Shared power converter for a wireless transmitter device

Patent metadata

Field	Value
Publication number	US-10734840-B2
Application number	US-201715422345-A
Country	US
Kind code	B2
Filing date	Feb 1, 2017
Priority date	Aug 26, 2016
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A transmitter device is configured to transfer energy to multiple receiver devices. The transmitter device includes multiple transmitter coils, and a shared power converter is coupled to each transmitter coil. The shared power converter includes a leading half bridge and multiple trailing half bridges. Each transmitter coil is coupled between the leading half bridge and a respective one of the trailing half bridges. The shared power converter is dynamically configurable in that the leading half bridge may be coupled to multiple trailing half bridges when energy is to be transferred wirelessly to two or more receiver devices. The leading half bridge simultaneously operates with each trailing half bridge as an independent full-bridge phase shift inverter. A signal supplied to each transmitter coil is independently regulated by controlling a phase shift of a respective trailing half bridge with respect to the leading half bridge.

First claim

What is claimed is:

1. A shared power converter circuit for a wireless energy transfer system, the shared power converter circuit comprising:
a leading half bridge coupled between first and second input nodes of the shared power converter circuit and having a first intermediate node;
multiple transmitter coils, each coupled to the first intermediate node; and
multiple trailing half bridges coupled between the first and second input nodes, each trailing half bridge having a respective intermediate node coupled to a distinct one of the multiple transmitter coils; wherein
the leading half bridge is configured to simultaneously operate with each trailing half bridge as an independent full-bridge phase shift inverter by:
applying a first voltage at the first intermediate node;
applying a second voltage at the respective intermediate node of a one of the multiple trailing half bridges; and
controlling a phase shift of the second voltage with respect to the first voltage; wherein
a one of the multiple transmitter coils is between the first intermediate node and a second intermediate node.

2. The shared power converter circuit of claim 1 , wherein the leading half bridge comprises:
a first switching element connected to the first intermediate node; and
a second switching element connected to the first intermediate node.

3. The shared power converter circuit of claim 2 , wherein each trailing half bridge comprises:
a third switching element connected to the second intermediate node; and
a fourth switching element connected to the second intermediate node.

4. A wireless transmitter device, comprising:
a first transmitter coil;
a second transmitter coil;
a shared power converter coupled to the first and second transmitter coils, the shared power converter comprising:
a leading half bridge comprising:
a first switching element coupled between a power supply and a first intermediate node; and
a second switching element coupled between a ground and the first intermediate node;

a first trailing half bridge comprising:
a third switching element coupled between the power supply and a second intermediate node; and
a fourth switching element coupled between the ground and the second intermediate node, wherein the first transmitter coil is coupled between the first and second intermediate nodes;

a second trailing half bridge comprising:
a fifth switching element coupled between the power supply and a third intermediate node; and
a sixth switching element coupled between the ground and the third intermediate node, wherein the second transmitter coil is coupled between the first and third intermediate nodes; and

a processing device coupled to the shared power converter and configured to operate the shared power converter as a full bridge to transfer energy from the first transmitter coil by:
causing a first switch signal and a second switch signal to be respectively transmitted to the first switching element and the second switching element of the leading half bridge; and
causing a third switch signal and a fourth switch signal to be respectively transmitted to the third switching element and the fourth switching element of the first trailing half bridge; wherein

the first and second switch signals produce a first voltage signal at the first intermediate node;
the third and fourth switch signals produce a second voltage signal at the second intermediate node; and
a phase of the second voltage signal is independent of a phase of the first voltage signal.

5. The wireless transmitter device of claim 4 , wherein:
the full bridge comprises a first full bridge; and
the processing device is further configured to operate the shared power converter as a second full bridge to transfer energy from the second transmitter coil by:
causing a fifth switch signal and a sixth switch signal to be respectively transmitted to the fifth switching element and the sixth switching element of the second trailing half bridge, wherein:
the fifth and sixth switch signals produce a third voltage signal at the third intermediate node; and
a phase of the third voltage signal is independent of the phase of the first voltage signal.

6. The wireless transmitter device of claim 5 , wherein the processing device is configured to create the first and the second full bridges simultaneously.

7. The wireless transmitter device of claim 4 , further comprising a memory coupled to the processing device, the memory configured to store one or more switch signal characteristics for at least:
the first and second switch signals; or
the third and fourth switch signals.

8. The wireless transmitter device of claim 7 , further comprising a signal generator coupled to the processing device, wherein the processing device is further configured to cause the one or more switch signal characteristics to be transmitted to the signal generator, and based on the received one or more switch signal characteristics, the signal generator is configured to:
produce the first and second switch signals and respectively transmit the first and second switch signals to the first switching element and the second switching element of the leading half bridge; or
produce the third and fourth switch signals and respectively transmit the third and fourth switch signals to the third switching element and the fourth switching element of the first trailing half bridge.

9. The wireless transmitter device of claim 4 , further comprising:
first transmitter resonant circuitry coupled between the first trailing half bridge and the first transmitter coil; and
second transmitter resonant circuitry coupled between the second trailing half bridge and the second transmitter coil.

10. A method of operating a wireless transmitter device that is coupled to or includes a shared power converter comprising a leading half bridge and multiple trailing half bridges, wherein a respective transmitter coil is coupled between the leading half bridge and each of the multiple trailing half bridges, the method comprising:
detecting a receiver device on a transmitting surface of the wireless transmitter device; and
forming a full bridge in the shared power converter to transfer energy from the respective transmitter coil to the receiver device, wherein forming the full bridge comprises:
transmitting a first set of switch signals to the leading half bridge; and
transmitting a second set of second switch signals to a respective trailing half bridge that is coupled to the respective transmitter coil, wherein the second set of switch signals is phase-shifted independently with respect to the first set of switch signals.

11. The method of claim 10 , further comprising:
determining one or more switch signal characteristics for the second set of switch signals prior to transmitting the first and second sets of switch signals, wherein the one or more switch signal characteristics comprises a phase difference of the second set of switch signals with respect to a phase of the first set of switch signals; and
transmitting the one or more switch signal characteristics to a signal generator that is coupled to the leading half bridge and to each of the multiple trailing half bridges, wherein the signal generator produces the first set of switch signals and produces the second set of switch signals based on the one or more switch signal characteristics.

12. The method of claim 11 , further comprising determining a receiver device type for the receiver device prior to determining the one or more switch signal characteristics.

13. The method of claim 10 , further comprising:
prior to detecting the receiver device on the tra

Assignees

• Apple Inc

Inventors

• Qiu Weihong
• Moussaoui Zaki
• Dayal Rohan

Classifications

• H02J50/402

  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

• H02J50/12 Primary

  of the resonant type · CPC title

• H02J7/025

  Electricity · mapped topic

• H02J50/40

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