Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

What Finally Killed AirPower

ifixit.org

Post reply on HN
Print view View original

91–100 of 280 posts

Re: What Finally Killed AirPower

#91

Post by cybersol »

TTPrograms wrote: post #63
hn_throwaway_99 wrote: post #9

Earlier quoted context omitted.

I'm quite sure they didn't "wait until the end" to do the testing. First, this article is iFixit's speculation. Second, they probably did something similar to what iFixit envisioned: they did test early and knew it didn't pass muster, but thought they could eventually engineer themselves a fix, until they finally just hit a brick wall (aka physics) and found it wasn't an issue they could overcome.

A good engineer hits the "physics limit" brick wall pretty early in the design process... I would think it more likely that they thought they could change FCC regulation via lobbying efforts in time for release.

[flagged]

Re: What Finally Killed AirPower

#92

Post by Fezzik »

brian-armstrong wrote: post #11

So my phone is charged by a cable. It plugs into the wall on one side and then plugs into my phone on the other. This system works great - I plug my phone in when I go to bed and unplug it when I wake up. The cable is long enough to plug into my phone even if I want to use it in bed. It's easy, cheap and failproof. What is the draw of wireless charging? What is it that I'm missing? Did anyone ask for this?

Cables are not entirely fail-proof - I imagine many people here, including myself, have seen smoldering Apple branded mag-safe, 30 pin, and lightning cables. Moving energy from one place to another, quickly and efficiently, at the small-scale of modern electronics, is tough. I prefer cables for charging, too, but as others have posted wiredless-ness sure is convenient, a la AirPods. I swore by wired headphones until I got AirPods - now I never yank my EarPods out of my ear while cooking or if my dogs jump on me while I am on the phone (for example; small conveniences).

Re: What Finally Killed AirPower

#93

Post by isoskeles »

quotemstr wrote: post #36

> The FCC rules for wireless charging devices like AirPower are quite strict, and limit exposure to 20 cm (8 in) above the device to 50 mW/cm^2. Who's to say that 50 mW/cm^2 is the right field strength limit? Remember when we couldn't use cell phones on airplanes during takeoff because of the theoretical possibility that something, somewhere might interfere? As it turns out, there was no interference problem, cell ph…

I want to give you the benefit of the doubt here, in what way did the ban on cellphones on planes stall progress? It seemed more like a minor annoyance / inconvenience, but I could be misunderstanding or not have context.

Re: What Finally Killed AirPower

#94

Post by the_pwner224 »

pg_bot wrote: post #74

Could you put a pressure sensor on the pad and only power on the coils directly underneath the object? I assume with software you could selectively turn on/off areas of the mat to manage the heat problems that come with multiple coils being on at once. I could see it being a problem if they were charging all at the same time but you should be able to fake it and call that good enough. All the devices have to charge,…

There wouldn't be any need for pressure sensors; this already happens. The charged device adds some power to its own coil and the charging station detects that (it's unidirectional communication). For example my charging station lights up about a second after putting my phone down, and can show the battery status with the light. I would assume that when there's nothing on them the coils transmit in a low-power mode, with the protocol allowing the device to ask for more/less power as required (edit: Wikipedia confirms that the device can actually send some pretty precise instructions to the station, with voltage controllable in 50 mV increments [0]).

So logically it would seem the heat issue happens when there are three coils active at the same time transmitting at high power - the peak heat output is the issue.

[0]: https://en.wikipedia.org/wiki/Qi_(standard)

Re: What Finally Killed AirPower

#95

Post by etatoby »

skellera wrote: post #73
_bxg1 wrote: post #53

Earlier quoted context omitted.

It takes something easy and makes it effortless . Like AirPods, this has a surprising number of implications that you really don't think about until you try it. If I'm just setting my phone down on my desk and it's at 50%, and my cable is right there, I may not bother to plug it in. Especially if I might get up again in 5 or 10 minutes. But if I can just set it down in a particular place and regain a couple percentag…

Does that have an effect on battery life though? Constant micro charges?

It should have a positive effect, because you're avoiding larger charges and keeping your battery at optimal levels.

Re: What Finally Killed AirPower

#96

Post by stock_toaster »

david-s wrote: post #3
clay_the_ripper wrote: post #2

What a shame, this would be the actual experience of wireless charging that I had envisioned it was. The reality of wireless charging is quite different: fiddly and possible to have your phone be dead in the morning. I wish someone could figure out how to make a true wireless charging mat like this. As it stands, I wouldn’t buy a wireless charger for my wife for example. She’ll just plonk it on there and then ask me…

I've had really good luck with the tilted stand ones. If my phone is propped up on it, it's charging. I have had much worse luck with the lay-down pad ones.

Same. I have an anker stand and it works great.

Re: What Finally Killed AirPower

#97

Post by sowbug »

Drdrdrq wrote: post #78
cannonedhamster wrote: post #50

Earlier quoted context omitted.

That's why we have to bend them so often in real life with tricks. In media they can just make something up, we've got to find real solutions. I'm sure that one exists but it's either too expensive currently or not consistent enough yet. Yet being the key word there. I'm sure this will be an elegantly solved issue at some point, just might require some more smarts on the hardware side.

For example detecting where the device is and adjusting the current in separate coils accordingly? I don't buy the explanation that this is about interferences. It doesn't seem like an insurmountable problem to me.

C(32, 3) is 4960. That means almost 5,000 different interference patterns to deal with. Since every manufactured device will vary (since each of its 32 manufactured coils will differ slightly from the next), that's 5,000 calibrations that need to be done on every single manufactured device. And that's best case, assuming (for example) that calibration is a single metric per coil over time.

Re: What Finally Killed AirPower

#98

Post by bestnameever »

etatoby wrote: post #95
skellera wrote: post #73

Earlier quoted context omitted.

Does that have an effect on battery life though? Constant micro charges?

It should have a positive effect, because you're avoiding larger charges and keeping your battery at optimal levels.

i've found what I believe to be the heat generated by wireless chargers to have a negative effect on my battery longevity. Personally, I avoid them now after being a huge advocate from them. The reality is, Battery life on phones have improved to the point that I also rarely need to charge my phone anymore other than what I'm about to go to sleep anyway.

Re: What Finally Killed AirPower

#99

Post by sowbug »

brian-armstrong wrote: post #11

So my phone is charged by a cable. It plugs into the wall on one side and then plugs into my phone on the other. This system works great - I plug my phone in when I go to bed and unplug it when I wake up. The cable is long enough to plug into my phone even if I want to use it in bed. It's easy, cheap and failproof. What is the draw of wireless charging? What is it that I'm missing? Did anyone ask for this?

One hand vs. two. Never have to look for the cable that fell behind the nightstand. Picking up the phone at night doesn't risk yanking something else off the nightstand with the cable.

Re: What Finally Killed AirPower

#100

Post by stouset »

kitotik wrote: post #10
ReverseCold wrote: post #7

Earlier quoted context omitted.

If a human can mess it up, they will mess it up. (Modification of Murphy's Law.)

When compared to plugging into a grounded AC wall socket or even a standard USB port, I find positioning an iphone on a wireless charger far easier.

It’s not about how easy it is to do right. It’s about how easy it is to do it wrong and not notice.

And even if you are right, it’s moot if it’s on a nightstand and your cat bumps it in the middle of the night.

Post reply on HN