Abstract: A power transfer device is a power transmitter (201) or a power receiver (205) conducting power transfer using an electromagnetic power transfer signal employing a repeating time frame comprising a power transfer time interval and an object detection time interval. A power transfer circuit (303, 307) comprises a power transfer coil (203, 207) receiving or generating the power transfer signal during the power transfer time intervals. A communicator (315, 323) communicates with the other device via an electromagnetic communication signal. A communication resonance circuit (317, 321) comprises a communication antenna (319, 325) for transmitting or receiving the electromagnetic communication signal. During the communication, the communication resonance circuit (317, 321) provides a resonance at a first resonance frequency to the communicator (315, 323).

Abstract: A power transmitter (101) comprises a driver (201) generating a drive signal for a transmitter coil to generate a power transfer signal during a power transfer time interval and an electromagnetic test signal during a foreign object detection time interval. A set of balanced detection coils (207, 209) comprise two detection coils arranged such that signals induced in the two detection coils by an electromagnetic field generated by the transmitter coil compensate each other. A foreign object detector (205) is coupled to the detection coils and performs foreign object detection during the foreign object detection time interval. The foreign object detector (205) is arranged to detect a foreign object in response to a property of a signal from the detection coils meeting a foreign object detection criterion.

Abstract: A power transfer apparatus being a power transmitter (101) or power receiver (103) of a power transfer via a power transfer signal comprises a power coil (103, 107) for transferring power with a complementary power transfer coil (107, 103) being the other apparatus of the power transfer operation. A first communicator (205, 305) communicates data with the complementary power transfer apparatus using modulation of the power transfer signal. A second communicator (207, 307) communicates power transfer control data via a second communication channel that is independent of the power transfer signal and has a communication data rate at least ten times higher.

Abstract: A power transmitter (101) comprises a driver (201) generating a drive signal for an output resonance circuit comprising transmitter coil (103) generating a power transfer signal. A resonance detector (307) determines a coupled resonance frequency for the output resonance circuit during where the coupled resonance frequency is a resonance frequency for the output resonance circuit for the transmitter coil (103) being coupled to a receiver coil (107) which is part of a power transfer input resonance circuit of the power receiver (105). The input resonance circuit has a quality factor of no less than ten. An estimation circuit (309) determines a coupling factor estimate for the coupling between the transmitter coil (103) and the receiver coil (107) in response to a non-coupled resonance frequency of the output resonance circuit and the first effective resonance frequency. An adapter (311) sets an operating parameter in response to the coupling factor estimate.

Abstract: A power transmitter (101) comprises a driver (201) generating a drive signal for a transmitter coil to generate a power transfer signal during a power transfer time interval and an electromagnetic test signal during a measurement time interval. A set of balanced detection coils (207, 209) comprise two detection coils arranged such that signals induced in the two detection coils by an electromagnetic field generated by the transmitter coil compensate each other. An estimation circuit (205) determines a position/coupling factor estimate for the power receiver (105) in response to signals from the plurality of sets of balanced detection coils (207, 209) during the at least one measurement time interval.

Abstract: A power transmitter (101) comprises a driver (201) generating a drive signal for a transmitter coil to generate a power transfer signal during a power transfer time interval and an electromagnetic test signal during a foreign object detection time interval. A set of balanced detection coils (207, 209) comprise two detection coils arranged such that signals induced in the two detection coils by an electromagnetic field generated by the transmitter coil compensate each other. A foreign object detector (205) is coupled to the detection coils and performs foreign object detection during the foreign object detection time interval. The foreign object detector (205) is arranged to detect a foreign object in response to a foreign object detection criterion requiring that at least one signal from a set of balanced detection coils (207, 209) exceeds a first threshold and not more than a given threshold number of at least two of the signals exceed a second threshold.

Abstract: A power transfer device is a power transmitter (201) or a power receiver (205) conducting power transfer using an electromagnetic power transfer signal employing a repeating time frame comprising a power transfer time interval and an object detection time interval. A power transfer circuit (303, 307) comprises a power transfer coil (203, 207) receiving or generating the power transfer signal during the power transfer time intervals. A communicator (315, 323) communicates with the other device via an electromagnetic communication signal. A communication resonance circuit (317, 321) comprises a communication antenna (319, 325) for transmitting or receiving the electromagnetic communication signal. During the communication, the communication resonance circuit (317, 321) provides a resonance at a first resonance frequency to the communicator (315, 323).

Abstract: A power transfer device is a power transmitter (201) or a power receiver (205) conducting power transfer using an electromagnetic power transfer signal employing a repeating time frame comprising a power transfer time interval and an object detection time interval. A power transfer circuit (303, 307) comprises a power transfer coil (203, 207) receiving or generating the power transfer signal during the power transfer time intervals. A communicator (315, 323) communicates with the other device via an electromagnetic communication signal. A communication resonance circuit (317, 321) comprises a communication antenna (319, 325) for transmitting or receiving the electromagnetic communication signal. During the communication, the communication resonance circuit (317, 321) provides a resonance at a first resonance frequency to the communicator (315, 323).

Abstract: A power receiver receives a wireless power transfer from a power transfer signal generated by a wireless power transmitter during a power transfer phase. The power transfer signal employing a repeating time frame during the power transfer phase where the frame comprises at least a power transfer time interval and a foreign object detection time interval. The power receiver comprises a synchronizer (311) which synchronizes a local time reference to the repeating time frame and a load controller (309) which disconnects a load (303) during at least part of the foreign object time detection time intervals during at least part of the power transfer phase. The timing of the disconnecting is dependent on the local time reference. A mode controller (313) switches between a first operational mode and a second operational mode for the power transfer time intervals in response to a reliability measure for the synchronization.

Abstract: A power transmitter (101) comprises a driver (201) generating a drive signal for a transmitter coil to generate a power transfer signal during a power transfer time interval and an electromagnetic test signal during a foreign object detection time interval. A set of balanced detection coils (207, 209) comprise two detection coils arranged such that signals induced in the two detection coils by an electromagnetic field generated by the transmitter coil compensate each other. A foreign object detector (205) is coupled to the detection coils and performs foreign object detection during the foreign object detection time interval. The foreign object detector (205) is arranged to detect a foreign object in response to a property of a signal from the detection coils meeting a foreign object detection criterion.

Abstract: There is provided a wireless power transfer system comprising a power transmitter for providing power to a power receiver via an inductive power signal which comprises a power transmitter which in turn comprises a transmitter resonant circuit comprising a power transmitting inductor having a transmission resonance at a first frequency and arranged for generating the power transfer signal, the power transmitting inductor being arranged to be magnetically couplable to a power receiver inductor in the power receiver, a power transmitter driver, operably coupled to the power transmitter resonant circuit and arranged to generate a drive signal for the power transmitting inductor, a transmitter communication resonant circuit, different from the transmitter resonant circuit and directly or capacitively coupled to the power transmitting inductor, being arranged to establish a transmitter communication resonance at a second frequency, different from the first frequency, for communications, wherein the power transmitti

Abstract: A wireless power receiver, method, and corresponding processing circuitry for the same are disclosed. The wireless power receiver includes a receiver coil configured to receive a wireless power transfer signal transmitted by a wireless power transmitter and a load coupled to the receiver coil. The wireless power receiver further includes communication circuitry configured to communicate a synchronization message to the wireless power transmitter which indicates time durations for repeating time intervals of foreign object detection and wireless power transfer. The foreign objection detection time periods correspond to periods of reduced power transfer to improve detection of foreign objects.

Abstract: An intermediate device for supporting a power transfer to an electromagnetic load (505) from a power transmitter (201) providing a power transfer electromagnetic signal comprises a resonance circuit (507) that includes a coil (701) and a capacitor (703). The coil (701) is arranged to electromagnetically couple to the power transmitter (201) and to the electromagnetic load (505) such that energy of the power transfer electromagnetic signal from the power transmitter (201) is concentrated towards the electromagnetic load (505). A hollow support structure (1001) has a laterally positioned air inlet (1205) and a centrally positioned air outlet (1207). The coil (701) is mounted on the hollow support structure (1001) and disposed around the central air outlet (1207). The device further comprises an air flow generator (901) for creating a flow of air into the air inlet (1205).

Abstract: A power transmitter (101) for a wireless power transfer system comprises a transmitter coil (103) and a driver (201) generates a drive signal) for the transmitter coil (103) employing a repeating time frame with a power transfer time interval and a reduced power time interval during which a power level of the power transfer signal is reduced. A driver (201) generates a drive signal for the transmitter coil (103) to generate the power transfer signal. A communicator (205) receives messages from the power receiver (105) and an adapter (213) adapts a timing property of the reduced power time interval in response to at least a first message received from the power receiver (105). A synchronizer (206) for synchronizing a foreign object detection and the generation of a test signal to occur during the reduced power time interval. The operation may typically be a foreign object detection or communication, and the timing property may e.g. be a duration of the reduced power time interval.

Abstract: A power transfer apparatus being a power transmitter (101) or power receiver (103) of a power transfer via a power transfer signal comprises a power coil (103, 107) for transferring power with a complementary power transfer coil (107, 103) being the other apparatus of the power transfer operation. A first communicator (205, 305) communicates data with the complementary power transfer apparatus using modulation of the power transfer signal. A second communicator (207, 307) communicates power transfer control data via a second communication channel that is independent of the power transfer signal and has a communication data rate at least ten times higher.

Abstract: A power transmitter (101) for a wireless power transfer system comprises a transmitter coil (103) and a driver (201) generates a drive signal for the transmitter coil (103) employing a repeating time frame with a power transfer time interval and a foreign object detection time interval. A test generator (211) generates a test drive signal for a test coil (209) during the foreign object detection time interval. A foreign object detector (207) performs a foreign object detection test based on a measured parameter for the test drive signal. Prior to entering a power transfer phase, an adapter (213) controls the power transmitter (101) to operate in a foreign object detection initialization mode in which a preferred value of a signal parameter for the test drive signal is determined in response to at least a first message received from the power receiver (105). During the foreign object detection time interval the signal parameter of is set to the preferred value.

Abstract: A wireless power transfer system includes a power receiver (105) receiving a power transfer from a power transmitter (101) via a wireless inductive power transfer signal. The power transmitter (101) comprises a transmit power coil (103) generating the power transfer signal. A test signal coil (209) coupled to a test signal generator (211) generates a magnetic test signal. A plurality of spatially distributed detection coils (213) is coupled to measurement unit (215) generating a set of measurement values reflecting signals induced in the detection coils (213) by the magnetic test signal. A processor (217) determines a measurement spatial distribution of the measurement value where the spatial distribution reflects positions of the detection coils (213). A foreign object detector (219) detects a presence of a foreign object in response to a comparison of the measurement spatial distribution to a reference spatial distribution.

Abstract: A power receiver receives a wireless power transfer from a power transfer signal generated by a wireless power transmitter during a power transfer phase. The power transfer signal employing a repeating time frame during the power transfer phase where the frame comprises at least a power transfer time interval and a foreign object detection time interval. The power receiver comprises a synchronizer (311) which synchronizes a local time reference to the repeating time frame and a load controller (309) which disconnects a load (303) during at least part of the foreign object time detection time intervals during at least part of the power transfer phase. The timing of the disconnecting is dependent on the local time reference. A mode controller (313) switches between a first operational mode and a second operational mode for the power transfer time intervals in response to a reliability measure for the synchronization.

Abstract: A power receiver receives a wireless power transfer from a power transfer signal generated by a wireless power transmitter during a power transfer phase. The power transfer signal employing a repeating time frame during the power transfer phase where the frame comprises at least a power transfer time interval and a foreign object detection time interval. The power receiver comprises a synchronizer (311) which synchronizes a local time reference to the repeating time frame and a load controller (309) which disconnects a load (303) during at least part of the foreign object time detection time intervals during at least part of the power transfer phase. The timing of the disconnecting is dependent on the local time reference. A mode controller (313) switches between a first operational mode and a second operational mode for the power transfer time intervals in response to a reliability measure for the synchronization.

Abstract: A power transfer device is a power transmitter (201) or a power receiver (205) conducting power transfer using an electromagnetic power transfer signal employing a repeating time frame comprising a power transfer time interval and an object detection time interval. A power transfer circuit (303, 307) comprises a power transfer coil (203, 207) receiving or generating the power transfer signal during the power transfer time intervals. A communicator (315, 323) communicates with the other device via an electromagnetic communication signal. A communication resonance circuit (317, 321) comprises a communication antenna (319, 325) for transmitting or receiving the electromagnetic communication signal. During the communication, the communication resonance circuit (317, 321) provides a resonance at a first resonance frequency to the communicator (315, 323).