It's pretty self-evident that the circuits are different. The phone normally operates from its battery, the amount of ripple present from a battery is zero. I'm not sure what source exactly you want me to provide to cite the fact that a phone has a battery, anyone knows that.

Also, typically a phone will use a buck converter (or perhaps buck-boost) to drop its voltage, rather than a switching regulator.

Some phones do have problems operating while plugged into crappy adapters (the power does pass through), the most common being that the touchscreens stop working.

> Yes, you got it. There's 1001 improvements that could be made to the RPi. If you made all of those improvements, it would not be affordable.

And yet any network switch you buy off the shelf for $15 comes with a workable power supply.

But yes, that is my point, the parent was asking for reasons why you wouldn't buy a Raspberry Pi, and the fact that it's got a shitty power system that tends to result in SD card corrupt is a major reason you should not purchase a Pi and prefer a properly engineered product. I think we're in agreement.

The Pi Foundation themselves cite the cost of the switching-mode power supplies on their alpha boards as adding $2 to the bill-of-materials cost, leading to their decision to remove them from production boards. Terrible anti-consumer move, how much have you spent on burned-out SD cards so that they could hit their $35 price point?

https://www.raspberrypi.org/blog/power-supply-confirmed-as-5...

Anyway, any random piece of electronics comes with a power supply. A $15 network switch comes with a power supply, or a drive enclosure (those are even quite beefy ones!). Competing products like the ECS Liva come with their own power supplies too, and the total cost of the system is the same as the Pi.

> They say to use a charger that's rated for at least 2.5A. That does not include most crappy phone chargers.

They've backpedaled on this since the launch after problems started appearing. The official spec at launch was that the Pi pulled 700ma for Model B and 300ma for Model A, and pretty much any random charger meets that spec. Anyway, most chargers are significantly overstating the amount of clean power they can provide, because they expect the phone to be using them for charging, not for operating.

You can see the original statement from the Pi Foundation here: https://www.raspberrypi.org/blog/power-supply-confirmed-as-5...

And then after launch they started realizing they had problems: https://www.raspberrypi.org/forums/viewtopic.php?f=2&t=5420

> I'll be testing PSUs soon as well, although maybe not as thoroughly. It certainly seems that the Foundation may have been wrong in assuming that USB chargers produce the current they say they do and that all USB cables are reasonably constructed.

The fact that $1.99 adapters you get off eBay were built like shit wasn't a shocker to anyone, even at the time. That's a hilariously naieve assumption for them to make.

> They also sell an official RPi power supply which anyone is free to buy if they're concerned about this issue.

This only launched within the last year. Good on them for finally doing it, but it should be included with the device, and should have been included from day 1.

http://www.electronicspecifier.com/power/stontronics-manufac...