Did you ever wonder why Apple’s $29 USB Power Adapter for the iPhone costs so much more compared to, say, Samsung’s cube charger that goes for about $6-$10 (and looks all too familiar).

Alright, everything Apple is more expensive because the company makes integrated products that “just work”, right?

But as tough as it is to argue against Apple pricing its shiny gadgets accordingly, it’s far too easy to criticize Apple accessories that many people think cost more simply because of the official branding.

In the case of the original Apple USB Power Adapter, there is no merit to this argument for there’s more to your iPhone charger than meets the eye…

Blogger Ken Shirriff took it upon himself to tear down a $29 Apple charger in order to figure out just how complex the tiny thing is. In a nutshell, the little device “takes AC input (anything between 100 and 240 volts) and produce 5 watts of smooth 5 volt power, but the circuit to do this is surprisingly complex and innovative”.

The switching power supply turns the input power on and off around 70,000 times times a second in order to get the exact output voltage required. There are two tiny printed circuit boards inside, packed with surface mounted components on both sides.

The primary board takes care of high voltage while the secondary board handles the low voltage from the transformer and feeds it to the circuitry. A second feedback circuit also shuts down the charger for protection in case of overheating or if the output voltage is too high.

This is where things get interesting, Shirriff writes:

The USB output also has specific resistances connected to the data pins to indicate to the iPhone how much current the charger can supply, through a proprietary Apple protocol. An iPhone displays the message “Charging is not supported with this accessory” if the charger has the wrong resistances here.

The charger also packs in a Flextronics-patented resonant clamp circuit that absorbs voltage spikes on the transformer.

The device has a bunch of components ordinarily not found on other chargers. These work together toward reducing EMI interference with the iPhone’s touchscreen while enhancing the iTunes listening experience.

The transformer includes a shield winding to absorb EMI. The output circuit uses three capacitors including two relatively expensive tantalum ones and an inductor for filtering, when many supplies just use one capacitor. The Y capacitor is usually omitted from other designs. The resonant clamp circuit is highly innovative.

As for the controller circuitry, it runs on DC power provided by an auxiliary power circuit consisting of a separate auxiliary winding on the transformer, a diode and filter capacitors.

But how does the controller circuitry gets DC power before the main transformer starts generating power?

The solution is the high-voltage DC is dropped to a low level through startup power resistors to provide the initial power to the IC until the transformer starts up. The auxiliary winding is also used by the IC to sense transformer demagnitization, which indicates when to turn on the switching transistor.

This is what the secondary circuit board from the iPhone charger looks like.

Optocuplers are in the upper left and feedback circuitry is in the lower left.

Filter inductor, capacitor and diode provide output.

And perhaps unsurprisingly, all these components are crammed into impossibly tiny space, as you’d expect from Apple.

Looking at these pictures, it’s easy to lose track of how very small these components are, and how the charger crams all this complexity into one inch. The following slightly magnified picture shows a quarter, a grain of rice, and a mustard seed to give a size comparison.

Most of the components are surface-mount devices which are soldered directly to the printed circuit board. The smallest components, such as the resistor pointed out in the picture, are known as “0402” size since they are .04 inches by .02 inches. The larger resistors to the left of the mustard seed handle more power and are known as “0805” size since they are .08 x .05 inches.

Even with cutting-edge tech that goes into this thing, Apple’s charger is “almost all profit”, Shirriff wrote:

I was surprised to realize how enormous Apple’s profit margins must be on these chargers. These chargers sell for about $30 (if not counterfeit), but that must be almost all profit.

He estimated that the Apple charger has “about a dollar’s worth of additional components” inside compared to Samsung’s charger, “but it sells for $20 more”.

Summing up:

Apple’s power adapter is clearly a high-quality power supply designed to produce carefully filtered power. Apple has obviously gone to extra effort to reduce EMI interference, probably to keep the charger from interfering with the touchscreen. When I opened the charger up, I expected to find a standard design, but I’ve compared the charger to the Samsung charger and several other high-quality industry designs, and Apple goes beyond these designs in several ways…

Apple’s design provides extra safety in a few ways… the super-strong AC prongs, and the complex over-temperature / over-voltage shutdown circuit. Apple’s isolation distance between primary and secondary appears to go beyond the regulations…

Apple’s iPhone charger crams a lot of technology into a small space. Apple went to extra effort to provide higher quality and safety than other name-brand chargers, but this quality comes at a high cost.

I think Shirriff’s findings are surprising, at least to me.

I know about Apple’s penchant for going the extra mile to create awesome gadgets, it’s just I wasn’t expecting so much care would go into designing a charger.

What’s your take?

  • Jeff, i’d like you, but. Sometime. You are so arse(…….) don’t get me wrong

    • ?

    • It’s posted by Christian

    • If you see an arse article, you should automatically assume that it is Christian. He is the worst writer here.

      • Anonymous


      • i concur

      • his writing is not that bad its good to me. just appreciate it

      • The big problem here. Biased. Disrespecting other companies. Since this became a news website, the worst thing I cannot stand is someone insulting someone in their article.

    • Lol not even his article and you diss him… Why don’t you just follow him on twitter and tell him there… You clearly need to read the author of the article before commenting lol

      • Kiel Wallace

        because he disables commenting on any article to do with samsung since he went gung ho on the wrong guy with the RIM stunt.

  • Laszlo Gaspar

    Steve jobs set this kind of standard way back when apple first started. Jobs once did not like the way the components where positioned on the macintosh mother board so he had the board made again. It’s nice to see his standard is still around.

    • Anonymous

      Jony Ive’s (and Apple’s) mantra is that good design doesn’t stop on the outside.

    • James Otis

      Steve Jobs set the standard which was “Charge more than anyone else because Apple fans believe higher cost equates with higher quality–and it really means a higher profit margin for Apple.” Don’t get me wrong. I have an Iphone and love it. But the “we’re better and smarter” attitude of the majority of Apple users both funny and irritating.

  • European Chargers look nothing like that.. have the UK one and the Portuguese on (way way slim) and i bet it’s different

  • Anonymous

    “Did you ever wonder why Apple’s $29 USB Power Adapter for the iPhone costs so much more compared to, say, Samsung’s cube charger”

    1) No, i’ve honestly never wondered.
    2) I don’t care either, it’s a charger ffs and no matter what fanboy spin you put on somehting you will never justify the price of it.

    • Anonymous


    • Anonymous

      Justify the price? It clearly stated it uses more expensive parts, and is just more work to put together then any other charger. I agree it’s a little too expensive, but after reading this i think the price should at least be $10 cheaper instead of $20 cheaper.

      Bottom line……..The more labor and expensive parts the more expensive the product. It makes perfect sense…

      You may not care but this article has inspired me to use nothing but Apple chargers to charge my iPhone…….Which sucks, for me, the customer…….but I paid a lot for my phone and want to get the absolute most out of it…I’m definitely not gonna give my phone mediocre care with cheap chargers because I’m mad about the price.I want it to lasts.

  • mordechai eliyahu

    jesus just buy one on amazon for $1.99 and on sale for .99 plus $15 shipping truth is i just want the jailbreak absinth 2.0 allready

    • Tom

      I don’t understand why people whine about jailbreaks in unrelated articles. It’s not like the articles being posted take time away from work on the jailbreak.

      • mordechai eliyahu

        true but everytime i c a new post i get my hopes up that then jb came out

      • Anonymous

        Then keep your jailbreak comments to yourself until there is an article about it.

  • Those chargers are straight up profit even if they are better. I love apple products but the accessories sold at “their” price is usually rediculous

  • Anonymous

    I don’t get this article, tear apart the Samsung charger it will look very similar. There are very few methods of converting AC to DC, they all do the same thing. The requirements of reducing interference are federal regulations, they all do it to meet the FCC.

    In fact, I think the only thing you’ve explained to me is that Apple is indeed only making a profit on us and doing nothing special in their $30 charger. In fact, they’re pulling a Dell and making their charger a proprietary system so you’re forced to buy the $30 charger.

    Maybe one day I’ll like an article you write Christian, one day. But right now, you’re just excited at a tear down of a common electrical device, and seem to be in wonder at its circuitry as if it’s some magical Appley goodness.

    • Anonymous

      “magical Appley goodness”!!

      Stop… I can’t take any more!!

    • Anonymous

      I agree that he comes off as a complete fanboy but the charger does do more than the cheap ones. Is that worth the $30 price? Hell no.

      • Anonymous

        Did you not read what I said? What more does it do? I already stated that the ElectroMagnetic Interference (EMI) is a specific federal regulation from the FCC that ALL charging devices meet. Ever notice the FCC logo on the back of your iPhone, it meets FCC regulations as well for wireless devices. There’s zero evidence of the “super Appley charger” blocking more EMI as a little 5W AC to DC converter doesn’t put out but a very small amount anyway. And no, it’s not what the guy says about “probably to keep the charger from interfering with the touchscreen” as that doesn’t make sense.

        Everything that was listed in this article is conjecture (“probably exceeds regulations”) as I’m sure he didn’t look up the specific regulation, get an expensive Fluke meter and measure per FCC guidelines or got it UL tested. This article was just complete bullshit as I’ve said.

      • Anonymous

        Why would Apple over engineer it? You’re assuming just as much as the guy who tore it down.

  • To me, working with electronics every day at work, this is very interesting. Almost no other, if any, manufacturer take their attention to detail to this level. Because honestly, no one opens these things.

    I thought this was an interesting article. Thanks for sharing, Jeff.

  • If they made the charger of gold, it does not mean they should charge more than the reasonable price. There are some pricing standards, which apple clearly does not follow.

    Recently I had to buy a new MacBook charger….it was for 90 bucks. For a damn charger 90. With a bit of extra cash i could buy a laptop for it. Luckily, I found some on eBay for 25.

    • Anonymous

      I totally agree.

    • Simply becuae apple decides to do something really good, it should not affect the price. The good or company should be chracterized by doing the best product with the competetive prices with other products on the market.

      • KewlDewd

        I’m sorry, but this is an incredibly ignorant statement. I understand it’s an opinion but it’s quite ridiculous. If a company decides to make a better quality product than the competition you think they should charge the same price as the competition even though they spent more on development and/or parts and/or labor? Or are you trying to say that Apple should make lower quality products only to be able to sell for the same price as the competition? Ridiculous either way.

      • I would like to see apple products at the competitive price. I don’t want to buy their laptop for 2200 and beside it there is 2 times stronger hp laptop for 1300.

        lets face it, the price apple is asking for is really high. And sometimes it does not make any sense for an average user to pay that price. As far as I know Apple is trying to sell the product to the average customer, who does not need the best hardware available.

        So you saying it does not make any sense, ok? I guess you would like to see apple increase the price, because their products are so great??

        I dont understand it. Or maybe you think the price is just right for their laptops.

      • Instead of focusing on my ignorant statement, focus on a deeper understanding. The prices fort apple laptops are incredibly hight. And please don’t try to justify the apple prices, because there is not a good excuse for this.

      • And apple does not always makes better quality products, my laptop already broke, my 2 iphones are already broken. And I am just waiting for them to get worse.

        Not to mention, the customer service is pretty horrible. Every thing they tell me must end with the word “PAY”. They could not fix or replace anything for free or with reasonable fee. Instead they told me to buy a new iphone from them for 200.

      • KewlDewd

        “And please don’t try to justify the apple prices, because there is not a good excuse for this.”

        LOL. I don’t have to justify their prices. They do it on their own. There is a perfectly good excuse for it. The BEST excuse for it. Listen closely…. They can charge that price because enough people are willing to buy at that price. It’s basic economics.

        “I guess you would like to see apple increase the price, because their products are so great??”

        You’re putting words in my mouth, and further showing how out of touch you are. Why would anyone want to pay more for something? Of course I’d like to pay less for Apple stuff.

        “And apple does not always makes better quality products, my laptop already broke, my 2 iphones are already broken. And I am just waiting for them to get worse.”

        True, they don’t always make better quality products. But they also don’t force you to buy their products. You’re confusing me. If you think they are way overcharging, why on earth did you buy a laptop and 2 iPhones. Not exactly a good argument for your intelligence.

        “Instead of focusing on my ignorant statement, focus on a deeper understanding.”

        Something you clearly have not done. I wouldn’t call wishing Apple didn’t charge so much for their products a “deeper understanding”.

        “As far as I know Apple is trying to sell the product to the average customer, who does not need the best hardware available.”

        I think that is the direction Apple is heading. In the past, Apple has only really been interested with people that want the best overall computing experience and who are willing to pay for it. Since the iPod and iPhone, they have started to aim for the average consumer, but I’d also argue that iPod/iPhone/iPad have been pretty competitively priced compared to comparable competing products.

        It really just boils down to the fact that Apple charges what they do because people are willing to pay it. If people stopped buying, they would have to cut prices (possibly lowering quality) or fail as a business.

      • Well, I remember apple always overcharged customers even in the ear of Microsoft. Apple was barely holding on, when Microsoft was doing whatever wanted to do. Yet, Microsoft did not overcharged as much as apple is now and back then.

        I can cleraly see you are not going to say I am right at any point, instead you try to pick an argument In each sentence where there is place for a debate.

        I bought apple products because I was really curious about all this fuss. And I got to say I was never excited about what they have to offer. At the same time I felt guilty of spemding this much money for the devices I could simialr for thr half of this price.

        And you are right!!! I insultend my intelligence by spending so much money on products which will be obsolete in 2 years. Or maybe apple imsults all of us.

        And you don’t really need to quote me I know what I say. No need to remind it.

        I think you are confusing yourself too. You are standing firm and defending apple. Yes They don’t force me to buy their devices. However, they are well aware that they can overcharged because they have prestige that they built for over 20 years.

        It is still not a good excuse for the high prices they have. So far you did not tell me anything new, except I got answer from you that apple can charge as much as they want becuase they are on top.

        Is this a good company?

    • Orlando

      I bought a Macbook Charger on eBay… Paid 35 dollars and i was super duper happy… But it only lasted a week… Burnt out… So i decided to invest 90 on an actual apple charger.. It is torn and wires are hanging and all, but it still works. I actually just bought a new one but im going to keep using the old until it doesnt work. Honestly, i’d choose Apple products any days and their prices are very reasonable.

      • Damian W

        I damaged already my two original Apple chargers. Just a week ago I got my 3rd one. All were in perfect condition and they probably had a short circuit at some point. There is no excuse for apple that 100 dollar cable stops working after a one year of moderate use. My 10 dollar charger for windows laptops lasts 5 years. Clearly apples chargers are not reliable. They look and feel great, give even an impression of sturdy looking, but they break in the most bizarre way. Once they break there is no way to fix them.

  • After reading the title and first sentence…I decided to not read the article. I like some apple products,but i can’t stand fanboyism. “All too familiar” lol

  • After reading the title and first sentence…I decided to not read the article. I like some apple products,but i can’t stand fanboyism. “All too familiar” lol

  • how about a smaller iPad charger?!?!! if they get it down to the same size as the current iPhone charger, i’d be impressed. i only use iPad chargers now.

    • Anonymous

      Because the iPad charger is a higher wattage and can push more amps to power the iPad quicker (also why the iPhone charges faster on an iPad charger). You cannot cram the 10W into the 5W iPhone charger footprint because of heat dissipation issues at this time with cheap components.

    • I take it your not in the UK.. It’s the same charger for bith

  • Siv

    Christian Zibreg, GO AWAY. No one likes you and your BS articles.

  • I found this pretty interesting I don’t understand why some of you find it stupid or BS….

    • Robert Goldberg

      I don’t understand why everyone is being so aggressive and mean to him either. If you don’t like it, just don’t read it.

  • Yeah, the cable is a work of art. Every cable I’ve had for my iPhone has split open. “Work of art” that is!

  • man you’re so brainwashed…….. i’ve got iphone, but i hate apple..they have great but overpriced devices…..if they could they would charge us the air…they think they invented the universe and that everything belongs to them!!!!fuck apple and fuck jobs “CHARGE EVERYTHING 10 TIME MORE THAN ITS WORTH” way of thinking…but S. J.-the inventor, R.I.P.!!!

    • Kok Hean

      The few steps of identifying a fanboy.

      Step one: Claiming to own a competitor’s device.
      Step two: “Hate” the competitor’s company.
      Step three: Make up exaggerated lies about the competitor’s company.

      Congratulations. You’re a fanboy.

      • Anonymous

        A fanboy of who? Your steps are retarded. A fanboy is someone who has all the devices, loves the company, and praises them while bashing the competition with illogical debate.

        I personally have an iPhone and was recently gifted an iPad. They’re by far the best devices in the market when jailbroken. I despise Apple, mostly stemmed from the stupid fanboys the company has produced. The hubris and stupidity of 90% of Apple users is also another turn off.

        Hrvoje has a valid point, it is you, Kok, who are clearly an upset Apple fanboy at his comments.

      • Kok Hean

        FYI, I was just trolling 🙂
        It’s an experiment to see what people will react like. And my name is not Kok.

    • You have problems….

  • Anonymous

    My head hutlrts.. Too much info!

  • do you guys honestly lose your chargers all the time? who cares about the price of those things? ive had 1 charger.. the one the phone came with… ive had it since i bought the phone… i remember where i leave it… and i dont lose it because im not an effing retard

  • firefly

    Order a cheap knockoff of this charger from DX and you will experience EMI. Using the touch screen when charging is really messed up as false touches will be registered along with your fingers. EMI affects all modern day touch screens not just iPhones.

  • Getittogether

    It’s pretty obvious he doesn’t know shit about power supplies. No, this is not innovative, no, this is not ground breaking. It’s a decent small smps, nothing fancy, nothing special.

  • Jeff Herd

    Ignore the Powerless and Fake iPhone wireless chargers Always!