US 12,278,503 B2
Wireless power systems with foreign object detection
Adam L. Schwartz, Redwood City, CA (US); Niloofar Rashidi Mehrabadi, Santa Clara, CA (US); and Hossein Sepahvand, Santa Clara, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Oct. 11, 2023, as Appl. No. 18/484,885.
Application 18/484,885 is a continuation of application No. 18/327,721, filed on Jun. 1, 2023, granted, now 11,831,178.
Application 18/484,885 is a continuation of application No. 18/327,750, filed on Jun. 1, 2023.
Application 18/327,721 is a continuation of application No. 17/109,793, filed on Dec. 2, 2020, abandoned.
Application 18/327,721 is a continuation of application No. 17/109,793, filed on Dec. 2, 2020, abandoned.
Claims priority of provisional application 63/012,813, filed on Apr. 20, 2020.
Claims priority of provisional application 62/943,043, filed on Dec. 3, 2019.
Prior Publication US 2024/0039341 A1, Feb. 1, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H02J 50/60 (2016.01); H02J 50/12 (2016.01); H02J 50/70 (2016.01); H02J 50/80 (2016.01)
CPC H02J 50/60 (2016.02) [H02J 50/12 (2016.02); H02J 50/70 (2016.02); H02J 50/80 (2016.02)] 19 Claims
OG exemplary drawing
 
1. A wireless power transmitter comprising:
wireless power transmitting circuitry having a wireless power transmitting coil that transmits wireless power signals; and
control circuitry coupled to the wireless power transmitting circuitry that:
measures a present quality factor of the wireless power transmitting coil by:
using measurement circuitry to measure a complex impedance of the wireless power transmitting coil; and
determining the present quality factor from a phase angle of the complex impedance;
determines a change between the measured present quality factor and a baseline quality factor;
responsive to the change between the measured quality factor and the baseline quality factor exceeding a threshold, attempts to initiate digital communication with a wireless power receiver; and
detects a foreign object responsive to the change between the measured present quality factor and the baseline quality factor and a lack of response to the attempt to initiate digital communication.