Abstract: A power transmitter (101) of a wireless power transfer system comprises a resonance including a transmitter coil (103) for generating a power transfer signal for wirelessly transferring power to a power receiver (105). Further, a driver (1303) generates a drive signal for the resonance circuit (201) and a message receiver (1305) is arranged to receive messages from the power receiver (105). A power loop controller (1307) implements a power control loop by adapting the power of the drive signal in response to power control messages received from the power receiver (105). However, the regulation is subject to a constraint of at least one of a current or voltage of the resonance circuit and a power of the drive signal being below a maximum limit. Further, the power transmitter (101) comprises an adapter (1309) which adapts the maximum limit in response to a load indication indicative of a loading of the power transfer signal by the power receiver (105).

Abstract: A power transmitter (101) provides power to a power receiver (105) via an electromagnetic power transfer signal. The power transmitter (101) comprises an output circuit (302, 103) with a transmitter coil (103) generating the power transfer signal in response to a drive signal generated by a driver (301). A configuration controller (303) switches between power transfer configurations having different maximum power limits and voltage amplitudes for the drive signal. A transmitter (307) transmits a power configuration message to the power receiver (105) comprising data indicative of a voltage amplitude for a first power transfer configuration a receiver (305) receives a power transfer configuration change request message from the power receiver (105). The configuration controller (303) switches the power transmitter (101) to the first power transfer configuration in response to the power transfer configuration change request message.

Abstract: The invention proposes a method of encoding data packet by encoding type information and size information of said data packet into the same field. The invention also proposes a method of processing data packets received. The data packet comprises a header part and a message part. The header part comprises at least one bit for indicating the type of said data packet, said method comprising a step 101 of obtaining the size information of said data packet based on said at least one bit.

Abstract: A power transmitter (101) provides power to a power receiver (105) via an electromagnetic power transfer signal. The power transmitter (101) comprises an output circuit (302, 103) with a transmitter coil (103) generating the power transfer signal in response to a drive signal generated by a driver (301). A configuration controller (303) switches between power transfer configurations having different maximum power limits and voltage amplitudes for the drive signal. A transmitter (307) transmits a power configuration message to the power receiver (105) comprising data indicative of a voltage amplitude for a first power transfer configuration a receiver (305) receives a power transfer configuration change request message from the power receiver (105). The configuration controller (303) switches the power transmitter (101) to the first power transfer configuration in response to the power transfer configuration change request message.

Abstract: A power transmitter (101) comprises a transmitter coil (103) for generating the power transfer signal during a power transfer phase. A driver (201) generates a drive signal for the transmitter coil (103) to generate the power transfer signal during the power transfer phase. A communicator (205) receives messages from the power receiver (105) and a controller (203) is arranged to, during the power transfer phase, generate a reduced power time interval during which a power level of the power transfer signal is reduced where the reduced power time interval is generated in response to the communicator (205) receiving a reduced power time interval request message from the power receiver (105). The power receiver (105) may generate a request message when e.g. a change in operating mode occurs. The power receiver (105) may ensure that a request message, and thus a reduced power time interval, is only generated when the power receiver can handle a power interruption for the power transfer signal.

Abstract: A wireless power transfer system comprises at least one power receiver (105) for receiving a power transfer from the power transmitter (101) via a wireless inductive power transfer signal. Configurers (207, 306) of the power transmitter and receiver may perform a configuration process to determine a set of power transfer parameter values which are used in a first power transfer. The power transfer parameter values and a first identity for the first power receiver (105) are stored. After a detection of an absence of the power receiver by a first controller (211), a detector (213) may detect a presence of a candidate power receiver. If the candidate power receiver is detected within a given duration and has an identity matching the first identity, an initialization processor (215) initializes a second power transfer using the set of stored parameter values. Otherwise it discards the set of stored parameter values.

Abstract: A wireless power transfer system comprises at least one power receiver (105) for receiving a power transfer from the power transmitter (101) via a wireless inductive power transfer signal. Configurers (207, 306) of the power transmitter and receiver may perform a configuration process to determine a set of power transfer parameter values which are used in a first power transfer. The power transfer parameter values and a first identity for the first power receiver (105) are stored. After a detection of an absence of the power receiver by a first controller (211), a detector (213) may detect a presence of a candidate power receiver. If the candidate power receiver is detected within a given duration and has an identity matching the first identity, an initialization processor (215) initializes a second power transfer using the set of stored parameter values. Otherwise it discards the set of stored parameter values.

Abstract: A wireless power transfer system comprises a power transmitter (101) wirelessly providing power to a power receiver (105) via an electromagnetic power transfer signal. The power transmitter (101) comprises a transmitter coil (103) generating the power transfer signal and a driver (201) generating a drive signal for the transmitter coil (103) to generate the power transfer signal. A foreign object detector (207) executes a foreign object detection operation arranged to detect a presence of a foreign object in response to a property of the drive signal. A communicator (205) receives a power operating point indication from the power receiver (105) which represents a load power for a load of the power receiver (105). An adapter (209) adapts the foreign object detection operation in response to the operating point indication being indicative of a change in the load power meeting a criterion.

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: The invention proposes a method of encoding data packet by encoding type information and size information of said data packet into the same field. The invention also proposes a method of processing data packets received. The data packet comprises a header part and a message part. The header part comprises at least one bit for indicating the type of said data packet, said method comprising a step 101 of obtaining the size information of said data packet based on said at least one bit.

Abstract: The invention proposes a method of encoding data packet by encoding type information and size information of said data packet into the same field. The invention also proposes a method of processing data packets received. The data packet comprises a header part and a message part. The header part comprises at least one bit for indicating the type of said data packet, said method comprising a step 101 of obtaining the size information of said data packet based on said at least one bit.

Abstract: A power transmitter (101) provides power to a power receiver (105) via an electromagnetic power transfer signal. The power transmitter (101) comprises an output circuit (302, 103) with a transmitter coil (103) generating the power transfer signal in response to a drive signal generated by a driver (301). A configuration controller (303) switches between power transfer configurations having different maximum power limits and voltage amplitudes for the drive signal. A transmitter (307) transmits a power configuration message to the power receiver (105) comprising data indicative of a voltage amplitude for a first power transfer configuration a receiver (305) receives a power transfer configuration change request message from the power receiver (105). The configuration controller (303) switches the power transmitter (101) to the first power transfer configuration in response to the power transfer configuration change request message.

Abstract: A power transmitter (101) of a wireless power transfer system comprises a resonance including a transmitter coil (103) for generating a power transfer signal for wirelessly transferring power to a power receiver (105). Further, a driver (1303) generates a drive signal for the resonance circuit (201) and a message receiver (1305) is arranged to receive messages from the power receiver (105). A power loop controller (1307) implements a power control loop by adapting the power of the drive signal in response to power control messages received from the power receiver (105). However, the regulation is subject to a constraint of at least one of a current or voltage of the resonance circuit and a power of the drive signal being below a maximum limit. Further, the power transmitter (101) comprises an adapter (1309) which adapts the maximum limit in response to a load indication indicative of a loading of the power transfer signal by the power receiver (105).

Abstract: A power transmitter (101) of a wireless power transfer system provides wireless power to a power receiver (105). The power transmitter (101) comprises a variable resonance circuit (201) generating an inductive power transfer signal in response to a drive signal. The resonance circuit comprises a capacitive and inductive impedance (201, 203), at least one of which is variable. The resonance frequency can be varied by at least one of the impedances being variable in response to a control signal. A driver (205) generates the drive signal with a variable drive frequency. A frequency modulator (305) applies frequency modulation to the drive signal by varying the variable drive frequency in response to data values to be transmitted to the power receiver (105). An adapter (309) generates the control signal in response to the data values such that the variable resonance frequency follows the variations in the drive frequency resulting from the frequency modulation of the drive signal.

Abstract: A wireless power transfer system comprises a power transmitter (101) wirelessly providing power to a power receiver (105) via an electromagnetic power transfer signal. The power transmitter (101) comprises a transmitter coil (103) generating the power transfer signal and a driver (201) generating a drive signal for the transmitter coil (103) to generate the power transfer signal. A foreign object detector (207) executes a foreign object detection operation arranged to detect a presence of a foreign object in response to a property of the drive signal. A communicator (205) receives a power operating point indication from the power receiver (105) which represents a load power for a load of the power receiver (105). An adapter (209) adapts the foreign object detection operation in response to the operating point indication being indicative of a change in the load power meeting a criterion.

Abstract: A wireless power transfer system comprises at least one power receiver (105) for receiving a power transfer from the power transmitter (101) via a wireless inductive power transfer signal. Configurers (207, 306) of the power transmitter and receiver may perform a configuration process to determine a set of power transfer parameter values which are used in a first power transfer. The power transfer parameter values and a first identity for the first power receiver (105) are stored. After a detection of an absence of the power receiver by a first controller (211), a detector (213) may detect a presence of a candidate power receiver. If the candidate power receiver is detected within a given duration and has an identity matching the first identity, an initialization processor (215) initializes a second power transfer using the set of stored parameter values. Otherwise it discards the set of stored parameter values.

Abstract: A wireless power transfer system comprises at least one power receiver (105) for receiving a power transfer from the power transmitter (101) via a wireless inductive power transfer signal. Configurers (207, 306) of the power transmitter and receiver may perform a configuration process to determine a set of power transfer parameter values which are used in a first power transfer. The power transfer parameter values and a first identity for the first power receiver (105) are stored. After a detection of an absence of the power receiver by a first controller (211), a detector (213) may detect a presence of a candidate power receiver. If the candidate power receiver is detected within a given duration and has an identity matching the first identity, an initialization processor (215) initializes a second power transfer using the set of stored parameter values. Otherwise it discards the set of stored parameter values.

Abstract: A power transmitter (101) is arranged to transfer power to a power receiver (105) using a wireless inductive power signal. The power transmitter (101) comprises a power signal generator (207) which drives an inductor (103) to provide the power signal to an inductor of the power receiver (105). A power loop control is employed by the power receiver (105) providing power control error messages to the power transmitter (101). The power transmitter (101) comprises a query message processor (209) which can detect a query message received from the power receiver (105) using load modulation of the power signal. A modification processor (211) is arranged to modify a response of the power loop controller to the power control error messages dependent on the query message. The power receiver (105) can detect the modifications to the operation of the power control and thus can interpret this as a response to the query message.

Abstract: A power transmitter (501) for a wireless power transfer system includes a parallel resonance circuit (601) comprising at a transmitter coil (503) for generating the power transfer signal. A power source (605) has a current sink terminal and a power source terminal providing current to the parallel resonance circuit (601) with a limited rate of change of the current drawn. A first switch element (607) is coupled between a first end of the parallel resonance circuit (601) and the current sink terminal. A second switch element (609) is coupled between the other end and the current sink terminal. A driver (611) generates a cyclic drive signal such that each cycle comprises a two time intervals in which one switch element (607, 609) is closed and the other (607, 609) is open; and a third time interval in which both the first switch element (607) and the second switch element (609) are closed, the third time interval being between the other two intervals.