“Disassembling Apple’s diminutive inch-cube iPhone charger reveals a technologically advanced flyback switching power supply that goes beyond the typical charger. It simply takes AC input (anything between 100 and 240 volts) and produce 5 watts of smooth 5 volt power, but the circuit to do this is surprisingly complex and innovative.” Quite fascinating, although I’m not sure just how much the mentioned advantages really matter beyond bragging rights.
Now, if only regulations about microUSB as the standard power socket were a bit more throughout, specifying this port on the device itself.
They way are are, allowing for an adapter,it’s only somewhat better (and certainly doesn’t preclude from the usual dramas with incompatibilities)
To me it just looks like the apple power supply uses a bunch of filters. I’ve only taken a few classes in ee though and don’t know very much about power supplies.
I’d say you are onto something based on the article:
“Apple’s power adapter is clearly a high-quality power supply designed to produce carefully filtered power”
There are millions of these produced everyday. They’re in every CFL light globe you buy. They’re also in the new LED lights you can buy these days. You can also get the the circuit from a multitude of online suppliers for less than a couple of bucks. So why are they so expensive? Because soon as you put a picture of an apple with a bite taken out of it on it, you can times the cost by fifty!
So what’s so “technologically advanced” about it?
I dunno, maybe it’s in comparison to the basic chargers which used to come with the cheapest phones – they were just a transformer, a couple of diodes and a capacitor. No regulation, no filtering. I don’t know if they’re still around though…
You should really read the previous post on his blog for comparison:
http://www.arcfn.com/2012/03/inside-cheap-phone-charger-and-why-you…
I agree you.
There’s no hi-tech feature in this circuit at all… All of these are common electronic components in a common switching power supply design. Delivering 5VDC up to 5W is fairly easy to achieve. Otherwise compare my laptop’s power supply that delivers 18V @ 6.5A (117W): it is not much bigger than the iPhone’s charger (considering its high power features).
The only innovation I see is the fact of distributing components along the 3 dimensions instead of distributing them in 2 dimensions, as usual.
Call me crazy, but I liked the old power adapters based on a the transformer/diode bridge/filter combo, with a dissipative regulator if you really need a clean signal at the cost of some efficiency.
For some reason, PWM-based adapters tend to make painfully audible high-pitched sounds when they are plugged in, but do not deliver current. I have to admit that this reminds you to unplug them, though…
Edited 2012-05-22 09:55 UTC
Call _me_ crazy but I would like them to shut off when there isn’t something connected.