MacBook charger teardown: The surprising complexity inside Apple's power adapter (2015)
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I recently got a 30W Anker USB-C charger that is as small as the really old iPhone chargers, less than an inch cube, and it charges my M1 MacBook at full speed. It's far less than a third of the size of this 90W charger.
I'd love to see a teardown of that, too.
https://www.promate.net/blogs/blog/what-is-gan-technology
Half of my company has done the same and mostly Anker too. I got the charger/battery combo, as it is amazing for travel.
I think that's what the Y capacitor does (also pictured in the article): https://www.vicorpower.com/resource-library/articles/back-to...
Before that change I did end up throwing away a PSU that was causing tingling on my laptop. I don't know if that's a manufacturing flaw or damaged wiring.
The educated guess as to the mechanism is 'floating ground' (the white wire has a potential versus earth ground). It causes weird behavior in house wiring, particularly ones that have had iteration in their wiring (remodels, additions). Then there's the one where LED lights turn on even if the switch is off, but I think that's a separate phenomenon from floating ground.
It happens even in a properly wired building without faults, since a class 2 PSU needs a path for EMI on the secondary side to be dissipated, and due to the lack of a dedicated ground, the only choice is to connect both phase and return to the secondary circuit via a Y capacitor.
A common downside of that is a stray voltage of up to half your mains voltage on any conducting surface of your device, but it’s harmless since it’s not capable of sustaining any meaningful current.
Apple's power supplies for MacBooks do have a grounding pin, but the default duckhead adapter they ship with usually doesn't leverage it, so you end up with a class 2 power supply and the buzzing sensation.
> that you can hear the buzzing sound too if you put your ear very close.
I've found Apple power adapters to be pretty good in that regard, unlike some third-party power supplies that I can hear across the room. If I can only hear the noise when I put my ear next to the supply, I can just not do that :)
Do the Anker one's come with international plugs? I didn't see any indication on their product pages that they come with the adapters. Nor could I find them for sell.
Oh well, I'll probably follow your advice or checkout a different brand. Thanks!
https://www.anker.com/products/a2046?variant=42448630612118&...
Don't think I've travelled with more than one charger since phones switched away from micro-USB.
Mind that a lot of chargers do weird power allocation things when multiple devices are connected. You probably aren't going to get all 150W to the laptop with four devices connected; depending on the charger and what port you're connected to, you may get much less.
Of course, outside of fairly niche situations, this isn't going to make a practical difference to your life. :D
MacBook Pro models are able to fast charge at 140W (M1 onwards). Even the original M1 MacBook Air can charge at 45W[0]. I don't think it's accurate to say that the 30W Anker charger can charge your "M1 MacBook" at "full speed".
0: https://www.reddit.com/r/macbook/comments/kdpxmm/psa_m1_macb...
Apple supplies a 30W charger in the box, so I think it's fair to say that a third-party 30W charger is "full speed" (in the sense of "as good as the stock one", if not full speed in all potential scenarios GP might or might not care about).
When iPhones shipped with chargers they were only 5w despite being able to charge from faster chargers.
Wattage aside, I'm sure there's more to it than meets the eye. Afterall, Apple are not stupid, smaller charger means less plastic casing and less packaging means simpler manufacturing ... no doubt the Apple ones are the size they are for a reason.
Source: have a HP laptop with a brick-size power brick.
That reason might well be "because it's slightly cheaper to build a larger charger and most people wouldn't be willing to pay more for a device that comes with a compact one in the box".
You can't just order 15M components, built to a custom spec, and get them reliably overnight. Hence Apple have been working to scale supply lines, work with suppliers (and their suppliers) and ensure both quality and other factors (like environmental concerns).
Anker can go out of stock and then produce again when things stabilize. Apple can't stop selling Macs for 3 months without a major global crisis.
After getting the M1 I'm typing this on I asked if a MagSafe 1-MagSafe 3 adapter existed. <https://np.reddit.com/r/applehelp/comments/10duooq/i_want_a_...> I felt foolish when I realized that being able to charge from USB-C meant that I could use any old charger and a USB-C cable for the times when I'm away from the stock Apple charger that came with the computer. Bonus: No more dealing with the Apple cable to the MagSafe 1 plug that inevitably lost its sheathing and exposed wires within a year.
https://www.chargerlab.com/teardown-of-anker-30w-usb-c-gan-5...
Not as small/cheap as other GAN chargers, though.
> The ironic thing about the Apple Macbook charger is that despite its complexity and attention to detail, it's not a reliable charger.
> The Macbook charger is an impressive piece of engineering, even if it's not as reliable as you'd hope. On the other hand, cheap no-name chargers cut corners and often have safety issues, making them risky, both to you and your computer.
Given the above quote from the conclusion section, after a lengthy Why you shouldn't get a cheap charger section, my takeaway is that the author still endorses the Macbook charger.
The actual bricks themselves have been pretty reliable.
> Macbook chargers also fail due to internal problems. The photos above and below show burn marks inside a failed Apple charger from my collection.
https://forrestheller.com/Apollo-11-Computer-vs-USB-C-charge...
That's a great little factoid that I'm going to use at every opportunity.
Though, that's not really more convenient than carrying a power adapter around, so they didn't have to do it that way.
Ungrounded connection sometimes causes tingling, a common enough problem that this Amazon 3-prong head even mentions it in the title: https://www.amazon.com/Grounded-Duckhead-Apple-Mac-Adapter/d...
They also do sell a US 3-prong extension cord.
Transistor oscillation and rectifying converter power supply system U.S. patent 3,040,271 is filed by Joseph E. Murphy and Francis J. Starzec, from General Motors Company.
Still, it's always fun to read Ken's blog.
Which, in the worst case, will start a fire that will burn down your house. It's not worth the risk of using cheap chargers; buy from a reputable brand
Cheap chargers skimp on safety. Entirely possible they fail unsafely.
I once bought a cheap no-name Android charger and it literally exploded after a year of use. Hot metal droplet landed on phone screen which was a cute reminder for a while (until later the screen cracked through where the droplet was).
That tingly feeling has been found by me on plenty of different device power supplies. That is high voltage getting passed to the low voltage side - a sign of bad design. The last two devices I remember were (1) a multi-USB charger which tingled but seemed to work okay and (2) cheap speakers for a PC where the voltage hum was causing serious problems with other devices connected to the PC (and hard to diagnose cause).
I'm amazed how many unsafe electrical devices we own: the safety standards are not working in my experience. And I think New Zealand has stronger standards than the US.
Safety standards aren't the issue, their enforcement is. In most countries, agencies overseeing the safety of electrical consumer equipment, are perpetually understaffed and/or underfunded.
So they don't have the resources to take a good sampling of what's on the market, and (thoroughly) test those samples.
As a result, it's mostly especially bad gear (discovered by accident, # of incident reports etc) that gets attention. Or becomes subject of a recall.
What's left is relying on paperwork, and manufacturers or importer's integrity. Which (as you note) varies a lot depending on where you look. Especially in this day & age of people buying cheap junk directly from abroad through Ebay, AliExpress & co. Not to mention fakes, or no-name manufacturers that pop up & disappear overnight.
That's also why many laptops (such as Macbooks) come with an "intelligent" charging feature that will limit charging to 80%, only charging up that last 20% when it thinks you'll need it
I often wonder why I buy a third party charger for an expensive phone
Then I noticed that my Ginuwine Aapel Charger made in Caulifloweria made my phone's touch screen literally buzz when I touched it.
Never used a cheap charger since. Why break a 500€ plus device by saving 20€ on a charger?
Like a relative of mine who ruined an expensive (500€+) brand name suit jacket by hanging it on a 50 cent wire hanger and now the shoulders have permanent very visible indents. Spending 5€ on a proper hanger would've been enough.
"The ironic thing about the Apple Macbook charger is that despite its complexity and attention to detail, it's not a reliable charger."
That's the funny thing about engineering. I have built a lot of things and have used a lot of tools across the entire spectrum from shitty garbage cast out of pot metal (think Harbor Freight, Aliexpress etc) to five-figure Serious Tools for Serious People (cranes, large format cutters, thrusters, advanced measuring equipment etc.) From that experience I can say confidently: It is impossible to know for sure if something is reliable until you actually use it for an extended period of time.
I have seen countless absolute hack-job products made of pot metal last decades in a marine environment and I have seen a similarly endless number of beautifully engineered products made of top-tier materials fail catastrophically. Sometimes the shitty product will have two failures that miraculously cancel each other out, or it will rust to shit and keep working, or it will fall to pieces but can be easily epoxied back together to get another ten years out of it. That's the other side of the coin of perfection - repair. With the beautifully-engineered product made with quality materials? Nine times out of ten, fuhgeddaboudit. If you have a serious failure, you're fucked. There is no practical economic way to repair that Mac charger, or your fried fancy oscilloscope, or any advanced motor, or unibody, or virtually anything made of titanium, carbon fiber, et cetera. Give me the cheapest version of your object, however, and I can repair it using only crap from Walmart.
Don't get me wrong - give me infinite money and replacements and I will take your beautiful object every time, and in many cases today I have "infinite money" given the price of the product. An Apple Silicon Mac is cheap to replace and it is head-and-shoulders engineered above the rest; it is the pinnacle of all human engineering through history, in my opinion. If mine breaks I will just buy a new one. The problem is that as the world grows richer, this has gone from a luxury attitude to one more people can have each year, and the proportion of beautiful, perfectly engineered objects steadily rises. A hundred years ago no such objects existed. Thirty years ago, they were rare. Today, you can buy anything, from drills to cameras to new unibody cars that are beautiful and flawless and engineered to perfection and completely uneconomical to repair. There are exceptions, wear item parts, manufacturers with repair guides... but they are on the way out. Make no mistake, the moment anything can become a perfect sealed lifetime part, it will.
In the distant future, worlds ahead of endless energy and materials, long after the idea of popular repair dies, I only hope it will be reborn as a hobby; bored humans instructing bored robots to choose the inefficient path, to repair and not replace.
As far as dangerous home electronics repairs go, CRTs were pretty much the top of the list and they're all but gone now. Normal 110v work is rarely that dangerous even if you mess it up and most things aren't even 110v anymore - lots of consumer electronics just take a standard 5 or 12VDC or whatever. Besides, 90% of electronic repair is "find the burnt, hot or damaged component and replace it"; you're not exactly designing your own powerboard from scratch. Hell, there are hundreds of thousands of products on Amazon with hot 110V metal cases, which is pretty much the worst imaginable thing, and yet few people get injured by them - the reality is that whatever sin you possibly commit in your DIY repair has a tiny chance of causing any real world injury.
But more to my point, these days doing your own repairs are unusual, sixty years ago it was often included in the instruction manual. Even the cheap shitty stuff is less cheap and shitty than it once was; smaller, more efficient parts, SMD components, "sealed lifetime" bits, unrepairable materials etc.
Repair is more efficient than replace! You're replacing something in either case. But in a repair, you replace less: only the part(s) that failed.
Reasons we don't (in many cases) are 3-fold:
1) Products are designed for 'easy'/efficient/cheap manufacturing, not to be easily repairable. "Repair-friendly" is often near the bottom on consumers' wishlist.
2) Manufacturers have become laser-focussed on that (successfully!), such that some devices literally cost pennies. Combined with
3) We value human time above machine/production time. So in most cases, the cost of [human time spent on repair] exceeds cost of [just buy replacement device].
Maybe "repair robots" will change that equation some day? Only if those are cheap & skillful enough.
>There is no practical economic way to repair that Mac charger, or your fried fancy oscilloscope, or any advanced motor, or unibody, or virtually anything made of titanium, carbon fiber, et cetera.
The issue lies in their superiority. The modern powerboard which filters and slices is far superior to its simple cousin. Titanium, carbon fiber, advanced composites permit the impossible. Elegant unibodies provide strength, cooling, simplicity. Sealed black boxes bring reliability, weight, strength. None of those things can be repaired economically. We are a rich world now, getting richer by the minute. The objects that surround us are sleek, powerful, reliable, perfect. I suspect nothing can stop this tide now. The march of time will forge ever more perfect objects and leave us useless in its wake.