Stryker Corporation
Foreign Object Detection For Wireless Charging Systems

Abstract:

Wireless charging systems and methods for detecting foreign objects proximate the wireless charging systems. A wireless charging system (10) includes a wirelessly chargeable battery (14) that receives power from a wireless charging device (16) when the wirelessly chargeable battery (14) is proximate the wireless charging device (16). The wireless charging device (16) determines an actual electrical consumption of the wireless charging system (10), and the wirelessly charging battery (14) measures a voltage induced in the wirelessly chargeable battery (14) by the wireless charging device (16). The wireless charging device (16), the wirelessly chargeable battery (14), or a combination of the two determines an expected electrical consumption of the wireless charging system (10) based on the measured voltage, and determines whether a foreign object (12) is proximate the wireless charging system (10) based on the expected and actual electrical consumptions.