What ultimately killed AirPower
Quite unexpectedly, Apple canceled the long-awaited AirPower wireless charging pad. The company says that the product could not reach its “high standards", but does not specify for what reason. We closely followed this issue and can express a hunch supported by facts on this subject.
AirPower was first introduced to the public in September 2017 during the presentation of the iPhone X. The company promised a single stand for wireless charging that can charge three devices at once - for example, the iPhone, Apple Watch and AirPods (headphones have only recently acquired wireless charging).
Apple planned to release AirPower a year after the iPhone X, in 2018. However, at some point, there were reports of many different delays . The year 2018 was on, rumors about the cancellation of the project grew, especially after Apple completely removed from its site all references to this product a year after its announcement.
Since 2019, however, there has been a glimmer of hope: there have been rumors that AirPower production is being established, and that it is possible to bring this device closer to the exit stage. Moreover, it came so close that in the beta version of iOS 12.2 - released just 10 days before the cancellation of AirPower - there was official support for the now canceled device. And the second generation AirPods on the back of the box even havePhoto of charging cradle.
AirPower was canceled in just nine days, which made us think about what could happen. After all, the market already has a sufficient number of wireless chargers that can simultaneously charge several devices. However, unlike existing mats (which are just three separate chargers arranged in a row in a single enclosure), Apple wanted to take this technology to the next level.
Given all this, we have a theory about why Apple’s wireless charging completely failed, and why it happened at the last moment.
Overheating and interference
Wireless charging uses electromagnetic induction to charge the phone. Coils from wires are built into the phone and charging: charging takes current from the outlet, drives it through the coil, and creates an electromagnetic field. This field induces an electric current in the coil of the phone, which it uses to charge the battery.
However, not quite clean and perfect electricity is transferred to the phone. It makes noise that may interfere with other wireless devices. Therefore, the U.S. Federal Communications Commission and regulators in other countries set strict limits on wireless emissions.
Noise from one coil may not be a problem, but each coil produces a slightly different electromagnetic wave. When superimposed, their interference amplifies these waves. Just as ocean waves in a collision combine altitude, so radio waves can combine intensity in interaction.
It is extremely difficult to control these overlapping harmonic frequencies , and the more coils you try to integrate, the more difficult it is to do. Judging by the patent, Apple had an ambitious plan to use much more coils than other charges on the market.
According to rumors, Apple was considering a variant with the number of coils up to 32 - 16 pieces are shown in the figure for the patent.
Other mats for wireless charging of several devices have two or three coils in a row, but you need to poke your phone a bit to find the right place above one of the coils and start charging. In its AirPower, Apple tried to create one large charging surface using overlapping coils, which would allow charging several devices lying anywhere on the mat. However, several difficulties arise.
We asked an engineer with experience in creating wireless charging systems, overcoming which obstacles Apple worked on. “Over time, these harmonics add up and very powerful signals appear in the air,” explains William Lampkins, Technical Vice President, O & S Services. - And this can be difficult - for example, such radiation can stop someone's pacemaker, if it is powerful enough. Or close someone’s hearing aid. ” If harmonics scattered from the Apple device in all directions, AirPower might not be able to pass the tests of US or EU regulators.
Part of the surprise of canceling AirPower is how suddenly and at the last minute it all happened, right in the wake of AirPods 2. However, Lampkin says this sometimes happens. He suggested that Apple managed to get AirPower to work in the lab: “Well, that’s how it all happens when you can get the device to work first. Nobody pays attention to electromagnetic interference to the very end. " rulesCommunication fees for wireless charging are very strict, and limit the radiation power to 20 cm from the device to 50 mW / cm 2 .
For several months, we heard rumors about problems with the overheating of AirPower, and this fits perfectly into our theory. To power multiple devices with a large array of coils would require a lot of energy. “Overheating means too much current in the coils, which means they are trying to increase the energy level,” says Lampkins. “I suppose that they are trying too hard to pump up the power of the field, as a result of which the device overheats.”
Apple has driven itself into an electromagnetic angle. They wanted to do something that was physically possible - and it worked for them in the laboratory - but they could not fit into the implacable requirements for the transmission of electromagnetic waves, designed in such a way as to protect us from our gadgets.