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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

#172
post #152
post #122

Earlier quoted context omitted.

I support around 300 Macs for work. In my extensive experience, the deal here is that people are FAR too rough and careless in winding up those charger cables over and over. Apple HAS implemented strain relief here and done their best to make the points of failure less vulnerable. Here's a tip: Instead of yanking the cable at a 90-degree angle and winding as tightly as possible, let the cable come out of the charger…

> Apple HAS implemented strain relief here That's not the same as implementing good strain relief. I used to work for a company that made medical devices. One of our products started with a cable with strain relief, and it kept breaking (a wearable monitor). We 'implemented better strain relief', and it kept breaking. It was revision D where we got it right and the cables stopped breaking. And if cables can't survive…

That's ludicrous. Other companies don't have this problem? Sorry, but I take care of hundreds of PCs. Other companies definitely do have this problem.

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

#173
post #122

Despite the visual appeal of their products, Apple normally does a very good job with prioritizing function over form except in this case with the charger wire being so fragile and thin. I know I'm not the most careful and delicate person in the world, but the failure rate here is ridiculous compared to other similar products I own. The end of the cable gets frayed every single time. Otherwise, Apple makes ridiculous…

I support around 300 Macs for work. In my extensive experience, the deal here is that people are FAR too rough and careless in winding up those charger cables over and over. Apple HAS implemented strain relief here and done their best to make the points of failure less vulnerable. Here's a tip: Instead of yanking the cable at a 90-degree angle and winding as tightly as possible, let the cable come out of the charger…

I can't agree with that. Someone at Apple fetishizes thin cables to a dangerous degree.

These power supplies aren't as obviously defective by design as an iPhone cable, but after looking at the amount of design detail and engineering directed at the power supply and MagSafe, the sacrifices made seem pretty insane.

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

#174
post #156

> The charger uses an advanced design called a resonant controller, which lets the system operate at a very high frequency, up to 500 kilohertz. Wonder what would happen if the 500 kHz signal would be fed to an antenna? Would that emit a signal, would it not work at all or become dangerous and probably highly illegal? Here is an example what an antenna for 500 kHz looks like: http://g0mrf.com/500kAntenna.htm

Switch mode power supplies are notorious emitters of radio frequency interference. There are regulations they have to pass and passing them is often one of the hardest parts of power supply design.

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

#175

Earlier quoted context omitted.

I'm one of those annoying people that has never had MacBook charger perish or fray, until very recently I still had a 2011 MBP and its original charger was fine. But yes I've seen people with dangerously broken chargers before, I have noticed they're often people with cracked phone screens - I wonder if they're perhaps people that are either more physically active with their hardware or perhaps more careless with loo…

I have a cat. None of my other charging cables are vulnerable except my macbook pro one. I've already lost two! Even if they made it easier to replace just the cable that goes from the adapter to the macbook it would be a big win for me.

>pet/child destroys electronic device >somehow manufacturer's fault

If Apple were to make a charger with steel-braided armor cable to prevent animals from chewing it, there would be a 250 reply thread on HN about how obnoxiously heavy and inflexible Apple chargers are. And some guy's cat story about how it destroyed the charger anyway.

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

#176
post #165

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> Otherwise, Apple makes ridiculously durable products Except for the first USB cables for iPhone5, those things only last a few months. First time I have had to buy three cables for charging one device within a year.

Did you know those are covered under your iPhone warranty? As long as you have a warranty (including AppleCare, so up to 2 years), they will replace the USB cable and headphones for free.

Didn't know that until it was too late... It did surprise me that they were so bad that year.

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

#177

Earlier quoted context omitted.

My earphones kept breaking (I use them while working out) so I reinforced the sensitive area with a heat-shrink wire wrap, like these: http://www.amazon.com/dp/B008WWC6FU It works wonders. I'm not sure this would work for Mac chargers because you couldn't get the sleeve over the ends, but it also works iPhone charger cables.

I used Sugru (sugru.com) to fix my mac charger and other things, my earphone cable is next.

I've used both shrink tubing and Sugru on iPhone cables. On the MacBook charger, just Sugru. Both will fail eventually. I find that typical shrink wrap is too stiff and creates stress riser. After a couple of years, my cables are more patch than original.

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

#178
post #156

> The charger uses an advanced design called a resonant controller, which lets the system operate at a very high frequency, up to 500 kilohertz. Wonder what would happen if the 500 kHz signal would be fed to an antenna? Would that emit a signal, would it not work at all or become dangerous and probably highly illegal? Here is an example what an antenna for 500 kHz looks like: http://g0mrf.com/500kAntenna.htm

That's one of the reasons the charger has a bunch of inductors and capacitors on the AC line, to keep interference from exiting the charger through the AC line. The metal shielding around the charger also helps.

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

#179
post #120
post #109

Earlier quoted context omitted.

Is this the new model? I got the 2012 version (UK) and got the modular charger with cord-to-wall-wart plus wall-wart-only...

Yes. It's the MacBook Air-like fanless one [1] with only 2 ports: headphone and USB-C. And half a power cable. And no MagSafe. Did I mention I'm a little bitter? [1] http://www.apple.com/macbook/

All of this is literally on the tech specs page. http://www.apple.com/macbook/specs

You can be disappointed, but if you're bitter, it's your own fault for not properly researching. Don't blame Apple, no bait and switch here.

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

#180
post #169
post #161

Earlier quoted context omitted.

Way back in my computer repair days, I used to commonly see macbooks with horrendously frayed and/or just generally poor condition chargers. While, other laptops didn't seem to have that issue nearly as often (although breaking the DC jack was a common problem for those folks, but that's a different issue). You shouldn't have to be tender and gentle with the power cable for your device... it should be durable and sta…

Great, so you explain how Apple's design is faulty, and how it could be improved. I think you'll find this is easier blustered about than done. PC chargers, for instance, are universally worse. A lot worse. This design already does the best job in the industry at handling hard yanks——that's what MagSafe is for. And it does fine with ordinary, expected use and abuse of the cable. And it does great with being thrown in…

> PC chargers, for instance, are universally worse. A lot worse.

This is an unsubstantiated claim not backed by any evidence. In fact, your original post speaks against your very claim - you advocate people be ginger with their chargers or risk breaking them.

> This design already does the best job in the industry at handling hard yanks——that's what MagSafe is for

You mean to say "that's what MagSafe was for". Magsafe is gone now... (although I would generally agree that type of connector is good).

> it does fine with ordinary, expected use and abuse of the cable

Clearly not the case, as evidenced by this thread here.

> And it does great with being thrown into a bag or dropped.

I can't speak to either way except with anecdotal evidence of having to replace far more macbook chargers than any other type.

> What it doesn't do, because that's impossible, is to magically become able to be yanked on 500 times and coiled as tightly as possible around itself, without ever wearing out

Somehow my Thinkpad's charger hasn't worn out, and I'm guilty of every laptop charger sin there is. The same holds true for my previous Dell laptop. These types of chargers are usually made from hard plastic, with a plastic cable. They don't fray the same way macbook rubber-y chargers do. In fact, Dell's chargers are designed specifically to be tightly wound around the charger and come with a nice rubber strap to hold it tight.

> Your implied accusation that "design aesthetics" have taken precedence over functionality and durability is unfounded

Perhaps, but it does seem so given all the anecdotal evidence in this thread. It looks pretty, but wore out far quicker than most should.

> The fact is that Apple's charger works a lot better and is a lot more durable than the competition.

This is another unsubstantiated claim, and/or is supported only by your proposition people treat their chargers with tenderness (which isn't going to happen).

Plain and simple - these things need to be designed to take a lot of abuse. If Apple can do that, great... but it seems they took a giant leap backwards with the new USB-C charger which will cause the infamous "broken DC jack" problem all over again.

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