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US 9,178,361 B2Granted
Methods and systems for detecting foreign objects in a wireless charging system
AssigneeConvenientPower, Ltd.
InventorsXun Liu, Laurens Henricus Swaans, Ka Wai Paul Chan, Ho Kan Low, Wing Kwong Chan
Life of this patent
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Abstract
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.
Claims21
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;
- at least one foreign object detection (FOD) coil located proximate to the power transmitter coil and oriented to detect foreign objects that disturb the power transmission, the FOD coil characterized by a FOD coil dimension that is a lateral dimension of the FOD coil and that is smaller than the lateral dimension of the power transmitter coil, wherein the at least one FOD coil comprises two or more FOD coils, the at least one power transmitter coil comprises two or more power transmitter coils;
- and
- a controller configured to select power transmitter coils for activation based on which FOD coils have detected foreign objects.
1 more element
Dependencies are inferred from the claim text.