Apple may have abandoned (for now) its plans for an AirPower charging system, but the company is still investigating wireless charging system and has applied for a patent (number 20200153278) for a “transmitter in an inductive power transfer system.”
In the patent filing, Apple says inductive power transfer (IPT) systems are a well known area of established technology used in, for example, wireless charging of electric toothbrushes) and developing technology (such as wireless charging of handheld devices on a `charging mat`). Typically, a primary side generates a time-varying magnetic field from a transmitting coil or coils.
This magnetic field induces an alternating current in a suitable receiving coil that can then be used to charge a battery, or power a device or other load. Apple says there are issued with current (no pun intended) systems and is looking to “provide a transmitter that produces a magnetic field with improved power transfer characteristics, or to at least provide the public with a useful choice.
Here’s the summary of the patent filing: “An inductive power transfer transmitter that includes an enclosure for accommodating devices to be energised. The enclosure has one or more side walls and one or more coils for generating an alternating magnetic field within the enclosure. The density of the one or more coils varies with distance from an end of the one or more sidewalls. There is also disclosed an inductive power transmitter that includes one or more magnetically permeable layers wherein the combined thickness or the permeability of the one or more magnetically permeable layers varies.”
