DC/AC conversion apparatus and method having contactless, inductive energy transfer

• US 6,490,176 B2
• Filed: 06/06/2001
• Issued: 12/03/2002
• Est. Priority Date: 03/28/2001
• Status: Expired due to Fees

• Current Assignee: Provera GmbH
• Original Assignee: Provera GmbH
• Inventors: Holzer, Walter, Manukov, Rudolf
• Primary Examiner(s): Berhane, Adolf Deneke
• Application Number:
  US09/875,631
• Publication Number:
  US 20020141215A1
• Time in Patent Office: 545 Days
• Field of Search: 363/16, 363/17, 363/20, 363/21.01, 363/95, 363/98, 363/131, 363/132
• US Class Current: 363/20
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits

Abstract

A DC/AC converter is provided for contactless, inductive transfer of energy, which transfers arbitrary voltages to a removable user with the aid of a high-frequency pulse generator. The pulse generator produces asymmetric pulses, which provides two different voltages to the user, depending on a to coupling orientation. Further, the pulse generator is built in such a way that, if a user is absent, it is not excited to oscillation and, as a result, uses substantially no energy at all in a stand-by operation.

Claims

1. A DC/AC converter system having contactless, inductive energy transfer comprising:

an electronic high-frequency pulse generator including a first magnetic core coupled with a primary winding; and

a user circuit configured to inductively couple with the electronic high-frequency pulse generator without contact, the user circuit including a second magnetic core coupled with an associated secondary winding;

wherein the second magnetic core is configured to magnetically couple with the first magnetic core is at least two predetermined positions with respect to the first magnetic core and distinct corresponding prescribed levels of energy transfer result for each of the at least two predetermined positions.

2. The DC/AC converter system according to claim 1, wherein the at least two predetermined positions of the first magnetic core with respect to the second magnetic core coupled with the secondary winding differ substantially from each other by an angle of 180 degrees around one axis of rotation.

3. The DC/AC converter system according to claim 1, further comprising:

a housing that houses electronic high-frequency pulse generator;

one or more guide elements disposed on the housing that are configured to facilitate the at least two predetermined positions of the first magnetic core with respect to the second the magnetic core.

4. The DC/AC converter system according to claim 1, wherein the second magnetic core and secondary winding are detachable such that any one of a plurality of second magnetic cores each having a different corresponding secondary winding for contactless energy transfer may be attached in the user circuit.

5. The DC/AC converter system according to claim 4, wherein the one or more guide elements are configured to permit a limited rotation of the first magnetic core with respect to the second magnetic core around at least one axis of rotation.

6. The DC/AC converter system according to claim 1, further comprising:

the electronic pulse generator having the primary winding and a feedback winding respectively disposed on a corresponding outer pole of the first magnetic core, such that when the second magnetic core is removed, a leakage flux is produced between one of the two outer poles of the first magnetic core and a middle pole of the first magnetic core that decouples the primary coil and the feedback coil.

7. The DC/AC converter system according to claim 1, further comprising:

the electronic high-frequency pulse generator including a stand-by circuit comprised of a high-frequency filter circuit including a capacitor, a diode and a resistor that is configured to stabilize the stand-by circuit.

8. The DC/AC converter system according to claim 1, wherein the electronic high-frequency pulse generator is configured to generate pulses having a prescribed duty cycle.

9. The DC/AC converter system according to claim 8, wherein the prescribed duty cycle is an asymmetric duty cycle configured such that a first energy transfer level occurs when the first magnetic core is placed in a first position of the at least two predetermined positions relative to the second magnetic core and a second energy transfer level occurs when the first magnetic core is placed in a second position of the at least two predetermined positions relative to the second magnetic core.

10. The DC/AC converter system according to claim 1, further comprising:

the user circuit including a series connection of a load and half-wave rectifier;

wherein the series connection is connected in series with the secondary winding such that a DC/AC/DC converter system is produced.

11. The DC/AC converter system according to claim 10, wherein the load is a rechargeable battery that is charged by the DC/AC/DC converter system.

12. The DC/AC converter system according to claim 1, wherein the first magnetic core is E-shaped having at least three poles.

13. The DC/AC converter system according to claim 1, further comprising:

a sensing winding coupled to the first magnetic core that is configured to provide a rectangular pulse signal in the first magnetic core to a base terminal of a switching transistor that is used to effect the rectangular pulse signal.

14. A method of using a DC/AC converter system for contactless, inductive energy transfer, the method comprising:

providing an electronic high-frequency pulse generator including a first magnetic core coupled with a primary winding; and

providing a user circuit configured to inductively couple with the electronic high-frequency pulse generator without contact, the user circuit including a second magnetic core coupled with an associated secondary winding;

wherein the second magnetic core is configured to magnetically couple with the first magnetic core in at least two predetermined positions with respect to the first magnetic core and distinct corresponding prescribed levels of energy transfer result for each of the at least two predetermined positions.

15. The method according to claim 14, wherein the at least two predetermined positions of the first magnetic core with respect to the second magnetic core coupled with the secondary winding differ substantially from each other by an angle of 180 degrees around one axis of rotation.

16. The method according to claim 14, further comprising:

providing a housing that houses electronic high-frequency pulse generator; and

disposing one or more guide elements on the housing that are configured to facilitate the at least two predetermined positions of the first magnetic core with respect to the second the magnetic core.

17. The method according to claim 14, wherein the second magnetic core and secondary winding are detachable such that any one of a plurality of second magnetic cores each having a different corresponding secondary winding for contactless energy transfer may be attached in the user circuit.

18. The method according to claim 17, wherein the one or more guide elements are configured to permit a limited rotation of the first magnetic core with respect to the second magnetic core around at least one axis of rotation.

19. The method according to claim 14, further comprising:

respectively disposing the primary coil and a feedback coil on outer poles of the first magnetic core, such that when the second magnetic core is removed, a leakage flux is produced between one of the two outer poles of the first magnetic core and a middle pole of the first magnetic core that decouples the primary coil and the feedback coil.

20. The method according to claim 14, further comprising:

providing the electronic high-frequency pulse generator with a standby circuit comprised of a high-frequency filter circuit including a capacitor, a diode and a resistor that is configured to stabilize the stand-by circuit.

21. The method according to claim 14, further comprising:

generating pulses having a prescribed duty cycle using the electronic high-frequency pulse generator.

22. The method according to claim 21, wherein the prescribed duty cycle is an asymmetric duty cycle configured such that a first energy transfer level occurs when the first magnetic core is placed in a first position of the at least two predetermined positions relative to the second magnetic core and a second energy transfer level occurs when the first magnetic core is placed in a second position of the at least two predetermined positions relative to the second magnetic core.

23. The method according to claim 14, further comprising:

providing a series connection of a load and half-wave rectifier in the user circuit;

wherein the series connection is connected in series with the secondary winding such that a DC/AC/DC converter system is produced.

24. The method according to claim 23, wherein the load is a rechargeable battery that is charged by the DC/AC/DC converter system.

25. The method according to claim 22, wherein the first and second levels of energy transfer are fast and slower battery charging currents, respectively.

26. The method according to claim 14, wherein the first magnetic core is E-shaped having at least three poles.

27. The method according to claim 14, further comprising:

providing a sensing winding coupled to the first magnetic core that is configured to provide a rectangular pulse signal in the first magnetic core to a base terminal of a switching transistor that is used to effect the rectangular pulse signal.