Abstract: A power-transmitter-unit comprises a power-transmitting-coil and a resonant-capacitor that define an LC circuit. A controller defines a power-transmission-mode of operation and a foreign-object-detection-mode of operation. In the power-transmission-mode of operation: a power-stage provides a potential-difference across a first-end and a second-end of the LC circuit. In the foreign-object-detection-mode of operation: for a recuperation-time-interval, the power-stage provides a potential-difference across the first-end and the second-end of the LC circuit that has the opposite polarity to the current through the power-transmitting-coil; after expiry of the recuperation-time-interval, the first-end of the LC circuit is connected to the second-end of the LC circuit such that the LC circuit is short-circuited and defines a closed-LC-circuit; and the controller receives measured-signalling that is representative of an operating parameter of the power-transmitter-unit.

Abstract: A power-transmitter-unit includes a power-transmitting-coil for wirelessly providing power to a power-receiver-unit, and a resonant-capacitor connected to the power-transmitting-coil, such that together they define an LC circuit. The LC circuit includes a first-end and a second-end. A controller defines a foreign-object-detection-mode of operation, wherein, in the foreign-object-detection-mode of operation, the first-end of the LC circuit is connected to the second-end of the LC circuit such that the LC circuit is short-circuited and defines a closed-LC-circuit, and the controller is configured to receive a coil-current-signal that is representative of the current through the closed-LC-circuit.

Abstract: Foreign object detection (FOD) is provided for wireless energy transfer systems. A transmitter receives an input voltage, converts it to an output current, supplies the output current to a transmit coil, and samples a first set of analog signals to generate a first set of digital values. A receiver converts a current induced in a receive coil by energy transferred from the transmit coil into an output voltage, samples a second set of analog signals to generate a second set of digital values, and communicates the second set of digital values to the transmitter. The transmitter generates a FOD signal based upon the first and second sets of digital values that indicates detection or non-detection of a foreign object within the energy transfer. In further embodiments, a comparison of the detected power loss or efficiency to expected power loss or efficiency is used to generate the FOD signal.

Abstract: A power-transmitter-unit comprises a power-transmitting-coil and a resonant-capacitor that define an LC circuit. A controller defines a power-transmission-mode of operation and a foreign-object-detection-mode of operation. In the power-transmission-mode of operation: a power-stage provides a potential-difference across a first-end and a second-end of the LC circuit. In the foreign-object-detection-mode of operation: for a recuperation-time-interval, the power-stage provides a potential-difference across the first-end and the second-end of the LC circuit that has the opposite polarity to the current through the power-transmitting-coil; after expiry of the recuperation-time-interval, the first-end of the LC circuit is connected to the second-end of the LC circuit such that the LC circuit is short-circuited and defines a closed-LC-circuit; and the controller receives measured-signalling that is representative of an operating parameter of the power-transmitter-unit.

Abstract: A power-transmitter-unit includes a power-transmitting-coil for wirelessly providing power to a power-receiver-unit, and a resonant-capacitor connected to the power-transmitting-coil, such that together they define an LC circuit. The LC circuit includes a first-end and a second-end. A controller defines a foreign-object-detection-mode of operation, wherein, in the foreign-object-detection-mode of operation, the first-end of the LC circuit is connected to the second-end of the LC circuit such that the LC circuit is short-circuited and defines a closed-LC-circuit, and the controller is configured to receive a coil-current-signal that is representative of the current through the closed-LC-circuit.

Abstract: Foreign object detection (FOD) is provided for wireless energy transfer systems. A transmitter receives an input voltage, converts it to an output current, supplies the output current to a transmit coil, and samples a first set of analog signals to generate a first set of digital values. A receiver converts a current induced in a receive coil by energy transferred from the transmit coil into an output voltage, samples a second set of analog signals to generate a second set of digital values, and communicates the second set of digital values to the transmitter. The transmitter generates a FOD signal based upon the first and second sets of digital values that indicates detection or non-detection of a foreign object within the energy transfer. In further embodiments, a comparison of the detected power loss or efficiency to expected power loss or efficiency is used to generate the FOD signal.