Apple may have canceled plans for its AirPower wireless charger, but the company is apparently still interested in such technology as evidenced by a newly granted patent (number 10,511,197) for a “wireless charging system with object detection.”
AirPower was originally announced in September 2017 alongside the iPhone X. It was supposed to be able to charge a Qi-compatible iPhone, an Apple Watch, and a pair of AirPods (in a special wireless charging case) at the same time regardless of where they were placed on the pad. However, there was constant rumors of production, engineering, and manufacturing difficulties. Apple’s new patent involves systems and methods for inductive power transfer for consumer electronic devices.
Apple’s new patent filing is for a wireless charging system with a wireless power transmitting device such as a device with a charging surface that wirelessly transmits power to a portable electronic device. The portable electronic device receives the wirelessly transmitted power and uses this power to charge an internal battery or to power the device.
Here’s the summary of the invention: “A wireless power transmitting device transmits wireless power signals to a wireless power receiving device. The wireless power receiving device has a wireless power receiving coil in a resonant circuit that resonates at a wireless power receiving circuit resonant frequency. The wireless power transmitting device has coils. The coils are supplied with a drive signal in bursts to detect external objects.
“Measurement circuitry includes an oscillator for supplying the drive signals and a peak detector and analog-to-digital converter for gathering measurements on the coils to which the drive signals have been supplied. Rate-based-filtering is applied to output signals from the analog-to-digital converter to distinguish between temperature drift effects and object placement effects. The frequency of the drive signals is slightly greater than the wireless power receiving circuit resonant frequency.”