Out of the blue Apple the long awaited AirPower wireless charging mat. The company says the product failed to meet its "high standards" but did not elaborate on why. We have been following this issue closely and can offer a factual guess on this matter.
AirPower was first introduced to the public in during the presentation of the iPhone X. The company promised a single wireless charging stand that can charge three devices at the same time - for example, iPhone, Apple Watch and AirPods (headphones wireless charging capability).
Apple planned to release AirPower a year after the iPhone X, in 2018. However, at some point there were reports of . As 2018 rolled on, rumors of the project's cancellation grew, especially after Apple all references to this product from its website a year after its announcement.
Since 2019, however, there has been a glimmer of hope: that the production of AirPower is being established, and that there is a possibility of approaching this device to the exit stage. And it came so close that iOS 12.2 beta β released just 10 days before AirPower was canceled β now canceled device. And second-generation AirPods even have charging stand.
AirPower was canceled after only nine days, which left us wondering what could have happened. After all, there are already a sufficient number of wireless chargers on the market that can simultaneously charge several devices. However, unlike existing mats (which are just three separate chargers lined up in a single case), Apple wanted to take this technology to the next level.
Given all this, we have a theory about why Apple's wireless charging has completely failed, and why it happened at the last moment.
Overheating and interference
Wireless chargers use electromagnetic induction to charge your phone. Coils of wires are built into the phone and into the charger: the charger takes current from the socket, drives it through the coil, and creates an electromagnetic field. This field induces an electric current in the phone's coil, which it uses to charge the battery.
However, not quite clean and ideal electricity is transmitted to the phone. It produces noise that can interfere with other wireless devices. Therefore, the US Federal Communications Commission and regulators in other countries impose strict limits on wireless exposure.
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 combine height when they collide, so radio waves can combine intensity when they interact.
Manage these overlaps extremely complex, and the more coils you try to integrate, the harder it gets. According to the patent, Apple had an ambitious plan to use many more coils than other chargers on the market.
According to rumors, Apple was considering an option with the number of coils up to 32 - the drawing for the patent shows 15 pieces.
Other wireless multi-device charging mats have two or three coils in a row, but you have to fiddle around with your phone a bit to find the right spot above one of the coils and start charging. With AirPower, Apple tried to create one large charging surface using overlapping coils, which would allow multiple devices to be charged anywhere on the mat. However, this raises several difficulties.
We asked an engineer with experience building wireless charging systems what obstacles Apple was working to overcome. βOver time, these harmonics add up and create very strong signals in the air,β explains William Lumpkins, technical vice president . βAnd that can be trickyβfor example, that kind of radiation could stop someone's pacemaker, if it's powerful enough. Or block someone's hearing aid." If the harmonics were flying in all directions from the Apple device, AirPower may not have been able to pass the tests of US or EU regulators.
Part of the surprise of AirPower's cancellation is how sudden and last-minute it all happened, right on the heels of the AirPods 2 release. Lumpkin says that happens sometimes, though. He suggested that Apple managed to get AirPower to work in the lab: βWell, thatβs how it happens when you manage to get the device to work first. No one pays attention to electromagnetic interference until the very end.β Communication fees for wireless charging are quite strict, and 20 cm from the device at 50 mW/cm2.
Several months have reached us about problems with AirPower overheating, and this perfectly fits into our theory. To power several devices with a large array of coils would require a lot of energy. βOverheating means too much current in the coils, which means they are trying to increase the energy level,β Lumpkins says. βMy guess is that they are trying to pump the power of the field too much, causing the device to overheat.β
Apple has driven itself into an electromagnetic corner. They wanted to make something that was physically possible - and it worked for them in the lab - but they couldn't fit into the unforgiving demands of electromagnetic wave transmission designed to keep us safe from our gadgets.
Source: habr.com