Dynamic multi-coil tuning

Patent metadata

Field	Value
Publication number	US-11935692-B2
Application number	US-202217963481-A
Country	US
Kind code	B2
Filing date	Oct 11, 2022
Priority date	Jan 6, 2020
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

Systems, methods and apparatus for wireless charging are disclosed. A wireless charging device has a plurality of charging cells provided on a first surface and a processor configured to provide a charging current to a first charging coil in a surface of the wireless charging device, determine that an impedance of a resonant circuit has varied from a threshold or setpoint impedance, and restore the threshold or setpoint impedance by modifying frequency of the charging current. The resonant circuit may include the first charging coil. A method for operating the wireless charging device includes providing a charging current to a first charging coil in a surface of the wireless charging device, determining that an impedance of a resonant circuit has varied from a threshold or setpoint impedance, and restoring the threshold or setpoint impedance by modifying frequency of the charging current. The resonant circuit may include the charging coil.

First claim

What is claimed is:

1. A method for operating a wireless charging device, comprising:
providing a charging current to a resonant circuit when the resonant circuit includes a first transmitting coil of the wireless charging device;
coupling a second transmitting coil of the wireless charging device to the resonant circuit;
determining a change in impedance of the resonant circuit after coupling the second transmitting coil to the resonant circuit;
modifying frequency of the charging current responsive to the change in the impedance of the resonant circuit, wherein the charging current is provided at a first frequency before the second transmitting coil is coupled to the resonant circuit and provided at a second frequency after the second transmitting coil is coupled to the resonant circuit; and
using a lookup table to determine the second frequency.

2. The method of claim 1 , wherein the change in frequency of the charging current is configured to restore a nominal impedance of the resonant circuit.

3. The method of claim 1 , wherein the first frequency corresponds to a first resonant frequency associated with the resonant circuit before the second transmitting coil is coupled to the resonant circuit.

4. The method of claim 1 , wherein the second frequency corresponds to a second resonant frequency associated with the resonant circuit after the second transmitting coil is coupled to the resonant circuit.

5. The method of claim 1 , wherein changes in impedance of the resonant circuit are tracked using a current sense feedback loop.

Assignees

• Aira Inc

Inventors

• Goodchild Eric Heindel
• Winters John

Classifications

• H01F38/14 Primary

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title

• H02J7/02

  for charging batteries from AC mains by converters · CPC title

• H02J50/12

  of the resonant type · CPC title

• H02J50/40

  using two or more transmitting or receiving devices (H02J50/50 takes precedence) · CPC title

• H02J50/402 Primary

  the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas · CPC title