Detection and protection of devices within a wireless power system

• US 9,935,502 B2
• Filed: 08/04/2015
• Issued: 04/03/2018
• Est. Priority Date: 03/11/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Low, Zhen Ning, Mudrick, Adam A., Estrada, Sergio P.
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): Piggush, Aaron
• Application Number:
  US14/818,161
• Publication Number:
  US 20150340906A1
• Time in Patent Office: 973 Days
• Field of Search: 320108, 320115, 320134
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Exemplary embodiments are directed to detecting and limiting power transfer to non-compliant devices. A method may include detecting one or more non-compliant devices positioned within a charging region of a wireless power transmitter. The method may further include limiting an amount of power delivered to at least one of the one or more non-compliant devices.

Claims

1. A method for wirelessly transferring power, comprising:

requesting a receiver circuit comprising a receive antenna and a power conversion circuit and positioned within a charging region of a wireless power transmitter to disconnect the receive antenna from the power conversion circuit for a period of time;

measuring one or more properties of the wireless power transmitter indicative of one or more non-compliant devices wirelessly receiving power from the wireless power transmitter during the period of time;

detecting the one or more non-compliant devices positioned within the charging region of the wireless power transmitter based on the one or more properties of the wireless power transmitter; and

reducing an amount of power transmitted from the wireless power transmitter to at least one of the one or more non-compliant devices.

2. The method of claim 1, wherein reducing the amount of power transmitted from the wireless power transmitter to the at least one of the one or more non-compliant devices comprises signaling the receiver circuit positioned within the charging region to reduce the receiver circuit'"'"'s load impedance.

3. The method of claim 2, wherein reducing the receiver circuit'"'"'s load impedance comprises increasing an amount of power transmitted to the receiver circuit.

4. The method of claim 1, wherein the one or more properties of the wireless power transmitter comprise at least one of:

a supply voltage, a supply current, a radiofrequency (RF) voltage, and an RF current.

5. The method of claim 1, wherein measuring the one or more properties of the wireless power transmitter comprises measuring a radiofrequency (RF) voltage of a power amplifier of the wireless power transmitter, the detecting of the one or more non-compliant devices comprising determining whether the one or more non-compliant devices are receiving power transmitted from the wireless power transmitter via determining whether the RF voltage has decreased.

6. An apparatus for wirelessly transferring power, comprising:

a wireless power transmitter configured to wirelessly transmit power at a level sufficient to power or charge a receiver circuit comprising a receive antenna and a power conversion circuit and positioned within a charging region of the wireless power transmitter; and

a controller configured to;

request the receiver circuit positioned within the charging region of the wireless power transmitter to disconnect the receive antenna from the power conversion circuit for a period of time;

measure one or more properties of the wireless power transmitter indicative of one or more non-compliant devices wirelessly receiving power from the wireless power transmitter during the period of time;

detect the one or more non-compliant devices positioned within the charging region of the wireless power transmitter based on the one or more properties of the wireless power transmitter; and

reduce an amount of power transmitted from the wireless power transmitter to at least one of the one or more non-compliant devices.

7. The apparatus of claim 6, wherein the controller is further configured to signal the receiver circuit positioned within the charging region to reduce the receiver circuit'"'"'s load impedance.

8. The apparatus of claim 7, wherein the controller is further configured to increase an amount of power transmitted from the wireless power transmitter to the receiver circuit.

9. The apparatus of claim 6, wherein the measured one or more properties of the wireless power transmitter comprise at least one of:

a supply voltage, a supply current, a radiofrequency (RF) voltage, and an RF current.

10. The apparatus of claim 6, wherein the controller is further configured to:

measure a radiofrequency (RF) voltage of a power amplifier of the wireless power transmitter; and

determine whether the one or more non-compliant devices are receiving power transmitted from the wireless power transmitter via determining whether the RF voltage has decreased.