
Apple iPhone charger teardown (2012) - ofrzeta
http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html
======
sephamorr
Power engineer here. Something that is not apparent is that many small power
supplies are limited in power handling not by the components, but by maximum
safe touch temperatures for meeting regulations (probably around the 10W
level). Therefore making a more efficient power supply means that you can
package it smaller since the heat needs lower surface area to dissipate
safely. Right now, gallium nitride MOSFETs are gaining popularity allowing for
higher efficiencies in power conversion, and some wildly high power densities
for USB chargers. I'm a fan of ravpower's 30W USBc supply which is about one
cubic inch with folding prongs.

~~~
solarkraft
Yet there seem to be no designs with any ventilation. Why is that? Are heat
sinks not allowed because the case is (usually) not grounded?

~~~
lloeki
Useful ventilation means holes through which someone could insert a thin
metallic part (wire, needle...)

Never underestimate the ingenuity of fools. The safest design is one without
holes.

~~~
dogma1138
You don’t even need people inserting anything.

Dust is a problem on its own it can ignite from ESD and the charing causes
carbon built ups that eventually cause a short.

Even when it doesn’t ignite from ESD it can change the capacitance of circuits
which can cause a flash.

This is compounded even more by the fact that many dust particles in cities
can be conductive carbon particles form combustion, platinum and other metals
form catalytic converters and fine metal particles from things like car
brakes, roads and wheels are all over the place.

A lot of that black/dark grey dust that can settle around windows and other
leaky parts of your house in a city isn’t dead skin and dirt.

------
klodolph
I’m constantly amazed by these things in daily life. The charger is just
barely large enough safely house a USB jack, and that safety margin is large
enough to fit a high-efficiency converter.

If you are curious how it works, the Horowitz and Hill book, 2nd ed, has an
extended section dedicated to describing how the power supply for the Apple II
works. The iPhone uses the same technology, broadly speaking. Switch-mode
power supplies were fairly new at the time, and older computers will generally
use bulky, inefficient linear power supplies.

Every once in a while I come across something from before the era of small
SMPS, like a constant-voltage transformer that was bundled with my color
photographic enlarger. The idea is that you regulate the voltage for the lamp
to make the light color more consistent, but since the technology was old, it
consisted of a massive, heavy ferroresonant transformer. I ended up selling it
for scrap.

The general way that you make power supplies smaller is by increasing the
frequency they run at. For SMPS, this means increasing the switching
frequency, but there are also some AC standards that run at higher frequencies
in places where space and weight is at a premium. For example, AC power within
an aircraft might run at 400Hz rather than 60Hz. The transformers are
correspondingly smaller.

~~~
amelius
But higher switching frequency means more losses and thus higher temperature.

------
sjwright
The world is a better place when companies like Apple do stuff like this
properly. Besides, I’d guess that well over 95% of the chargers Apple ships
are bundled with a device. Possibly 99%. So the retail cost of the charger on
its own is beside the point.

If you want a cheap aftermarket charger, consider products sold by IKEA. While
I can’t say it’s an immutable truth, IKEA electronics tend to be well
engineered considering their low cost.

~~~
skunkworker
IKEA LADDA AA and AAA batteries are some of the best I've ever bought and for
the price are very hard to beat.

There are some reports and writeups that suggest that LADDA 2450 AA/900 AAA
rechargeable batteries are the same as Panasonic Eneloop due to extremely
similar characteristics and the fact that they very likely come from the same
factory in japan because only one makes Ni-MH low discharge. For $6.99 per 4
batteries I have yet to find any that can beat these and I have been using
some for years without any noticeable drop in capacity yet.

[https://www.slrlounge.com/panasonic-eneloop-vs-ikea-ladda-
ar...](https://www.slrlounge.com/panasonic-eneloop-vs-ikea-ladda-are-they-the-
same/)

~~~
ksec
They are basically OEM ( at least it was in 2018 / 2019 ) from Panasonic. But
not all Eneloop and in fact LADDA are from Japan. Panasonic do make Eneloop
from China and they are of slightly lower quality than the one produced in
Japan.

I believe there are a few variant / types / size of LADDA, and there are one
or two make in Japan.

Unless you are perfectionist you would want the best one from Japan. Otherwise
most LADDA are good enough for 99% of its intended usage.

------
supernova87a
2 points:

1) The blog touches on it, but can you imagine the temptation of shady (and
non-shady) companies out there to try to engineer a cheaper version or to cut
corners to gain some of the margins charged for such a seemingly-simple piece
of hardware?

2) Do you remember 20 years ago, 5-10VDC power supplies for computers used to
be this gigantic ugly black brick with cooling fins that weighed 2 pounds and
had embarrassing Apollo-style connector plugs? Amazing what miniaturization
has achieved.

~~~
kens
Author here. I've written a couple of articles about counterfeit chargers. You
are correct; people cut every corner possible to make a counterfeit charger
that looks exactly like an Apple charger. (If you buy a $3 Apple charger on
eBay, this is what you're getting.) The power quality of the knockoffs is
awful. They also ignore safety, so the fake chargers occasionally kill people.

For point 2, I also wrote an article in the IEEE Spectrum about the history of
switching power supplies and how we ended up with such tiny chargers.

Links: [http://www.righto.com/2012/03/inside-cheap-phone-charger-
and...](http://www.righto.com/2012/03/inside-cheap-phone-charger-and-why-
you.html) [http://www.righto.com/2016/03/counterfeit-macbook-charger-
te...](http://www.righto.com/2016/03/counterfeit-macbook-charger-
teardown.html) [https://spectrum.ieee.org/computing/hardware/a-half-
century-...](https://spectrum.ieee.org/computing/hardware/a-half-century-ago-
better-transistors-and-switching-regulators-revolutionized-the-design-of-
computer-power-supplies)

~~~
aurea
How can I know whether I have a real of fake charger?

~~~
danieldk
Directly order from Apple, Samsung, etc. Definitely do not trust _anything_
that comes off Amazon or eBay.

~~~
aurea
Yes, but what if I already have a charger and I don't know where it came from?

~~~
danieldk
It is probably hard to say, from the outside they often look legit. I have
seen one once, but it became more apparent when we compared it to a genuine
charger (usually the print is off in some way). Since counterfeit chargers
typically have fewer components, apparently weighting the charger can also
help finding counterfeits:

[https://www.electricalsafetyfirst.org.uk/blog/how-to-
spot-a-...](https://www.electricalsafetyfirst.org.uk/blog/how-to-spot-a-fake-
apple-charger/)

Of course, it's probably not beyond them to add some weight to make you
believe it is real.

I guess if you have the right tools, you could also measure output quality.

~~~
lloeki
They do add weight (and go through the trouble of implementing ring structures
to fake writes)

[https://youtu.be/g8ovFkd8myE](https://youtu.be/g8ovFkd8myE)

------
iszomer
Are Anker chargers engineered well enough to match?

~~~
danieldk
Can't say anything about Anker chargers. But I have been somewhat disappointed
by their engineering. It is well known that USB 3 can cause interference in
the spectrum used by WiFi and BlueTooth (2.4-5GHz), but their USB-C hubs seem
to be particularly bad causing a lot of interference. I had one that would
reliably disturb wireless keyboards, etc. I did not have the same problem with
Apple or Aukey USB-C hubs/dongles.

The Amazon reviews are also full with people who encountered interference:

[https://www.amazon.com/product-
reviews/B01D0WE99C?reviewerTy...](https://www.amazon.com/product-
reviews/B01D0WE99C?reviewerType=all_reviews)

~~~
mhh__
If it interferes that badly shouldn't the FCC or similar be having a word?

~~~
zz0rr
I have no idea about the interference claim, but incidental radiation within
an ISM band is allowed to a great degree, that's the idea of ISM. The device
may have been tuned to switch in that band to keep it affordable.

edit- I think I mis remembered this, I can't find an easy to interpret rule or
graph that gives an incidental radiation pass unless you're a specific
category like wireless charger. it could also be explained by conducted
emissions into the laptop that other devices do better with, or just a legal
level of interference that happens to be at the high end

------
ximeng
I have more of a problem with iphone charging cables - the official ones
disintegrate, and both official and non-official seem to have problems with
the fourth pin getting corroded over time and the cable failing.

~~~
ValentineC
I'm used to Lightning cables breaking, but it's a pity that the thin,
charging-block-to-MagSafe section of my MacBook charger has corroding
insulation that Apple refuses to take responsibility for.

Some of their Geniuses have even tried to blame me for not storing it
properly.

~~~
PascLeRasc
Do you have access to heat shrink and a heat gun? That fixed my insulation
issue.

~~~
ValentineC
I bought heat shrink in a number of sizes, but haven't managed to stretch any
to fit through the MagSafe 2 connector.

------
chrisma0
I always wondered what the specific differences between expensive original and
alternative cheaper chargers were and whether the price differences were
justified... "The Apple charger is higher quality and I estimate has about a
dollar's worth of additional components inside. But it sells for $20 more."

~~~
jmiserez
And yet _all_ the USB chargers I use are Apple chargers bought directly in an
Apple store. Peace of mind that the house won't burn down is definitely worth
$20 per charger.

------
kccqzy
Previously on HN:
[https://news.ycombinator.com/item?id=3996171](https://news.ycombinator.com/item?id=3996171)

~~~
myspy
I‘m old. I remember reading that article eight years ago.

------
kccqzy
> Two other R-C snubbers filter the diode bridge, which I've only seen
> elsewhere in audio power supplies to prevent 60Hz hum; perhaps this enhances
> the iTunes listening experience.

Is this really the reason? That when engineers are designing _chargers_ , they
are considering the music listening experience?

~~~
dmitriid
Old Apple used to care about things like this. One of their primary customers
were audio engineers and sound designers.

~~~
dangus
And their customers still are audio engineers, it’s just that they also have
more general consumers.

The new Mac Pro rack mount version basically makes no sense unless you do
professional audio. Why else would anyone need a quiet rack mount server with
really bad component density per U that has no lights out management?

It’s because it’s a studio rack mount workstation intended to coexist with
other rack mount audio hardware.

Apple’s hardware seems overpriced until you consider the license cost of Avid
ProTools compared to paying for Logic Pro once. Apple is still quite aware
that audio professionals are an important niche customer.

------
5etho
FYI only chargers that one one day just stopped working was made by Apple.
Good they are well enginereed, bad that they just broke.

------
amelius
They didn't even test it under different loading conditions and with
transients on the input?

~~~
PascLeRasc
They did, just in a different article:
[https://www.righto.com/2012/10/a-dozen-usb-chargers-in-
lab-a...](https://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-
is.html)

------
rkagerer
Looking forward to seeing the Samsung teardown for comparison.

~~~
kens
I wrote about a Samsung cube charger here:
[http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-
ap...](http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-
is.html)

The short answer is it is slightly less complex than the Apple charger, with a
completely different internal design, and it performs about the same.

