Method and apparatus for wireless power in-band signaling by load generation

Patent metadata

Field	Value
Publication number	US-2016197486-A1
Application number	US-201514825592-A
Country	US
Kind code	A1
Filing date	Aug 13, 2015
Priority date	Jan 7, 2015
Publication date	Jul 7, 2016
Grant date	—

Abstract

Exemplary implementations are directed to wireless power in-band signaling by load generation. An apparatus for communicating with a wireless power transmitter is provided. The apparatus comprises a receiver configured to generate a voltage based on wirelessly received charging power from the transmitter. The apparatus comprises a load configurable to be coupled to and decoupled from the receiver. The apparatus comprises a switching circuit configured to encode a communication to the transmitter by adjusting an average power dissipated by the load detectable by the transmitter. The average power is based on a duty cycle with which the switching circuit couples and decouples the load from the receiver under control of a control signal.

First claim

What is claimed is:

1 . An apparatus for communicating with a wireless power transmitter, the apparatus comprising:
a receiver configured to generate a voltage based on wirelessly received charging power from the transmitter; a load configurable to be coupled to and decoupled from the receiver; and a switching circuit configured to encode a communication to the transmitter by adjusting an average power dissipated by the load detectable by the transmitter, the average power based on a duty cycle with which the switching circuit couples and decouples the load from the receiver under control of a control signal.

2 . The apparatus of claim 1 , wherein the switching circuit is configured to adjust the average power dissipated by the load by selectively adjusting the duty cycle between a first value and a second value greater than the first value.

3 . The apparatus of claim 1 , wherein the switching circuit comprises a transistor configured to electrically connect the load to a ground voltage in a coupled state and electrically isolate the load from the ground voltage in an uncoupled state.

4 . The apparatus of claim 1 , wherein the load comprises one or more of a resistor, a diode, an inductor, a current source comprising a transistor, or any combination thereof.

5 . The apparatus of claim 1 , wherein the communication comprises at least one of:
a message indicative of one or more characteristics relating to power transfer between the transmitter and the receiver; or an indication of a presence of the receiver in a charging region of the transmitter; or a load condition maintained for a predetermined interval of time to confirm a presence of the receiver in the charging region of the transmitter; or any combination thereof.

6 . The apparatus of claim 1 , wherein the communication is encoded as a modulation of a level of the charging power wirelessly received by the receiver from the transmitter via a magnetic field.

7 . The apparatus of claim 1 , wherein the switching circuit is configured to pull down a level of the control signal to reduce the average power dissipated by the load when the voltage exceeds a predetermined value.

8 . The apparatus of claim 1 , further comprising:
a current sensor configured to measure a current flowing through the load; a multiplier configured to determine the average power by multiplying the voltage by the current; and a driver circuit configured to control the switching circuit based on the determined average power.

9 . The apparatus of claim 1 , further comprising:
a multiplier configured to determine the average power by multiplying the voltage by another voltage appearing across the load; and a driver circuit configured to control the switching circuit based on the determined average power.

10 . A method of communicating between a wireless power transmitter and a wireless power receiver, the method comprising:
wirelessly receiving charging power from the transmitter to generate a voltage at the receiver, and encoding a communication to the transmitter by adjusting an average power dissipated by a load of the receiver detectable by the transmitter, the average power based on a duty cycle at which the load is coupled to and decoupled from the receiver under control of a control signal.

11 . The method of claim 10 , wherein adjusting the average power dissipated by the load comprises selectively adjusting the duty cycle between a first value and a second value greater than the first value.

12 . The method of claim 10 , wherein the load is coupled to the receiver when the load is electrically connected to a ground voltage by a transistor and the load is decoupled from the receiver when the load is electrically isolated from the ground voltage by the transistor.

13 . The method of claim 10 , wherein the load comprises one or more of a resistor, a diode, an inductor, a current source comprising a transistor, or any combination thereof.

14 . The method of claim 10 , wherein the communication comprises at least one of:
a message indicative of one or more characteristics relating to power transfer between the transmitter and the receiver; or an indication of a presence of the receiver in a charging region of the transmitter; or a load condition maintained for a predetermined interval of time to confirm a presence of the receiver in the charging region of the transmitter; or any combination thereof.

15 . The method of claim 10 , further comprising pulling down a level of the control signal to reduce the average power dissipated by the load when the voltage exceeds a predetermined value.

16 . An apparatus for communicating with a wireless power transmitter, the apparatus comprising:
means for generating a voltage based on wirelessly received charging power from the transmitter; and means for encoding a communication to the transmitter by adjusting an average power dissipated by a load of the apparatus detectable by the transmitter, the average power based on a duty cycle with which the means for encoding the communication couples and decouples the load from the apparatus under control of a control signal.

17 . The apparatus of claim 16 , wherein the means for encoding the communication further comprises means for adjusting the average power dissipated by the load by selectively adjusting the duty cycle between a first value and a second value greater than the first value.

18 . The apparatus of claim 16 , wherein the means for encoding the communication comprises a transistor configured to electrically connect the load to a ground voltage in a coupled state and electrically isolate the load from the ground voltage in an uncoupled state.

19 . The apparatus of claim 16 , wherein the load comprises one or more of a resistor, a diode, an inductor, a current source comprising a transistor, or any combination thereof.

20 . The apparatus of claim 16 , wherein the means for encoding the communication comprises means for pulling down a level of the control signal to reduce the average power dissipated by the load when the voltage exceeds a predetermined value.

Assignees

• Qualcomm Inc

Inventors

• Von Novak Iii William Henry
• Irish Linda Stacey

Classifications

• H02J50/12

  of the resonant type · CPC title

• H02J7/42 Primary

  with electronic devices having internal batteries, e.g. mobile phones · CPC title

• H04B5/45

  Transponders · CPC title

• H04B5/26

  using coils · CPC title

• H02J5/005 Primary

  Electricity · mapped topic