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Why Apple Won't Adopt a Wireless Charging Standard
Lucas123 writes As the battle for mobile dominance continues among three wireless charging standards, with many smartphone and wearable makers having already chosen sides, Apple continues to sit on the sideline. While the new Apple Watch uses a tightly coupled magnetic inductive wireless charging technology, it still requires a cable. The only advantage is that no port is required, allowing the watch case to remain sealed and water resistant. The iPhone 6 and 6 Plus, however, remain without any form of wireless charging, either tightly coupled inductive or more loosely coupled resonant charging. Over the past few years, Apple has filed patents on its own flavor of wireless charging, a "near field" or resonant technology, but no products have as yet come to market. If and when it does select a technology, it will likely be its own proprietary specification, which ensures accessory makers will have to pay royalties to use it.
Real Nerds know that you need AC for wireless charging, DC just won't cut it.
Seriously though, my opinion as a physicist/engineer is that wireless charging is a little dumb. It wastes a lot of power in an age where energy conservation is paramount, for what exactly? It's not like you can charge your phone from a distance. Inductive charging is a sensible tradeoff in things like dil^Welectric toothbrushes -- just because it can be done, doesn't mean it's great for everything.
As a practical matter, the efficiencies are affected by the frequency of the AC Signal. At 50/60 Hz, there are significant losses to heat, due to poor power-factor numbers as well as problems with core saturation (esp. At 50 Hz). However, if you crank the frequency up to about 100 kHz, like a lot of SMPS designs, things begin to look a lot better. Crank it up again, to a few MHz, and the efficiencies get really good, and the components get pretty damned small.
But, as a "physicist/engineer" (which no one who was really either of those would call themselves), you should already know all this.
And beside all that, the measly few Watts that are needed to charge a phone in a reasonable period of time aren't going to deplete the planet's energy reserves anytime soon. Even a poor transformer operating in the 60 Hz world typically achieves over 80% efficiency in it's energy transfer from Primary to Secondary. So, extrapolating from the real-world example of the original 10W iPhone "cube" charger, you would only have to increase that to around 12W to overcome the 20% loss from a small air-gap.
I am NOT talking about charging-at-a-distance. The inverse-square law gets you pretty quick when doing that!
It bugged me when Apple dropped USB cable syn(hronization) feature in Mac OS X 10.9. Lots of iDevice users were angry and made Apple add it back in the later versions.
Something that never happened bugged you? Apple never removed cable syncing from Mac OS X and iOS devices.
What did change, in Mavericks, was that SyncServices was removed. SyncServices was only responsible for syncing calendars and contact information and without it iCloud was required to sync calendars and contacts. iTunes still synced everything else.
SyncServices was added back in Mac OS X 10.9.3. But at no time did they remove the ability to sync music, photos, videos, apps, or anything other than contacts and calendars from iTunes.