Wireless power transfer using separately tunable resonators

• US 8,933,589 B2
• Filed: 02/07/2012
• Issued: 01/13/2015
• Est. Priority Date: 02/07/2012
• Status: Active Grant

• Current Assignee: Duracell U.S. Operations, Inc. (Berkshire Hathaway Incorporated)
• Original Assignee: Gillette Company (The Procter & Gamble Company)
• Inventors: Bourilkov, Jordan T., Specht, Steven J., Coronado-Hortal, Sergio
• Primary Examiner(s): Deberadinis, Robert L.
• Application Number:
  US13/367,443
• Publication Number:
  US 20130200717A1
• Time in Patent Office: 1,071 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

A system for wireless energy transfer includes a circuit for wireless transmission of energy, including a first, tunable resonator circuit including a transmitter coil and a variable capacitance device connected in shunt across the transmitter coil. Also disclosed is a circuit for wireless reception of energy including a tunable second resonator circuit including a receiver coil inductively coupled to the transmitter coil and a variable capacitance device connected in shunt across the receiver coil. Also disclosed is an arrangement for wireless energy transmission and reception that foregoes the necessity for separate circuits for DC rectification at the reception end of the arrangement. Also disclosed a system for wireless energy transfer where the system includes a tunable resonator circuit embedded in a surface such as piece of furniture, counter, etc., e.g., a table.

Claims

1. A system for wireless energy transfer, the system comprises:

a circuit for wireless transmission of energy, configured to be fed by an RF source the circuit for wireless transmission comprising;

a first resonator circuit;

a circuit for wireless reception of energy, from the first resonator circuit, the circuit for wireless reception comprising;

a second resonator circuit; and

a circuit disposed between the circuit for wireless transmission of energy and the circuit for wireless reception of energy to inductively couple with the first and second resonator circuits to effectively produce a rectified voltage having a DC component at the circuit for wireless reception of energy;

wherein the circuit to inductively couple comprises;

a magnetic field transmitter operating at the first harmonic or higher harmonic of the base transmitter frequency.

2. The circuit of claim 1 wherein the circuit to inductively couple comprises:

a tunable passive resonator disposed between the first and second resonator circuits, the tunable passive resonator comprising;

a coil having a large number of windings N1;

a variable capacitance device connected in shunt across the coil with the coil and the variable capacitor and intrinsic capacitance of the coil forming the tunable resonator circuit, with the first and second resonator circuits in combination with the passive tunable resonator circuit providing at an output of the second resonator circuit a voltage having a DC component.

3. The circuit of claim 1 wherein the first resonator further comprises:

a transmitter coil having a large number of windings N1;

a variable capacitance device connected in shunt across the transmitter coil with the transmitter coil and the variable capacitor and intrinsic capacitance of the transmitter coil forming the resonator circuit;

an input coil configured to be coupled to an input RF source, with the input coil having a low number of windings N2 compared to the number of windings N1 of the transmitter coil, and the input coil being inductively coupled to the transmitter coil to provide power output from the resonator circuit at a resonant frequency in a range of about 100 kHz to 30 MHz.

4. The circuit of claim 1 wherein the second resonator further comprises:

a receiver coil inductively coupled to the transmitter coil, the receiver coil having a large number of windings N3;

a variable capacitance device connected in shunt across the receiver coil with the receiver coil and the variable capacitor and intrinsic capacitance of the receiver coil forming the second resonator circuit;

an output coil with a low number of windings N2 compared to the number of windings N1 of the receiver coil, the output coil being inductively coupled to the receiver coil to provide power output from the circuit, with the resonator circuit having a resonant frequency in a range of about 100 kHz to 30 MHz.