SYSTEM AND METHOD FOR WIRELESS POWER TRANSFER

• US 20110084656A1
• Filed: 10/13/2009
• Published: 04/14/2011
• Est. Priority Date: 10/13/2009
• Status: Active Grant

• Current Assignee: Multi-Fineline Electronix Incorporated (Suzhou Dongshan Precision Manufacturing Company Limited)
• Original Assignee: Multi-Fineline Electronix Incorporated (Suzhou Dongshan Precision Manufacturing Company Limited)
• Inventors: Gao, Qiang
• Granted Patent: US 8,228,027 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 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 Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A wireless transmission system having a transmitter and receiver is described. In one embodiment, the transmitter includes an electronically-controlled switch controlled by a first pulse width modulation control circuit, the switch configured to pull current through a first inductor when the switch is closed, the first pulse width modulation control circuit outputting a PWM output signal to control the switch. A first feedback signal obtained from a control input of the switch. A second feedback signal obtained from a terminal of the inductor, wherein a control feedback signal is computed, at least in part, as a difference between the first feedback signal and the second feedback signal is provided to the first pulse width modulation control circuit. In one embodiment, the receiver includes a second pulse with modulation controller, the second pulse width modulation controller controlling the receiver switch to deliver a desired power from the receiving coil to a load.

Claims

1. An efficient power transmitter, comprising:

an electronically-controlled switch controlled by a first pulse width modulation control circuit, said switch configured to pull current through a first inductor when said switch is closed, said first pulse width modulation control circuit outputting a PWM output signal to control said switch;

a first feedback signal obtained from a control input of said switch; and

a second feedback signal obtained from a terminal of said inductor, wherein a control feedback signal is computed, at least in part, as a difference between said first feedback signal and said second feedback signal is provided to said first pulse width modulation control circuit, said control circuit adjusting a frequency of said PWM output signal, at least in part, in response to said control feedback.

2. The transmitter of claim 1, wherein said electronically-controlled switch comprises a MOSFET.

3. The transmitter of claim 1, further comprising an electronically-controlled delay line, said electronically-controlled delay line controlling a time delay of said control.

4. The transmitter of claim 1, wherein an output of said transmitter is provided to a transmitting coil.

5. The transmitter of claim 4, further comprising a filter that filters frequency components of voltages across said transmitting coil and provides a filtered signal to said first pulse width modulation control circuit.

6. An efficient wireless transmission system, comprising:

a transmitter, comprising;

an electronically-controlled switch controlled by a first pulse width modulation control circuit, said switch configured to pull current through a first inductor when said switch is closed, said first pulse width modulation control circuit outputting a PWM output signal to control said switch;

a first feedback signal obtained from a control input of said switch;

a transmitting coil;

a second feedback signal obtained from a terminal of said inductor, wherein a control feedback signal is computed, at least in part, as a difference between said first feedback signal and said second feedback signal is provided to said first pulse width modulation control circuit, said control circuit adjusting a frequency of said PWM output signal, at least in part, in response to said control feedback; and

a receiver, comprising;

a receiving coil provided to a receiver switch; and

a second pulse with modulation controller, said second pulse width modulation controller controlling said receiver switch to deliver a desired power from said receiving coil to a load.

7. The system of claim 6, wherein said electronically-controlled switch comprises a MOSFET.

8. The system of claim 6, further comprising an electronically-controlled delay line, said electronically-controlled delay line controlling a time delay of said control.

9. The transmitter of claim 6, further comprising a filter that filters frequency components corresponding to a switching frequency of said second pulse width modulation controller provides a filtered signal to said first pulse width modulation control circuit.

10. The system of claim 6, wherein said transmitting coil comprises a substantially flat conductor, said conductor comprising a series of holes/via spaced along a length of said conductor.

11. The system of claim 6, wherein said receiving coil comprises a substantially flat conductor, said conductor comprising a series of holes/via spaced along a length of said conductor.