# US 2018/0323647 A1 · Wireless inductive power transfer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323647 A1 - Document ID: US20180323647A1 - Status: Published application - Kind: A1 - Application number: 16/019,609 - Filed: 2018-06-27 - Published: 2018-11-08 - Earliest claimed: 2012-07-30 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: ANDRIES VAN WAGENINGEN; LAURENS HENRICUS SWAANS - Web page: https://patentgrep.com/patent/US20180323647A1 ## CPC - H02J 50/80: involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices - H02J 50/10: using inductive coupling - H04B 5/266: {One coil at each side, e.g. with primary and secondary coils} - H04B 5/79: for data transfer in combination with power transfer - H02J 7/44: between battery management systems and power sources - H02J 7/485: {with provisions for charging different types of batteries} - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H04B: TRANSMISSION ## Abstract An inductive power transfer system is arranged to transfer power from a power transmitter to a power receiver via a wireless power signal. The system supports communication from the power transmitter to the power receiver based on load modulation of the power signal. The power receiver transmitting a first message to the power transmitter which comprises a standby power signal requirement for the power signal during a standby phase. The power transmitter receives the message, and when the system enters the standby phase, the power transmitter provides the power signal in accordance with the standby power signal requirement during. A power receiver configurable standby phase is provided which may for example allow devices to maintain battery charge or to provide fast initialization of the power transfer phase. ## Claims ### Claim 1 A method of operating an inductive power transfer system, the method comprising: generating, by a power transmitter, a wireless power signal for a power receiver when in a power transfer phase; transmitting, by the power receiver, a first message to the power transmitter, the first message comprising a standby power signal requirement for the power signal during a standby phase; receiving, by the power transmitter, the first message; and providing, by the power transmitter, the power signal in accordance with the standby power signal requirement during the standby phase. ### Claim 2 (depends on 1) The method of claim 1, wherein the standby power signal requirement is indicative of a power requirement of the power signal during the standby phase. ### Claim 3 (depends on 2) The method of claim 2, wherein the standby power signal requirement represents a minimum power for a reduced functionality of the power receiver. ### Claim 4 (depends on 3) The method of claim 3, wherein the reduced functionality comprises functionality for initializing a wake-up process for the power receiver. ### Claim 5 (depends on 3) The method of claim 3, wherein the power requirement represents a minimum power for maintaining an energy storage requirement for the power receiver during the standby phase. ### Claim 6 (depends on 1) The method of claim 1, wherein the power transmitter is configured to provide the power signal intermittently during the standby phase, and the standby power signal requirement is indicative of a timing of time intervals in which the power signal is provided. ### Claim 7 (depends on 1) The method of claim 1, wherein the power receiver transmits a wake-up message to the power transmitter during the standby phase; and the power transmitter moves to the power transfer phase in response to receiving the wake-up message. ### Claim 8 (depends on 7) The method of claim 7, wherein the wake-up message is transmitted from the power receiver by load modulation of the power signal during the standby phase. ### Claim 9 (depends on 1) The method of claim 1, wherein the first message indicates a maximum duration of an interval in the standby phase in which no power signal is provided by the power transmitter. ### Claim 10 (depends on 1) The method of claim 1, wherein the power receiver is configured to transmit the first message during the power transfer phase. ### Claim 11 (depends on 1) The method of claim 1, wherein the power transmitter is configured to enter the standby phase in response to receiving an end of power transfer phase message. ### Claim 12 (depends on 1) The method of claim 1, wherein the power receiver charges an internal energy store from the power signal during the standby phase. ### Claim 13 (depends on 1) The method of claim 1, wherein the power transmitter and the power receiver switch from the standby phase to the power transfer phase without entering a configuration phase. ### Claim 14 (depends on 1) The method of claim 1 wherein the power receiver is arranged to transmit the first message during a configuration phase occurring prior to the power transfer phase. ### Claim 15 (depends on 1) The method of claim 1, wherein the power receiver is configured to transmit a second message to the power transmitter indicating an activity to be performed by the power transmitter in response to receiving a wake-up message. ### Claim 16 (depends on 17) The method of claim 17, wherein the second message indicates a phase the power transmitter should enter after a wake-up from the standby phase. ### Claim 17 A method of operating a power transmitter of an inductive power transfer system comprising the power transmitter and a power receiver, the inductive power transfer system supporting communication from the power receiver to the power transmitter based on load modulation, the method comprising: generating a wireless power signal for the power receiver when in a power transfer phase; receiving a first message comprising a standby power signal requirement for the power signal during a standby phase; and providing the power signal in accordance with the standby power signal requirement during the standby phase. ### Claim 18 (depends on 17) The method of claim 17, wherein the standby power signal requirement is indicative of a power requirement of the power signal during the standby phase. ### Claim 19 (depends on 17) The method of claim 17, wherein the standby power signal requirement represents a minimum power for a reduced functionality of the power receiver. ### Claim 20 (depends on 17) The method of claim 17, wherein the power transmitter provides the power signal intermittently during the standby phase, and the standby power signal requirement is indicative of a timing of time intervals in which the power signal is provided. ### Claim 21 (depends on 17) The method of claim 17, wherein the power transmitter transitions to the power transfer phase in response to receiving a wake-up message from the power receiver during the standby phase. ### Claim 22 (depends on 17) The method of claim 17, wherein the first message indicates a maximum duration of an interval in the standby phase in which no power signal is provided by the power transmitter. ### Claim 23 A method of operating a power receiver of an inductive power transfer system comprising a power transmitter for generating a wireless power signal for the power receiver when in a power transfer phase, the inductive power transfer system supporting communication from the power receiver to the power transmitter based on load modulation of the wireless power signal, the method comprising: extracting power from the wireless power signal when in the power transfer phase; transmitting a first message to the power transmitter, the first message comprising a standby power signal requirement for the power signal during a standby phase; and receiving the power signal when in the standby phase. ### Claim 24 A power receiver for an inductive power transfer system comprising a power transmitter for generating a wireless power signal for the power receiver when in a power transfer phase, the inductive power transfer system supporting communication from the power receiver to the power transmitter based on load modulation of the wireless power signal, the power receiver comprising: a power unit for extracting power from the wireless power signal when in the power transfer phase; a transmitter for transmitting a first message to the power transmitter, the first message comprising a standby power signal requirement for the wireless power signal during a standby phase; and a receiver for receiving the power signal when in the standby phase.