US 12,489,321 B2
Wireless power transfer and communication
Wilhelmus Gerardus Maria Ettes, Leeuwarden (NL); Klaas Jacob Lulofs, Veldhoven (NL); Pascal Leonard Maria Theodoor Lebens, Eindhoven (NL); and Friso Rietstra, Drachten (NL)
Assigned to Koninklijke Philips N.V., Eindhoven (NL)
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
Filed on Feb. 20, 2024, as Appl. No. 18/581,463.
Application 18/581,463 is a continuation of application No. 17/779,185, granted, now 11,936,208, previously published as PCT/EP2020/084427, filed on Dec. 3, 2020.
Claims priority of application No. 19214922 (EP), filed on Dec. 10, 2019.
Prior Publication US 2024/0195228 A1, Jun. 13, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H02J 50/60 (2016.01); H01F 38/14 (2006.01); H02J 50/12 (2016.01)
CPC H02J 50/60 (2016.02) [H01F 38/14 (2013.01); H02J 50/12 (2016.02)] 14 Claims
OG exemplary drawing
 
1. 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,
wherein the driver circuit is arranged to generate the drive signal for the transmitter coil so as to generate a power transfer signal during at least one power transfer time interval of a repeating time frame,
wherein the driver coil is arranged to generate the drive signal for the transmitter coil so as to generate an electromagnetic test signal during at least one foreign object detection time interval of the repeating time frame;
a first plurality of balanced detection coils coupled in series,
wherein the first plurality of balanced detection coils comprises a first detection coil and a second detection coil,
wherein the first detection coil and the second detection coil are arranged such that a first signal induced in the first detection coil by an electromagnetic field generated by the transmitter coil is compensated by a second signal induced in the second detection coil by the electromagnetic field generated by the transmitter coil;
a foreign object detector circuit coupled to the first plurality of balanced detection coils,
wherein the foreign object detector circuit is arranged to perform foreign object detection during the foreign object detection time interval,
wherein the foreign object detector circuit is arranged to detect a foreign object in response to a property of a signal meeting a foreign object detection criterion,
wherein the signal is from the first plurality of balanced detection coils; and
a compensation circuit,
wherein the compensation circuit is arranged to generate a compensation drive signal,
wherein the compensation drive signal offsets a combined voltage of the first plurality of detection coils.