MAGNETIC RESONANCE TYPE WIRELESS CHARGING CIRCUIT

• US 20170149281A1
• Filed: 10/16/2015
• Published: 05/25/2017
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: LV, Xuewen
• Granted Patent: US 9,948,147 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries

Abstract

The present disclosure provides a magnetic resonance type wireless charging circuit, and belongs to the field of wireless charging technology. The magnetic resonance type wireless charging circuit comprises: a high frequency oscillation circuit configured to generate an initial oscillation signal; and a driving circuit configured to generate a transmission signal using the initial oscillation signal; wherein the driving circuit comprises one stage of driving sub-circuit or n stages of driving sub-circuits with (n−1) stages of Direct Current (DC) blocking circuits serially connected thereamong in an alternate manner, where n≧2 and n is an integer, and each stage of driving sub-circuit comprises a frequency doubling circuit and a first frequency selection circuit which are connected in series. In the present disclosure, the frequency of the initial oscillation signal generated by the high frequency oscillation circuit is doubled, so as to increase the frequency of the transmission signal and ensure a transmission distance of the transmission signal, thereby ensuring the effects of wireless charging. When the frequency of the transmission signal is required to reach a certain value, the requirements for switch transistors are reduced, and a wireless charging circuit with good effects can be achieved by using cheap switch transistors, thereby reducing production cost of the wireless charging circuit.

Claims

1. A magnetic resonance type wireless charging circuit, comprising:

a high frequency oscillation circuit configured to generate an initial oscillation signal; and

a driving circuit connected to the high frequency oscillation circuit and configured to generate a transmission signal using the initial oscillation signal,

wherein the driving circuit comprises one stage of driving sub-circuit, and the driving sub-circuit comprises a frequency doubling circuit and a first frequency selection circuit, which are connected in series.

2. The magnetic resonance type wireless charging circuit according to claim 1, wherein the first frequency selection circuit comprises a first capacitor and a first inductor, which are connected in parallel;

the first capacitor and the first inductor satisfy the following equation;

3. The magnetic resonance type wireless charging circuit according to claim 1, wherein

the first frequency selection circuit comprises a second capacitor, a second inductor and a DC cancellation circuit;

wherein the DC cancellation circuit is connected to the second capacitor and the second inductor respectively.

4. The magnetic resonance type wireless charging circuit according to claim 3, wherein the DC cancellation circuit comprises a transformer having two inputs connected to two terminals of the second capacitor respectively and two outputs connected to two terminals of the second inductor respectively.

5. The magnetic resonance type wireless charging circuit according to claim 4, wherein

the second capacitor, the second inductor and the transformer satisfy the following equation:

6. The magnetic resonance type wireless charging circuit according to claim 1, wherein the frequency doubling circuit comprises a first diode, a second diode, a third diode and a fourth diode, wherein the first diode has an anode connected to a cathode of the fourth diode and a cathode connected to a cathode of the second diode, the second diode has an anode connected to a cathode of the third diode, and the third diode has an anode connected to an anode of the fourth diode;

a connection point between the first diode and the second diode in the driving sub-circuit and a connection point between the third diode and the fourth diode in the driving sub-circuit are connected to the first frequency selection circuit included in the driving sub-circuit respectively;

a connection point between the first diode and the fourth diode in the the driving sub-circuit and a connection point between the second diode and the third diode in the driving sub-circuit are connected to the high frequency oscillation circuit respectively,

wherein the driving sub-circuit is connected in series with the high frequency oscillation circuit.

7. The magnetic resonance type wireless charging circuit according to claim 1, wherein the driving circuit further comprises:

a second frequency selection circuit connected in series between the high frequency oscillation circuit and the driving sub-circuit and configured to filter the initial oscillation signal.

8. The magnetic resonance type wireless charging circuit according to claim 7, wherein the second frequency selection circuit comprises a third inductor and a third capacitor, which are connected in series or in parallel

9. The magnetic resonance type wireless charging circuit according to claim 1, wherein the driving circuit further comprises:

a peak cancellation circuit connected to the driving sub-circuit and configured to cancel a peak in an output signal of the driving sub-circuit.

10. The magnetic resonance type wireless charging circuit according to claim 9, wherein the peak cancellation circuit comprises a fourth capacitor having one terminal connected to the driving sub-circuit and another terminal connected to the ground.

11. The magnetic resonance type wireless charging circuit according to claim 1, wherein the DC blocking circuit comprises a fifth capacitor.

12. The magnetic resonance type wireless charging circuit according to claim 8, wherein the third capacitor and the third inductor satisfy the following equation:

13. A magnetic resonance type wireless charging circuit, comprising:

a high frequency oscillation circuit configured to generate an initial oscillation signal; and

a driving circuit connected to the high frequency oscillation circuit and configured to generate a transmission signal using the initial oscillation signal,

wherein the driving circuit comprises n stages of driving sub-circuits with (n−

1) stages of Direct Current (DC) blocking circuits serially connected thereamong in an alternate manner, where n≧

2 and n is an integer, and the driving sub-circuit comprises a frequency doubling circuit and a first frequency selection circuit, which are connected in series.

14. The magnetic resonance type wireless charging circuit according to claim 13, wherein the first frequency selection circuit comprises a first capacitor and a first inductor, which are connected in parallel;

the first capacitor and the first inductor in an i^th stage of driving sub-circuit satisfy the following equation;

15. The magnetic resonance type wireless charging circuit according to claim 13, wherein the first frequency selection circuit in an n^th stage of driving sub-circuit comprises a second capacitor, a second inductor and a DC cancellation circuit, and the n^th stage of driving sub-circuit is an n^th driving sub-circuit connected in series with the high frequency oscillation circuit,

wherein the DC cancellation circuit is connected to the second capacitor and the second inductor respectively.

16. The magnetic resonance type wireless charging circuit according to claim 15, wherein the DC cancellation circuit comprises a transformer having two inputs connected to two terminals of the second capacitor respectively and two outputs connected to two terminals of the second inductor respectively.

17. The magnetic resonance type wireless charging circuit according to claim 16, wherein the second capacitor, the second inductor and the transformer satisfy the following equation:

18. The magnetic resonance type wireless charging circuit according to claim 13, wherein the frequency doubling circuit comprises a first diode, a second diode, a third diode and a fourth diode, wherein the first diode has an anode connected to the cathode of the fourth diode and the cathode connected to a cathode of the second diode, the second diode has an anode connected to a cathode of the third diode, and the third diode has an anode connected to an anode of the fourth diode;

a connection point between the first diode and the second diode in an i^th stage of driving sub-circuit and a connection point between the third diode and the fourth diode in the i^th stage of driving sub-circuit are connected to the first frequency selection circuit included in the i^th stage of driving sub-circuit;

a connection point between the first diode and the fourth diode in the i^th stage of driving sub-circuit and a connection point between the second diode and the third diode in the i^th stage of driving sub-circuit are connected to a first frequency selection circuit included in an (i−

1)^th stage of driving sub-circuit respectively,

wherein the i^th stage of driving sub-circuit is an i^th driving sub-circuit connected in series with the high frequency oscillation circuit, wherein 2≦

i≦

n and I is an integer.

19. The magnetic resonance type wireless charging circuit according to claim 13, wherein the driving circuit further comprises:

a second frequency selection circuit connected in series between the high frequency oscillation circuit and the driving sub-circuit and configured to filter the initial oscillation signal.

20. The magnetic resonance type wireless charging circuit according to claim 19, wherein the second frequency selection circuit comprises a third inductor and a third capacitor, which are connected in series or in parallel.

21. The magnetic resonance type wireless charging circuit according to claim 20, wherein the third capacitor and the third inductor satisfy the following equation:

22. The magnetic resonance type wireless charging circuit according to claim 13, wherein the driving circuit further comprises:

a peak cancellation circuit connected to the driving sub-circuit and configured to cancel a peak in an output signal of the driving sub-circuit.

23. The magnetic resonance type wireless charging circuit according to claim 22, wherein the peak cancellation circuit comprises a fourth capacitor having one terminal connected to the driving sub-circuit and another terminal connected to the ground.

24. The magnetic resonance type wireless charging circuit according to claim 13, wherein the DC blocking circuit comprises a fifth capacitor.