US 12,074,455 B2
Object detection in wireless charging systems and related systems, methods, and devices
Santosh Manjunath Bhandarkar, Chandler, AZ (US)
Assigned to Microchip Technology Incorporated, Chandler, AZ (US)
Filed by Microchip Technology Incorporated, Chandler, AZ (US)
Filed on Jul. 21, 2022, as Appl. No. 17/814,181.
Claims priority of provisional application 63/203,413, filed on Jul. 21, 2021.
Prior Publication US 2023/0024604 A1, Jan. 26, 2023
Int. Cl. H02J 50/60 (2016.01); H02J 50/10 (2016.01); H02J 50/40 (2016.01)
CPC H02J 50/60 (2016.02) [H02J 50/10 (2016.02); H02J 50/40 (2016.02)] 16 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
an input terminal to receive a measurement voltage potential at a selected transmit coil of a plurality of transmit coils of a wireless power transmitter; and
a processing core to:
determine a transmit coil voltage potential at the selected transmit coil responsive to the measurement voltage potential;
determine an input power provided by a voltage source to the wireless power transmitter;
determine a transmitter power loss as a function of the transmit coil voltage potential and polynomial coefficients determined from a calibration operation;
determine a transmitted power of wireless power transmitted to a wireless power receiver based, at least in part, on the determined input power and the determined transmitter power loss;
determine a power loss responsive to the determined transmitted power and a received power indicated by the wireless power receiver; and
determine that a foreign object is detected responsive to a determination that determined power loss is greater than predetermined threshold power,
in the calibration operation, for respective transmit coils of the plurality of transmit coils:
select a respective transmit coil of the plurality of transmit coils;
increment a rail voltage potential of the wireless power transmitter from a first rail voltage potential to a last rail voltage potential; and
determine the transmit coil voltage potential and the input power for respective increments of the rail voltage potential.