WIRELESS POWER TRANSFER USING SEPARATELY TUNABLE RESONATORS

• US 20150084429A1
• Filed: 11/24/2014
• Published: 03/26/2015
• 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 Todorov, Specht, Steven Jeffrey, Coronado Hortal, Sergio
• Granted Patent: US 9,634,495 B2
• Time in Patent Office: Days
• 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 circuit comprising:

a resonator circuit for wireless reception of energy, comprising;

a receiver coil having a large number of windings N1;

a variable capacitance device connect in shunt across the receiver coil with the receiver coil and the variable capacitor and intrinsic capacitance of the receiver coil forming the 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.

2. The circuit of claim 1 wherein the resonator circuit is tuned by the variable capacitance device to a resonant frequency within the range of 100 kHz to 30 MHz.

3. The circuit of claim 1 wherein the resonator circuit oscillates at high voltage and produces a strong magnetic field that is coupled to the secondary coil.

4. The circuit of claim 1 wherein inductive coupling of the two coils produces an output voltage at the output coil related to V_L(coil)=V_in*Q*N2/N1.

5. The circuit of claim 1 further comprising:

circuitry to convert an AC voltage across the output coil to a DC voltage.

6. The circuit of claim 1 further comprising:

circuitry to convert an AC voltage across the output coil to a DC voltage, the circuitry comprising;

a capacitor connected in shunt across the secondary coil; and

a DC/DC converter or battery charger coupled to the capacitor.

7. The circuit of claim 1 further comprising:

a rectifier circuit connected to the output coil to convert AC voltage across the output coil to a DC voltage, the circuitry further comprising;

a capacitor connected in shunt across the secondary coil; and

a DC/DC converter coupled with the capacitor.

8. A circuit comprising:

a resonator circuit for wireless transmission of energy, the circuit comprising;

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 circuit with the resonator circuit having a resonant frequency in a range of about 100 kHz to 30 MHz.

9. The circuit of claim 8 wherein the resonator circuit is tuned by the variable capacitance device.

10. The circuit of claim 8 wherein the resonator circuit oscillates at high voltage and produces a strong magnetic field at the transmitter coil.

11. The circuit of claim 8 further comprising an RF source connected to the input coil.

12. The circuit of claim 8 wherein inductive coupling of the transmitter and input coils produces an output voltage at the transmitter coil related to V_L(coil)=V_in*Q*N1/N2 where V_m is related to the voltage of the RF source connected to the input coil.

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

a circuit for wireless transmission of energy, the circuit comprises;

a first resonator circuit comprising;

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 connected 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;

a circuit for wireless reception of energy, the circuit comprises;

a second resonator circuit comprising;

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.

14. The circuit of claim 13 wherein the second resonator circuit is tuned by the variable capacitance device to a resonant frequency within the range of 100 kHz to 30 MHz.

15. The circuit of claim 13 further comprising:

circuitry to convert an AC voltage across the output coil to a DC voltage.

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

a table;

a circuit embedded in the table for wireless transmission of energy, the circuit comprises;

a first resonator circuit comprising;

a transmitter conductor;

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

17. The circuit of claim 16 wherein the transmitter conductor is coupled to an input RF source to provide power output from the resonator circuit at a resonant frequency in a range of about 100 kHz to 30 MHz.