Multi-coil system for inductive charging of portable devices at different power levels

Patent metadata

Field	Value
Publication number	US-11411433-B2
Application number	US-202117555293-A
Country	US
Kind code	B2
Filing date	Dec 17, 2021
Priority date	Jan 31, 2006
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

A system for power inductively to a portable device is disclosed. In accordance with an embodiment the system includes a first primary coil that provides power inductively at a first power level and a second primary coil that provides power inductively at a second power level different from the first power level. The first primary coil and the second coil area are different in size and overlap one another partially. The system further includes a communication and control circuit that receives current modulated information in the primary coil that provides power. The received information includes information corresponding to a voltage or current induced by the primary coil that provides power, a unique identification code, and a manufacturer code. The system selects which primary coil to use to charge the portable device based on the received information.

First claim

What is claimed is:

1. A system for providing power inductively to a portable device comprising a battery, a substantially planar spiral-shaped receiver coil and a receiver circuit, the system comprising:
a spiral-shaped first primary coil and a spiral-shaped second primary coil that are each substantially planar and substantially parallel to a surface of the system through which power is provided inductively to the portable device when the portable device is positioned on the surface,
wherein a first coil area is defined by an outer perimeter of the first primary coil and a second coil area is defined by an outer perimeter of the second primary coil, wherein the first coil area and the second coil area are different in size,
wherein the first primary coil comprises two terminal ports defining the overall length of the first primary coil for application of alternating current to the first primary coil and is configured to deliver inductive power to a first type of portable device at a first power level and the second primary coil comprises two terminal ports defining the overall length of the second primary coil for application of alternating current to the second primary coil and is configured to deliver inductive power to a second type of portable device different from the first type of portable device at a second power level different from the first power level, and
wherein the first coil area and the second coil area overlap at least partially;

a first drive circuit, including a FET driver, a capacitor, and a FET switch, coupled to a DC voltage input and coupled to the first primary coil and the second primary coil, wherein when operating, the first drive circuit is configured to at any given time connect to the two terminal ports of a first selected primary coil, wherein the first selected primary coil is defined as only one of the first primary coil and the second primary coil, to directly apply an alternating current at the two terminal ports of a first selected primary coil at an operating frequency and duty cycle to generate an alternating magnetic field in a direction substantially perpendicular to the plane of the first selected primary coil and the surface to provide power inductively to the portable device when positioned on the surface;
a first sense circuit coupled to the first primary coil and the second primary coil to monitor current flow through the first selected primary coil to sense a signal corresponding to a current modulation in the first selected primary coil induced by modulation of current in the receiver coil of the portable device positioned on the surface; and
a communication and control circuit, including a microcontroller coupled to the first drive circuit and the first sense circuit, configured to:
detect, through the first sense circuit, a received communication of information in the current modulation in the first selected primary coil;
operate the first drive circuit to apply alternating current to inductively transfer power from the first selected primary coil to the receiver coil of the portable device positioned on the surface to activate and power the receiver circuit of the portable device positioned on the surface to enable the receiver circuit to communicate the received communication of information to the first selected primary coil to enable the communication and control circuit to configure the inductive transfer of power to the portable device positioned on the surface, wherein the received communication of information includes:
information corresponding to a voltage or current induced by the first selected primary coil at an output of the receiver circuit;
a unique identification code; and
a manufacturer code; and

select, based on the received communication of information, a second selected primary coil from one of the first primary coil and the second primary coil to charge the battery of the portable device positioned on the surface depending on the received communication of information, wherein the second selected primary coil can be different from the first selected primary coil;
operate the first drive circuit to apply alternating current to the second selected primary coil to receive additional information via the first sense circuit from the portable device positioned on the surface; and
according to the additional information, using closed-loop feedback regulation, provide power inductively from the second selected primary coil to the receiver coil to power the receiver circuit and charge the battery of the portable device positioned on the surface at the power level of the second selected primary coil.

2. The system of claim 1 , wherein the additional information includes information corresponding to the voltage or current at the output of the receiver circuit while charging the battery of the portable device positioned on the surface, and wherein, to charge the battery of the portable device positioned on the surface, the communication and control circuit is configured to:
regulate, using closed-loop feedback regulation, the voltage or current at the output of the receiver circuit in accordance with the received additional information by adjusting at least one of the operating frequency, the voltage at the DC voltage input, and the duty cycle of the first drive circuit while charging the battery of the portable device positioned on the surface; and
monitor for continued presence of the portable device positioned on the surface and completion of the charging of the battery of the portable device positioned on the surface based on the additional information from the receiver circuit detected by the communication and control circuit through the first sense circuit.

3. The system of claim 1 , wherein the closed-loop feedback regulation comprises a Proportional-Integral-Derivative (PID) control technique for regulating a voltage or current at the output of the receiver circuit.

4. The system of claim 2 , wherein the DC voltage input is configured to receive a DC voltage and the system further comprises:
a voltage regulator circuit coupled to the DC voltage input and to the microcontroller, wherein the microcontroller is configured to control the voltage regulator circuit to vary a level of the DC voltage between multiple values based on the received communication of information and the additional information received by the communication and control circuit through the first sense circuit.

5. The system of claim 1 , wherein the first drive circuit comprises a drive circuit for the first primary coil and a different drive circuit for the second primary coil, only one of which is operated at any given time.

6. The system of claim 1 , further comprising one or more coupling switches to couple one of the first primary coil and the second primary coil to the first drive circuit for providing power inductively to the portable device.

7. The system of claim 1 , wherein the communication and control circuit is further configured to operate the first drive circuit for a period of time to detect a current draw through one of the first primary coil and the second primary coil indicating a possible presence of the portable device positioned on the surface for charging, wherein the period of time is longer than that needed to activate and power the receiver circuit and for the communication and control circuit to detect information in the received communication corresponding to the voltage or current at the output of the receiver circuit in the portable device positioned on the surface.

8. The system of claim 1 , further comprising a high heat conductivity layer positioned proximate to the first primary coil and the second primary coil that covers at least an area surrounding the first primary coil and the se

Assignees

• Mojo Mobility Inc

Inventors

• Partovi Afshin
• Sears Michael

Classifications

• H02J2101/22

  Solar energy · CPC title

• H02J7/445

  in response to measured battery parameters, e.g. voltage, current or temperature profile · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title