US 12,463,470 B2
Slotted foreign object detection during wireless power transfer
Mark Melone, Frankfort, IL (US); Alberto Peralta, Chicago, IL (US); and Michael Katz, Glen Ellyn, IL (US)
Assigned to NuCurrent, Inc., Chicago, IL (US)
Filed by NuCurrent, Inc., Chicago, IL (US)
Filed on Apr. 30, 2025, as Appl. No. 19/195,504.
Application 19/195,504 is a continuation of application No. 18/778,080, filed on Jul. 19, 2024.
Application 18/778,080 is a continuation of application No. 18/341,513, filed on Jun. 26, 2023, granted, now 12,046,924, issued on Jul. 23, 2024.
Application 18/341,513 is a continuation of application No. 17/707,702, filed on Mar. 29, 2022, granted, now 11,689,063, issued on Jun. 27, 2023.
Application 17/707,702 is a continuation of application No. 17/172,922, filed on Feb. 10, 2021, granted, now 11,289,952, issued on Mar. 29, 2022.
Prior Publication US 2025/0260268 A1, Aug. 14, 2025
Int. Cl. H02J 50/12 (2016.01); H02J 50/40 (2016.01); H02J 50/60 (2016.01); H02J 50/80 (2016.01)
CPC H02J 50/60 (2016.02) [H02J 50/402 (2020.01); H02J 50/80 (2016.02)] 20 Claims
OG exemplary drawing
 
1. A wireless power transmitter comprising:
an inverter that is operable to (i) receive, as input, a direct current (DC) voltage signal having a voltage level and a drive signal having an operating frequency and (ii) produce an alternating current (AC) signal based on the DC voltage signal and the drive signal that are provided as input to the inverter;
a tuning circuit that is operable to (i) receive the AC signal that is produced by the inverter and (ii) tune the AC signal;
a transmission antenna that is operable to emit an alternating electromagnetic field in accordance with the AC signal that is produced by the inverter and tuned by the tuning circuit; and
at least one processor;
at least one non-transitory machine-readable medium; and
executable code stored on the at least one non-transitory machine-readable medium that, when executed by the at least one processor, causes the wireless power transmitter to:
detect a presence of a wireless power receiver that is couplable with the wireless power transmitter;
after detecting the presence of the wireless power receiver, begin engaging in a period of wireless power transfer with the wireless power receiver during which the wireless power transmitter emits, via the transmission antenna, an alternating electromagnetic field that delivers a wireless power signal to the wireless power receiver;
while engaging in the period of wireless power transfer with the wireless power receiver:
determine whether a foreign object has been inserted into the alternating electromagnetic field that delivers the wireless power signal to the wireless power receiver by:
detecting that a given amount of time has elapsed since a prior reference point during the period of wireless power transfer with the wireless power receiver; and
in response to detecting that the given amount of time has elapsed since the prior reference point, (i) temporarily stopping emission of the alternating electromagnetic field that delivers the wireless power signal to the wireless power receiver for a temporary interval of time during the period of wireless power transfer with the wireless power receiver and (ii) after the wireless power transmitter has temporarily stopped emission of the alternating electromagnetic field that delivers the wireless power signal to the wireless power receiver, performing a foreign object detection (FOD) process during the temporary interval of time; and
after the FOD process is completed and the temporary interval of time has ended, resume emission of the alternating electromagnetic field that delivers the wireless power signal to the wireless power receiver during the period of wireless power transfer with the wireless power receiver.