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Macbook charger teardown: surprising complexity inside Apple's power adapter

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Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#12

My takeaway from this is that the $80 Apple charger is definitely safer and has higher-quality components than the $12 cheapo Chinese charger, but not nearly so much better that it solely explains the price difference, and that Apple is making a healthy margin on these things. So my question is, is anyone selling a quality charger without the Apple tax? Is there anyone making, say, $40 chargers that have the componen…

I doubt it, since the magnetic connector itself is patented, and they apparently don't license it— which is why the BatteryBox connector is such an awkward hack: https://www.getbatterybox.com/shop

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#13
post #3

Hidden gem in this article is a comically bald-faced lie from Steve Jobs: > "That switching power supply was as revolutionary as the Apple II logic board was. Rod doesn't get a lot of credit for this in the history books but he should. Every computer now uses switching power supplies, and they all rip off Rod Holt's design."

It may not quite be true, but it's not necessarily a lie. People often don't realise where an invention came from.

You're not really doing Jobs any favors. Instead of saying Jobs was a liar, you're saying he was an ignorant liar.

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#14
I really hate how weak they made the strain relief. I found mine frayed within a year of use (in and out of bags and often hastily "wrapped up" in exactly the way the device suggests one should by form... but which everyone advises against). So I did what any enterprising hacker would and tore it open to strip and re-solder the connection... only I found super-thick solder points and don't have a strong enough gun to de-solder them.

Ended up just blowing cash on a new brick.

I was rather impressed by how many components they stash away in these things. I just wish the cables themselves were a little more reliable. They're otherwise fine devices.

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#15

Earlier quoted context omitted.

It may not quite be true, but it's not necessarily a lie. People often don't realise where an invention came from.

You're not really doing Jobs any favors. Instead of saying Jobs was a liar, you're saying he was an ignorant liar.

"Liar" is too strong a word here. It's a misconception at best. Jobs would not have known the history of switching power supplies.

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#16

Earlier quoted context omitted.

It may not quite be true, but it's not necessarily a lie. People often don't realise where an invention came from.

You're not really doing Jobs any favors. Instead of saying Jobs was a liar, you're saying he was an ignorant liar.

I disagree - a lie is told knowingly. If you say something untrue without knowing it is untrue, it isn't a lie.

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#17
post #4

Fascinating. The magsafe connector is awesome in preventing something snagging the cable from dragging your laptop along with it. But, as the article says, reliability is a problem. The thing is definitely not toddler-proof. I have a 2012 Macbook Air, and I'm on, I think, my fourth charger.

Had a 2011 Macbook Pro. Was always very nice to the charger, never abusing or dropping it. But Apple's decision with all their cabling to not incorporate strain relief was frustrating. I went through four chargers in four years. Why does Apple continue to ignore strain relief on their cabling?

Odd. I have a 2011 MBP as well and over four years of constant use in school (plugging in the charger at the dorm, unplugging and throwing it into my bag, plugging it in in class, removing, etc. in various places) it's held up. I use it now with my newer Macbook (just needed to get the magsafe 2 adapter dongle).

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#18
This is a pretty interesting article! I raised more than my fair share of eyebrows by telling people I'm not really surprised with this kind of complexity (note: I'm an EE by formation, I took a frickin' two-semester course on power supplies) but that it doesn't fully justify the price difference.

Also, Jobs was a blatant liar :-). The SMPS in any modern computer is based on a standard topology that Rod Holt -- though a brilliant engineer in his own right -- didn't invent. I don't remember the specific details, but it's based on a flyback design that was certainly well-known at the time.

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#19
post #3

Hidden gem in this article is a comically bald-faced lie from Steve Jobs: > "That switching power supply was as revolutionary as the Apple II logic board was. Rod doesn't get a lot of credit for this in the history books but he should. Every computer now uses switching power supplies, and they all rip off Rod Holt's design."

News for me too. I had read that quote in a different context and had assumed it to be true. Good little gem to learn.

Re: Macbook charger teardown: surprising complexity inside Apple's power adapter

#20
post #3

Hidden gem in this article is a comically bald-faced lie from Steve Jobs: > "That switching power supply was as revolutionary as the Apple II logic board was. Rod doesn't get a lot of credit for this in the history books but he should. Every computer now uses switching power supplies, and they all rip off Rod Holt's design."

It may not quite be true, but it's not necessarily a lie. People often don't realise where an invention came from.

It's more likely a bold overstatement made by a superficial onlooker. Wozniak describes the same power supply here: http://archive.woz.org/letters/general/35.html , in these terms:

Other hobby computers of the day used inefficient power supplies. The Apple ][ was the first computer ever to use a plastic case. The heat buildup using even my own power supply design (inefficient type) would have been too great. Steve tapped an Atari engineer, Rod Holt, to design a switching power supply that was much more efficient and generated less heat. Rod also keyed us into the fact that the plastic case wouldn't conduct heat well. At this point in time we took pride in being the first computer to use a switching power supply. Steve was proud of the fact that we didn't need a fan and seems to hold to that ideal to this day.

So:

* Holt designed a switching power supply which employed a patented addition to an otherwise well-known topology (it's a flyback power supply).

* Computers nowadays "rip off" the same design that Holt ripped off, they all use flyback PSUs.

* I doubt that the Apple II was really the first computer to use a switching-mode power supply, but linear supplies were pretty common among hobby computers back then. The Commodore 64 had one, for instance.

The downvoted comment about Jobs being an ignorant liar is probably spot-on.

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