METHODS AND SYSTEMS FOR DETECTING FOREIGN OBJECTS IN A WIRELESS CHARGING SYSTEM

摘要

Methods and systems are described for using detection coils to detect metallic or conductive foreign objects that can interfere with the wireless transfer of power from a power transmitter to a power receiver. In particular, the detection coils are targeted to foreign objects that are smaller than a power transmitter coil in the power transmitter.

主权项

1. A wireless power charging system for charging a separate device having a power receiver coil, the wireless power charging system comprising:
at least one power transmitter coil configured for transmitting power by inductive coupling to the power receiver coil in the separate device, the power transmitter coil characterized by a transmitter coil dimension that is a lateral dimension of the power transmitter coil; and at least one foreign object detection (FOD) coil positioned in a location where a field transmitted by the power transmitter coil is the strongest, the FOD coil characterized by a FOD coil dimension that is the lateral dimension of the FOD coil and that is smaller than the transmitter coil dimension.