US 12,316,142 B2
Wireless power transmitter and method of operation therefor
Pascal Leonard Maria Theodoor Lebens, Eindhoven (NL); Wilhelmus Gerardus Maria Ettes, Leeuwarden (NL); Klaas Jakob Lulofs, Veldhoven (NL); and Johannes Wilhelmus Draak, Limburg (NL)
Assigned to ]Koninklije Philips N.V., Eindhoven (NL)
Appl. No. 18/266,305
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
PCT Filed Dec. 10, 2021, PCT No. PCT/EP2021/085136
§ 371(c)(1), (2) Date Jun. 9, 2023,
PCT Pub. No. WO2022/128762, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 20215742 (EP), filed on Dec. 18, 2020.
Prior Publication US 2024/0048002 A1, Feb. 8, 2024
Int. Cl. H02J 50/90 (2016.01); H02J 50/12 (2016.01)
CPC H02J 50/90 (2016.02) [H02J 50/12 (2016.02)] 22 Claims
OG exemplary drawing
 
3. A power transmitter comprising:
a transmitter coil;
a driver circuit,
wherein the driver circuit is arranged to generate a drive signal for the transmitter coil, so as to generate a power transfer signal during at least one power transfer time interval,
wherein the driver circuit is arranged to generate the drive signal for the transmitter coil so as to generate a test signal during at least one measurement time interval;
a plurality of groups of balanced detection coils,
wherein each group of the plurality of groups balanced detection coils comprises at least two balanced detection coils,
wherein each of the at least two balanced detection coils is arranged such that first signals induced by the transmitter coil compensate each other;
an estimation circuit,
wherein the estimation circuit is arranged to determine a coupling factor,
wherein the coupling factor is for an electromagnetic coupling between the transmitter coil and a receiver coil in response to a least one first signals from the plurality of groups of balanced detection coils during the at least one measurement time interval,
wherein the estimation circuit is arranged to determine the coupling factor as a decreasing coupling factor for an increasing amplitude of a difference between at least two first signals produced by at least two of the plurality of groups of balanced detection coils.