wires is 22AWG x2 (which Crestron uses for data), and the other pair is 18 AWG x2 (which Crestron uses to power its soon-to-be-replaced wall panels). Is my assumption correct that the in-place wiring can handle the requirements of the iPad Minis?
I want to use a high-quality transformer, located at the head-end (where my existing A/V equipment is) to provide the 10w (or is it 12w?) power that the iPad Minis need. I'd use a transformer with these specs:
DC VOLTAGE 15V
RATED CURRENT 10A
CURRENT RANGE 0 ~ 10A
RATED POWER 150W
VOLTAGE ADJ. RANGE 14.3 ~ 16.5V
(See this transformer: http://www.jameco.com/Jameco/Products/ProdDS/173412.pdf)
Am I crazy, crazy stupid, just stupid, or on the right track?
Thanks in advance for your help!
May 15, 2014 at 5:01 PM
why dont they pot BOTH Chargers with Epoxy?
May 22, 2014 at 5:38 AM
I have had a cheap Amazon knock off for over two years. I'm haooy with it.
May 22, 2014 at 8:00 AM
This comment has been removed by the author.
June 1, 2014 at 9:28 AM
What would be the leakage current from two 220pF Y capacitors in the iPad charger based on the voltage and frequency? When I touch the edge of the lightning connector to the ground screw on the UPS in the dark room I sometimes see tiny blue spark due to momentary spike as the capacitor equalizes to AC voltage. Can this spike cause a static like shock each time the device is touched while body is grounded.
June 5, 2014 at 10:31 PM
I have an iPhone charger came with my iPhone. After reading your post, I became suspicious that it could be a counterfeit one because it had a plastic ground pin and the text on its body became unreadable after several years of usage. I cracked it open and found it's genuine! This charger came with my iPhone 4 and had an iPad charger's form factor. Surprisingly I didn't find the control IC in it. It had a second small board (about 7mm x 15mm) attached vertically to the main one. It has 3 traces joined to the main board. One of the trace connected to the gate pin of the switching MOSFET on the main board. I thought this board must function as the control IC.
June 27, 2014 at 12:51 AM
I sent your article to a newspaper, so they could accurately report on the latest death. They seem to have used it.
Thanks again for putting the effort in.
June 27, 2014 at 5:40 PM
A fantastic article, found you from The Register, very interesting read and very educating for all, surprised me just how complex a changer actually can be. Good stuff :) Simon B
July 1, 2014 at 1:22 AM
Interesting and thorough teardown. I had a look into my own counterfeit iPad charger that recently burnt, and while mine appears to follow better safety guidelines (including crepe distance and insulating fin), it wasn't up to the job eventually.
September 20, 2014 at 2:32 PM
Great post and very informative.
I have a question. How would the charger handle a high frequency input or say 400Hz at 110V? Is the circuit capable of safe operation over time or would it exceed the design of any components.
Thanks
October 3, 2014 at 1:59 AM
Anonymous: I'd expect the charger to work at 400Hz. The first step in the charger is an AC to DC diode bridge, which shouldn't be affected by the frequency. After that point, the circuit runs off DC, and the frequency won't matter. But when you're running out of spec there aren't any guarantees, so don't blame me if something goes wrong.
For more on running power supplies at 400Hz, see this article.
October 3, 2014 at 11:58 AM
Since it has a transformer does that mean it still consumes power even if you just leave it plugged in a wall without an ipad?
How about the macbook charger? i'm curious as to how they made it smaller than usuall brick type chargers :)
November 11, 2014 at 5:38 AM
Great article! Can I have your permission for translating the article into Turkish?
November 12, 2014 at 4:11 PM
Anonymous: yes, the charger consumes a small amount of power when plugged in without an iPad. The Macbook charger uses a more complex switching power supply circuit (with PFC in some models). They make it small basically by cramming stuff in there through careful design.
Firat: sure, you can translate it into Turkish. Thanks for asking. I'd be interested in seeing the Turkish article when you're done, so send me the link.
November 12, 2014 at 7:56 PM
Great info. I've changed 7 chargers in the last 7 months; so I'll take note..
But why doesn't anyone comment on the real issue - why do we need to replace an Iphone/ Ipad charger so frequently in the first place? Someone said penny wise and pound foolish - well, if your buying such a quality product which is the premium in its segment, why should the charger be of such low quality in any case? Why haven't we heard of Samsung and Blackberry users needing to change their chargers so often?
Could it be that Apple is just too greedy? They design poor chargers so that we will need to buy again? And they are clever enough to just leave a bit of gap in their clever engineering so that no one notices..?
November 18, 2014 at 10:30 PM
Have you measured leakage current between the aluminum case and earth ground while charging? Anyone report any tingling in the 120V or 240V regions?
November 19, 2014 at 6:02 PM
Hahaha, I always laugh when people who get the newest most expensive iphone buy a cheap 1 dollar charger. if you got so much money that you spend 800-1000 dollars on a phone then why not get a proper charger? Apperently the people are rather poor. Ridiculous.
December 7, 2014 at 8:31 AM
Those actually look pretty safe compared to the ones I just got off ebay a few weeks ago.
This item: ebay
Looks like this from the inside: photos
No spark gap to be found... at all.
December 25, 2014 at 5:31 AM
"Anonymous" above complained (understandably) about having to replace AC adapters 7 times. I'd be upset, too.
That said, there's just no way that's normal. Something really bad is happening with your power, frying those adapters.
I still have every iPod/iPhone AC adapter I've ever had, and none has ever failed. (That's something like 7 or 8 in all.) Nor have I ever heard of them failing from friends or acquaintances. This just isn't some widespread problem.
Whatever the cause of the failures, it's not the build quality -- assuming you're talking about genuine Apple adapters, not counterfeit ones.
February 16, 2015 at 4:11 PM
Apple doesn't seem to care about the 80% derating rule. In products with universal input (for both US and Europe) the filtering capacitor after the bridge should have 450V voltage rating. This is the norm everybody follows, except cheap Chinese manufacturers. Apple too uses 400V.
February 19, 2015 at 3:22 PM
Thanks for your article, very informative. I really like that you not only posted an opinion, but real facts. I have bought non-Apple cheap chargers in the past and when I opened one I realized it was different than the Apple original, I saw some of the differences you pointed out. But with your article I learned mode about that differences (specially the safety related ones). Thanks for sharing.
Regards, MV.
February 20, 2015 at 3:51 PM
Thanks for great and informative article!
I wonder if supplying a power to iPhone from any Mac has any difference comparing to wall chargers? All Macs since 2007 can add 500 mA to standard 500mA USB output for iPhone (and additional 1600mA for iPad!).
Thanks!
February 27, 2015 at 2:53 AM
I just want to know, of the knock-off brands, which are considered the better ones. Anyone?
April 3, 2015 at 2:38 PM
Thanks for the in-depth article. I was just about to crack open my Ipad 3 10W charger to check out the innards. Now I don't have to.
While these supplies are called Flyback ,Aurizon's comment about the old CRT scan circuits being the origin of the flyback designation. In those supplies the magnetic storage was primarily in the deflection yolk and the flyback pulse routed through the High Voltage transformer. These supplies have more in common with older automobile ignition systems than the CRT supplies.
to answer two queries above. The leakage current through the Apple supply is about 8 microamps at 60 hz 120 VAC. while at 400 hz while the noise factor and filtering will be markedly better, the AC leakagage through the Y caps will increase to nearly 46 microamps.
May 17, 2015 at 6:38 PM
Thanks,
I purchased two of these counterfeit chargers for my MacBook from eBay which is notorious for counterfeit electronic peripherals. At the time I didn't think it was counterfeit until I went through the first one in less than 3 months. It started making this "clicking" noise. So I figured maybe I burned it out or shorted it out by mistake. The second one, the cord didn't feel genius like the original. Luckily I kept the original charger that came with the MacBook and didn't throw it away. Make a long story short, the best way I can tell if a charger is real or not, is compare it with the original. If the other charger weighs less, then it more than likely is fake.
September 9, 2015 at 4:01 PM
I REALLY love this series of breakdowns on the Apple chargers, etc. They not only provide a meaningful analysis of what a good component is - but make it clearer from a grand perspective - why and how these now-pedestrian, yet insanely complex devices are built the way they are. Cheers!
October 1, 2015 at 5:48 AM
very interesting article , never thought i would get to see the internal part of charger..thanks for sharing
October 14, 2015 at 4:26 AM
Hi Ken!
There are a few points I'd like to mention.
1. Your use of "high voltage" versus "low voltage" isn't the right term in dealing with creepage or clearance. While there are distances between conductors the rules based solely on voltage are straightforward. I believe "primary" and "secondary" are better terms because that will indicate the requirement for isolation from the AC line.
2. The enamel coating on the cheap transformer windings needs to only stand off the turn-to-turn voltage, except at the crossover. This isn't much voltage. And a single piece of tape can easily handle the crossover. Using triple insulation is a tool, not a requirement, and there are valid reasons for using it and valid reasons for avoiding it in any specific design. And each designer may have their own preferences. While it's unquestionable that triple-insulated wire will have a higher voltage breakdown, that does not mean it's less safe.
3. Some transformers may not want to have tightly-coupled windings. In fact, flyback converters must have some substantial uncoupling to provide the primary inductance that stores energy. So using a sandwich construction may be a good design, or it may not be. It just depends on how the circuit is designed. In fact, avoiding a sandwich and intentionally separating the windings to increase inductance can be of great benefit if the flyback is designed to take advantage of that construction technique. While it does add more money, the cost is slight and doesn't reflect on the build quality or design. Most SMPS topologies want tightly coupled windings with tiny leakage inductances to avoid spikes, which is where sandwich construction is typically critical.
You're doing great work here and I applaud your contributions to improving the internet's signal-to-noise ratio. Thanks!
July 5, 2016 at 5:06 PM
Thanks for a brilliant article! Found it while looking for a reason for the mains ripple buzz felt on my new-to-me iPad 4 case while charging.
Plugged the Lightning lead into different usb chargers - no buzz.
Opened the charger and your photo told me it's the genuine Apple charger.
At some point it's suffered moisture ingress to the pcb at the exact point where the 240V wires are soldered - live and neutral separated by only 4mm.
Genius.
Never ever had ripple through a usb lead before - ubiquitous with Apple products apparently.
Still, if Apple say it's normal...
September 18, 2016 at 4:03 PM
Ken... DAMN good post and thanks for the excellent meaty engineering you provided. I just linked my Facebook friends to your post. First the eastern markets give us tainted food, then lead in toys and now this. I understand people want to make money with their products but these guys have crossed the line into social irresponsibility.
March 16, 2017 at 7:29 AM
How did you take apart the two halves? I have an issue with mine and would like to open it.
May 25, 2017 at 3:32 PM
Anonymous: to take the charger apart, I use a 3/4" wood chisel and hammer all around the seam to break the bond between the two halves. It sounds strange, but it works.
May 26, 2017 at 9:06 AM
Hi Ken, I am using an original charger for my MacBook Air. Some times the charger "shuts off". The led on the connector does not light up at all. However, after a few minutes, I am able to use it. Could it be because of spike in voltage beyond 250V?
November 11, 2017 at 7:02 AM
I just wanted to comment on the 4 pin IC used in the fake charger. ON Semiconductor has a 3 pin that looks like a Transistor but it's actually a 4 pin Ic thats looks very similar to the one used in the fake charger. It's model number is NCP1075.
February 27, 2018 at 6:41 PM
Very well done! a few comments arising from other comments:
These absolutely are flyback converters. The thing commonly referred to as a flyback transformer is not used in the normal sense of a transformer where current flowing in the primary causes simultaneous current to flow in the secondary. It is actually an inductor with two windings. The input winding on the AC mains side is used to store energy in the inductor during part of the cycle. The sorted energy is delivered to the DC output side during another part of the cycle. To facilitate sufficient energy storage the core of the inductor will have a small air gap, normally in the centre leg but sometimes in all three legs (which are actually just 2 legs topologically). A flyback converter is instantly recognizable because there is only a single diode in the output circuit and no additional inductor. It is pretty much the only topology commercially used for low-power switchers. The name does derive from the circuit used in raster CRTs where the electron beam "flies back" across the screen. Because there is true transformer action among output windings, a decent job of regulating the main output voltage can be done with the winding that supplies the control circuit, saving the need to cross the isolation boundary with, typically, and optocoupler.
Kapton tape is about as useful for heat shielding as a t-shirt is for stopping bullets. It is moderately common as in inner layer in thermally conductive mounting pads for power semiconductors.
Triple insulated wire generally allows better "window area fill" in small transformers. Creepage and clearance requirements apply in the transformer too. You can loose a lot of the bobbing width to this with ordinary magnet wire which is considered to have no insulation for safety purposes. With some VDE standards, you'd lose 4 mm at each end, which is a heck of a problem when the whole bobbing might only be 15 mm long.
December 13, 2018 at 3:04 PM
Dear Ken,
maybe take a look to my charger. If I connect it to the iPad, the keyboard beginns to waves
[URL=https://www.bilder-upload.eu/bild-0f6f38-1552393801.jpg.html][IMG]https://www.bilder-upload.eu/thumb/0f6f38-1552393801.jpg[/IMG][/URL]
Best regards, Andreas
March 12, 2019 at 5:33 AM
Dear Ken,
please takle a look to my charger. If I connect it to my iPad, the keyboard beginns to weaves:
Is it original or a fake?
https://www.bilder-upload.eu/bild-779404-1552394072.jpg.html
best regard, andreas
March 12, 2019 at 5:37 AM
I know clearly about ipad charger, for example, it's structure.
but what kinds of electronic components does the ipad charger use?
May 28, 2019 at 3:56 AM
I believe the Y capacitors from line to the output ground or common, is what causes the tingling sensation one often gets from the metal case of a device being charged. It acts as a capacitive divider across the line input. So the case of the device is floating at half the mains voltage, relative to earth ground.
That, combined with body capacitance provides a fairly high impedance path for AC current to flow through your body. I generally feel it at my wrists that touch the edge of the case while typing on my laptop (2 prong adapter). This is mostly in countries with 240VAC mains, not so much in the states on 120VAC.
Any two prong device with normal RF bypassing from the lines to the output can do this. 3 prong adapters with a proper ground pin generally don't exhibit this, as long as the ground has a good connection.
October 14, 2019 at 7:39 PM
Hi, does anyone know which zener diode is on the ipad charger?
July 9, 2020 at 4:35 AM
The I Phone charger is made @Foxconn and ARTESYN
The cost is USD1.5!!!
July 29, 2020 at 1:09 AM
An anonymous commenter said: " I've changed 7 chargers in the last 7 months ... ... why doesn't anyone comment on the real issue - why do we need to replace an Iphone/ Ipad charger so frequently in the first place?"
OK, I'll comment.
I've seen A LOT of similar comments and in EVERY single case I've looked into either the charger WAS NOT an authentic Apple charger, or (most commonly) the cord connecting the charger to the device failed, not the charger! Most non-technical users refer to the cord as "the charger" and unfortunately, genuine Apple cords tend to fail right near the connector. Someone disconnecting the charging cord from the device by pulling on the cord instead of by grasping the plug could easily go thru 7 cords.
September 7, 2020 at 4:30 PM
Excellent work my friend. I thought I had bad grounds but it’s looking like a shit charger is doing it thank you kindly for this knowledge cheers
March 8, 2021 at 8:43 AM