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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

#101

Post by listic »

austenallred wrote: post #73
palmeida wrote: post #57

Earlier quoted context omitted.

On ebay there are a couple that say genuine http://www.ebay.com/itm/Genuine-Original-AC-Power-Adapter-Ap... I ordered one yesterday (not from this dealer in question) that also said genuine. Let's see what they will send to me.

>On eBay >say genuine Having been an eBay buyer/seller for a long time, I would put way less stock in someone on eBay saying a product is "genuine" than you appear to be.

I've been buying some ThinkPad chargers on eBay and never encountered outright fraud. When they say genuine, they really are. Otherwise they use different words.

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

#102

Post by kens »

yourapostasy wrote: post #84
jloughry wrote: post #46

An interesting feature of switched-mode power supplies like this is that they'll run on DC input, if that's all you have! DC passes right through the bridge rectifier into the chopper---not sure how happy the PFC circuit would be about that---and the rest of the circuitry works as usual. If the DC supply voltage is high enough, it'll work.

Please forgive the ignorant questions of a software guy that probably have blindingly obvious answers to a EE. Does this mean that theoretically, I could attach a 18V/18.5V [0] DC power source (like a solar panel array running into a DC-DC converter) to the prongs and as long as I can supply about 100W/8.5A my MacBook Pro will boot? [0] http://apple.stackexchange.com/questions/111250/how-to-charg...

Chargers require a minimum voltage to work. They typically say 85V and might work with lower, but I expect 18V is way too low. I'd also be very nervous about feeding DC into a PFC circuit (which is designed to track the AC waveform) - does anyone know for sure what PFC does if you feed it the wrong frequency? (Someone else asked about 400Hz aircraft power too.)

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

#103

Post by craigjb »

yourapostasy wrote: post #84
jloughry wrote: post #46

An interesting feature of switched-mode power supplies like this is that they'll run on DC input, if that's all you have! DC passes right through the bridge rectifier into the chopper---not sure how happy the PFC circuit would be about that---and the rest of the circuitry works as usual. If the DC supply voltage is high enough, it'll work.

Please forgive the ignorant questions of a software guy that probably have blindingly obvious answers to a EE. Does this mean that theoretically, I could attach a 18V/18.5V [0] DC power source (like a solar panel array running into a DC-DC converter) to the prongs and as long as I can supply about 100W/8.5A my MacBook Pro will boot? [0] http://apple.stackexchange.com/questions/111250/how-to-charg...

Not an ignorant question at all! This is actually a subtle problem in switching regulator design: high duty-cycle operation and efficiency. Basically, if you input a voltage very close to the output voltage, the switch part of a switching regulator must be always or near always closed. And, any inefficiencies such as voltage drops in the power path are visible in the output.

Being Apple, I'm sure it has 100% duty cycle operation. However, it's likely not optimized for hat (uncommon case).

[edit] as the other comment points out, my comments forgot about the PFC circuit. But on switchers without this, near output voltage input is possible.

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

#104

Post by ericd »

bbatha wrote: post #78
throwaway420 wrote: post #30

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…

Leaving a loop before wrapping the small end largely fixes the problem with the cables. Like so [1]. Though I shouldn't have to do it the first place. 1: http://www.tested.com/tech/5480-how-to-properly-coil-a-macbo...

I never wrap up my cables, it's still happened to every single one (about 4).

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

#105

Post by masklinn »

trymas wrote: post #95
robin_reala wrote: post #52

Earlier quoted context omitted.

I’ve never even had that. Sold a heavily used 2008 MacBook with its original charger last month with no signs of fraying or problems. I’m yet to have a charger die on me in any way.

I've seen that from some models made in ~'08-'09, the cables do not fray. I have 2013 rmbp 13" I have handled my charger with great care avoiding as much twisting ant touching as possible, and after around 20 months, cable isolation just tore up by touching it.. It seems that cable isolation is made of such plastic, that it completely degrades after some time..

Haven't had the issue with computer cables, but had the exact issue with iphone cables. The plastic apple uses for their cables is just weird, with friction or stress (just the stress of looping it around) it seems to gain a slightly rubberised texture, bulk up and ultimately come apart over time. I do have hints on that on a magsafe cable-end, close to the magsafe where the little plastic clip usually sits there's a lot of friction and the cable has gone dark-gray, whereas on the rest of the cable the clip can just slide along.

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

#106

Post by austenallred »

listic wrote: post #101
austenallred wrote: post #73

Earlier quoted context omitted.

>On eBay >say genuine Having been an eBay buyer/seller for a long time, I would put way less stock in someone on eBay saying a product is "genuine" than you appear to be.

I've been buying some ThinkPad chargers on eBay and never encountered outright fraud. When they say genuine , they really are. Otherwise they use different words.

They usually work, but I've never seen a legitimate name brand coming from Hong Kong via eBay. My experience was mostly in sporting equipment, and the stuff that I ordered looked and smelled like it was "Adidas" or "Nike," and even said "Nike," but it obviously wasn't made by Adidas or Nike.

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

#107

Post by ericd »

Sakiina_ wrote: post #81

Anyone here heard of the Magsafe saver? https://www.indiegogo.com/projects/lightning-magsafe-saver-p... This is what I got-- took an eternity to get to me, but it works well enough. I wrap my cables. I had my Macbook Pro for two years, abused it, charger was fine. I sold it with the Macbook when I moved back Stateside after living abroad. My next charger broke, because my kitten decided it made a great teething chew.…

As another option, white sugru works very well, and lets you taper down the amount to spread the stress over a larger area.

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

#108

Post by [deleted] »

Sakiina_ wrote: post #81

Anyone here heard of the Magsafe saver? https://www.indiegogo.com/projects/lightning-magsafe-saver-p... This is what I got-- took an eternity to get to me, but it works well enough. I wrap my cables. I had my Macbook Pro for two years, abused it, charger was fine. I sold it with the Macbook when I moved back Stateside after living abroad. My next charger broke, because my kitten decided it made a great teething chew.…

[deleted]

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

#109

Post by toyg »

tomcam wrote: post #100

You know what's not surprisingly complex? My feeling about how screwed I felt when I got the Macbook and its charger consisted only of straight-to-plug wall wart, power cord to Mac, as opposed to cord-to-wall-wart, wall wart, power cord to Mac. They halved the length of the cord while forcing you to stick your wall wart right into the socket, crowding out other cords if it's on a small power strip. That and the fact…

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...

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

#110

Post by listic »

austenallred wrote: post #106
listic wrote: post #101

Earlier quoted context omitted.

I've been buying some ThinkPad chargers on eBay and never encountered outright fraud. When they say genuine , they really are. Otherwise they use different words.

They usually work, but I've never seen a legitimate name brand coming from Hong Kong via eBay. My experience was mostly in sporting equipment, and the stuff that I ordered looked and smelled like it was "Adidas" or "Nike," and even said "Nike," but it obviously wasn't made by Adidas or Nike.

Aren't the actual, truly genuine Lenovo parts made there, too? Hong Kong is a Chinese territory.
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