Circuit for transmitting an amplified resonant power to load

• US 8,077,485 B2
• Filed: 12/28/2006
• Issued: 12/13/2011
• Est. Priority Date: 12/29/2005
• Status: Expired due to Fees

• Current Assignee: Seoul National University of Technology Center for Industry Collaboration (Seoul National University)
• Original Assignee: Kwang-Jeek Lee
• Inventors: Lee, Kwang-Jeek
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US12/158,665
• Publication Number:
  US 20080297134A1
• Time in Patent Office: 1,811 Days
• Field of Search: 363/15, 363/16, 363/20, 363/21.02
• US Class Current: 363/21.02
• CPC Class Codes: H02M 5/08 using capacitors only
• CPC Class Codes: H02M 5/12 for conversion of voltage or current amplitude only
• CPC Class Codes: H02M 7/42 Conversion of dc power input into ac power output without possibility of reversal

Abstract

A circuit for transferring amplified resonant power to a load is disclosed. The circuit transfers amplified resonant power, which is generated in an inductor of a conventional transformer when serial or parallel resonance of a conventional power supply is formed, to a load through the conventional transformer. The circuit comprises: a power supply for producing and supplying voltage or current; a power amplifier for generating amplified resonant power using the voltage or current; and a power transferring unit for transferring the amplified resonant power to the load using a transformer.

Claims

1. A circuit for transferring amplified resonant power to a load, comprising:

a power supply for producing and supplying voltage or current;

a power amplifier for generating an amplified resonant power using the voltage or current; and

a power transferring unit for transferring the amplified resonant power to the load using a transformer, wherein a reflective impedance is adjusted and a resistance of the load is selected to maintain a resonance of a primary side of the power transferring unit.

2. The circuit according to claim 1, wherein the power supply is one of AC voltage source, AC current source, DC voltage source, and DC current source.

3. The circuit according to claim 1, wherein the power amplifier includes:

a primary inductor of the transformer; and

a capacitor connected to the primary inductor in serial or in parallel, wherein the amplified resonant power is stored in the primary inductor.

4. The circuit according to claim 1, wherein reflective impedance at the primary side of the transformer has a relatively small value such that the power amplifier can maintain resonance, wherein reflective resistance (R₂₁) of the reflective impedance (Z₂₁) is less than equivalent inductive reactance (XL₁) of the primary side of the transformer transferring the resonant power, and reflective reactance (X₂₁) is less than 0.5 of the equivalent inductive reactance (XL₁) of the primary side of the transformer.

5. The circuit according to claim 1, wherein the circuit amplifies power by using parallel resonance, and transfers the amplified resonant power to the load, such that power consumption of the load can be reduced.

6. The circuit of claim 1, wherein the power transferring unit has a coupling coefficient substantially equal to 1.

7. The circuit of claim 1, wherein a voltage under serial resonance at a secondary side of the power transferring unit equals

i k*V₁/n =k*Q*V_g/n =(Q/n)*k*V_g where

Q denotes a quality factor of the circuit, n denotes a turns ratio of the power transferring unit, k denotes a coupling coefficient, V_g denotes a source voltage, and V₁ denotes a voltage across an inductor in serial resonance.

8. The circuit of claim 1, wherein a smaller reflective impedance increases the amplified resonant power.

9. The circuit of claim 1, wherein the power supply is configured as a trigger to maintain a resonance.

10. The circuit of claim 1, wherein an increase in a load resistance decreases a reflective resistance and a reflective impedance but increases a quality factor of an inductor of a primary side of the power transferring unit.

11. The circuit of claim 1, wherein a power consumed by the load is determined by a voltage of a primary side of the power transferring unit and a current of the primary side of the power transferring unit.

12. A circuit comprising:

a power supply for supplying one of a voltage or a current wherein the power supply is configured as a trigger to maintain a resonance;

a power amplifier connected to the power supply, the power amplifier configured to generate an amplified resonant power using the one of the voltage and the current, wherein the amplified resonant power is associated with the resonance; and

a power transferring unit connected to the power amplifier, the power transferring unit configured to transfer the amplified resonant power to a load wherein the power transferring unit has a coupling coefficient substantially equal to 1 and an increase in a resistance of the load decreases a reflective resistance and a reflective impedance but increases a quality factor of an inductor of a primary side of the power transferring unit.

13. A circuit comprising:

a power supply for supplying one of a voltage or a current;

a power amplifier connected to the power supply, the power amplifier configured to generate an amplified resonant power using the one of the voltage and the current; and

a power transferring unit connected to the power amplifier, the power transferring unit configured to transfer the amplified resonant power to a load wherein a voltage under serial resonance at a secondary side of the power transferring unit equals

k* V₁/n =k*Q*V_g/n =(Q/n)*k*V_g where

Q denotes a quality factor of the circuit, n denotes a turns ratio of the power transferring unit, k denotes a coupling coefficient, V_g denotes a source voltage, and V₁ denotes a voltage across an inductor in serial resonance.