Patent attributes
A wireless power transmission system includes a wireless power transmitter, a wireless power transfer circuit electrically connectable to the at least one wireless power transmitter, and a transmitter controller. The transmitter controller is configured to perform an initial foreign object detection prior to any transmission of wireless power, the initial foreign object detection for detecting presence of a foreign object within a charge volume, the initial foreign object detection determining an initial quality factor (Q). The controller is further configured to begin wireless power transfer negotiations with one of the one or more wireless power receivers, if the initial Q has a value in a range indicating that an object in the charge volume is a wireless power receiver, and perform continuous foreign object detection, if the initial Q has the value in the range indicating that an object in the charge volume is a wireless power receiver.
