WIRELESS CHARGING CIRCUIT FOR POWER BANK AND POWER BANK THEREOF

• US 20150188355A1
• Filed: 09/05/2014
• Published: 07/02/2015
• Est. Priority Date: 12/27/2013
• Status: Active Grant

• Current Assignee: Generalplus Technology Inc.
• Original Assignee: Generalplus Technology Inc.
• Inventors: CHUANG, Down Xu
• Granted Patent: US 9,467,004 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence

Abstract

A wireless charging circuit for power bank and a power bank thereof are provided in the present invention. The wireless charging circuit includes a boost DC to DC converter, a unidirectional conductive element and a wireless power converter. The input terminal of the boost DC to DC converter is coupled to the battery to receive the battery voltage. The output terminal of the boost DC to DC converter outputs a converted DC voltage. The first terminal of the unidirectional conductive element is coupled to the battery to receive the battery voltage, wherein the direction of the current flow is from the first terminal of the unidirectional conductive element to the second terminal of the unidirectional conductive element. The input terminal of the wireless power converter is coupled to the second terminal of the unidirectional conductive element. When the wireless charging circuit performs the detection for the wireless power receiver, the wireless power converter disables the boost DC to DC converter.

Claims

1. A wireless charging circuit, adapted for a power bank, wherein the power bank comprises a battery, wherein the wireless charging circuit comprises:

a boost DC to DC converter, comprising an input terminal and an output terminal, wherein the input terminal of the boost DC to DC converter is coupled to the battery to receive a battery voltage, wherein the output terminal of the boost DC to DC converter is for outputting a converted DC voltage;

a unidirectional conductive element, comprising a first terminal and a second terminal, wherein the first terminal of the unidirectional conductive element is coupled to the battery to receive the battery voltage, wherein a current direction is from the first terminal of the unidirectional conductive element to the second terminal of the unidirectional conductive element; and

a wireless power converter, coupled to the second terminal of the unidirectional conductive element and the output terminal of the boost DC to DC converter,

wherein the wireless power converter disables the boost DC to DC converter when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not,

wherein the wireless power converter enables the boost DC to DC converter when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

2. The wireless charging circuit according to claim 1, wherein the boost DC to DC converter comprises an enable terminal, and the wireless power converter comprises:

a low voltage pulse width modulation (PWM) circuit, comprising an input terminal and an output terminal, wherein the input terminal of the low voltage PWM circuit is coupled to the second terminal of the unidirectional conductive element, and the output terminal of the low voltage PWM circuit outputs a PWM detecting signal;

a resonant circuit, comprising a first input terminal, wherein the first input terminal is coupled to the output terminal of the low voltage PWM circuit; and

a control circuit, coupled to the enable terminal of the boost DC to DC converter;

wherein, the control circuit controls the boost DC to DC converter to disable the boost DC to DC converter when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not.

3. The wireless charging circuit according to claim 2, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the first input terminal of the resonant circuit; and

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the second terminal of the resonant coil, and the second terminal of the resonant capacitor is coupled to the second input terminal of the resonant circuit.

4. The wireless charging circuit according to claim 2, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the first input terminal of the resonant circuit; and

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the second terminal of the resonant capacitor, and the second terminal of the resonant coil is coupled to the second input terminal of the resonant circuit.

5. The wireless charging circuit according to claim 2, wherein the low power PWM circuit comprises:

a first upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first upper switch is coupled to the control circuit, and the first terminal of the first upper switch is coupled to the second terminal of the unidirectional conductive element; and

a first lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first lower switch is coupled to the control circuit, the first terminal of the first lower switch is coupled to the second terminal of the first upper switch and the first input terminal of the resonant circuit, and the second terminal of the first lower switch is coupled to a common voltage.

6. The wireless charging circuit according to claim 2, further comprising:

a high voltage pulse width modulation (PWM) circuit, coupled to the output terminal of the boost DC to DC converter for outputting a driving PWM signal to the resonant circuit; and

a driving circuit, coupled to the high voltage pulse width modulation circuit, the boost DC to DC converter and the control circuit,

wherein the control circuit enables the boost DC to DC converter and the control circuit enables the driving circuit to drive the high voltage PWM circuit when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

7. The wireless charging circuit according to claim 6, wherein the high voltage PWM circuit comprises:

a second upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second upper switch is coupled to the driving circuit, and the first terminal of the second upper switch is coupled to the output terminal of the boost DC to DC converter; and

a second lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second lower switch is coupled to the driving circuit, the first terminal of the second lower switch is coupled to the second terminal of the second upper switch and the first input terminal of the resonant circuit, and the second terminal of the second lower switch is coupled to a common voltage.

8. The wireless charging circuit according to claim 7, wherein the resonant circuit further comprises a second input terminal, and high voltage PWM circuit further comprises:

a third upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third upper switch is coupled to the driving circuit, and the first terminal of the third upper switch is coupled to the output terminal of the boost DC to DC converter; and

a third lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third lower switch is coupled to the driving circuit, the first terminal of the third lower switch is coupled to the second terminal of the third upper switch and the second input terminal of the resonant circuit, and the second terminal of the third lower switch is coupled to the common voltage.

9. The wireless charging circuit according to claim 8, further comprising:

a detection switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the detection switch is coupled to the control circuit, the first terminal of the detection switch is coupled to the second input terminal of the resonant circuit, and the second terminal of the detection switch is coupled to the common voltage,

wherein the control circuit controls the detection switch to connect the first terminal of the detection switch with the second terminal of the detection switch when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not.

10. A mobile power bank, comprising:

a battery; and

a wireless charging circuit, comprising;

a boost DC to DC converter, comprising an input terminal and an output terminal, wherein the input terminal of the boost DC to DC converter is coupled to the battery to receive a battery voltage, wherein the output terminal of the boost DC to DC converter is for outputting a converted DC voltage;

a unidirectional conductive element, comprising a first terminal and a second terminal, wherein the first terminal of the unidirectional conductive element is coupled to the battery to receive the battery voltage, wherein a current direction is from the first terminal of the unidirectional conductive element to the second terminal of the unidirectional conductive element; and

a wireless power converter, coupled to the second terminal of the unidirectional conductive element and the output terminal of the boost DC to DC converter,

wherein the wireless power converter disables the boost DC to DC converter when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not,

wherein the wireless power converter enables the boost DC to DC converter when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

11. The mobile power bank according to claim 10, wherein the boost DC to DC converter comprises an enable terminal, and the wireless power converter comprises:

a low voltage pulse width modulation (PWM) circuit, comprising an input terminal and an output terminal, wherein the input terminal of the low voltage PWM circuit is coupled to the second terminal of the unidirectional conductive element, and the output terminal of the low voltage PWM circuit outputs a PWM detecting signal;

a resonant circuit, comprising a first input terminal, wherein the first input terminal is coupled to the output terminal of the low voltage PWM circuit; and

a control circuit, coupled to the enable terminal of the boost DC to DC converter;

wherein, the control circuit controls the boost DC to DC converter to disable the boost DC to DC converter when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not.

12. The mobile power bank according to claim 11, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the first input terminal of the resonant circuit; and

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the second terminal of the resonant coil, and the second terminal of the resonant capacitor is coupled to the second input terminal of the resonant circuit.

13. The mobile power bank according to claim 11, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the first input terminal of the resonant circuit; and

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the second terminal of the resonant capacitor, and the second terminal of the resonant coil is coupled to the second input terminal of the resonant circuit.

14. The mobile power bank according to claim 11, wherein the low power PWM circuit comprises:

a first upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first upper switch is coupled to the control circuit, and the first terminal of the first upper switch is coupled to the second terminal of the unidirectional conductive element; and

a first lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first lower switch is coupled to the control circuit, the first terminal of the first lower switch is coupled to the second terminal of the first upper switch and the first input terminal of the resonant circuit, and the second terminal of the first lower switch is coupled to a common voltage.

15. The mobile power bank according to claim 11, further comprising:

a high voltage pulse width modulation (PWM) circuit, coupled to the output terminal of the boost DC to DC converter for outputting a driving PWM signal to the resonant circuit; and

a driving circuit, coupled to the high voltage pulse width modulation circuit, the boost DC to DC converter and the control circuit,

wherein the control circuit enables the boost DC to DC converter and the control circuit enables the driving circuit to drive the high voltage PWM circuit when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

16. The mobile power bank according to claim 15, wherein the high voltage PWM circuit comprises:

a second upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second upper switch is coupled to the driving circuit, and the first terminal of the second upper switch is coupled to the output terminal of the boost DC to DC converter; and

a second lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second lower switch is coupled to the driving circuit, the first terminal of the second lower switch is coupled to the second terminal of the second upper switch and the first input terminal of the resonant circuit, and the second terminal of the second lower switch is coupled to a common voltage.

17. The mobile power bank according to claim 16, wherein the resonant circuit further comprises a second input terminal, and high voltage PWM circuit further comprises:

a third upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third upper switch is coupled to the driving circuit, and the first terminal of the third upper switch is coupled to the output terminal of the boost DC to DC converter; and

a third lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third lower switch is coupled to the driving circuit, the first terminal of the third lower switch is coupled to the second terminal of the third upper switch and the second input terminal of the resonant circuit, and the second terminal of the third lower switch is coupled to the common voltage.

18. The mobile power bank according to claim 17, further comprising:

a detection switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the detection switch is coupled to the control circuit, the first terminal of the detection switch is coupled to the second input terminal of the resonant circuit, and the second terminal of the detection switch is coupled to the common voltage,

wherein the control circuit controls the detection switch to connect the first terminal of the detection switch with the second terminal of the detection switch when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not.

19. A wireless charging circuit, adapted for a power bank, wherein the power bank comprises a battery, wherein the wireless charging circuit comprises:

a boost DC to DC converter, comprising an input terminal and an output terminal, wherein the input terminal of the boost DC to DC converter is coupled to the battery to receive a battery voltage, wherein the output terminal of the boost DC to DC converter is for outputting a converted DC voltage;

a control circuit, coupled to the battery to receive the battery voltage;

a low voltage pulse width modulation (PWM) circuit, coupled to the control circuit and the battery to receive the battery voltage, for outputting a low voltage PWM signal according to the control of the control circuit;

a wireless power converter, comprising;

a high voltage PWM circuit, coupled to the control circuit and the output terminal of the boost DC to DC converter, for outputting a high voltage PWM signal according to the control of the control circuit; and

a resonant circuit, comprising a first input terminal, wherein the first input terminal of the resonant circuit is coupled to the low voltage PWM circuit and a high voltage PWM circuit;

wherein the wireless power converter disables the boost DC to DC converter and the high voltage PWM circuit and the wireless power converter controls the low voltage PWM circuit to output the low voltage PWM signal to the resonant circuit when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not,

wherein the wireless power converter enables the boost DC to DC converter and the high voltage PWM circuit and the wireless power converter disables the low voltage PWM circuit when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

20. The wireless charging circuit according to claim 19, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the first input terminal of the resonant circuit; and

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the second terminal of the resonant coil, and the second terminal of the resonant capacitor is coupled to the second input terminal of the resonant circuit.

21. The wireless charging circuit according to claim 19, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the first input terminal of the resonant circuit; and

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the second terminal of the resonant capacitor, and the second terminal of the resonant coil is coupled to the second input terminal of the resonant circuit.

22. The wireless charging circuit according to claim 19, wherein the low power PWM circuit comprises:

a first upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first upper switch is coupled to the control circuit, and the first terminal of the first upper switch is coupled to the battery to receive the battery voltage; and

a first lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first lower switch is coupled to the control circuit, the first terminal of the first lower switch is coupled to the second terminal of the first upper switch and the first input terminal of the resonant circuit, and the second terminal of the first lower switch is coupled to a common voltage.

23. The wireless charging circuit according to claim 19, further comprising:

a driving circuit, coupled to the high voltage pulse width modulation circuit, the boost DC to DC converter and the control circuit,

wherein the control circuit enables the boost DC to DC converter and the control circuit enables the driving circuit to drive the high voltage PWM circuit when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

24. The wireless charging circuit according to claim 23, wherein the high voltage PWM circuit comprises:

a second upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second upper switch is coupled to the driving circuit, and the first terminal of the second upper switch is coupled to the output terminal of the boost DC to DC converter; and

a second lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second lower switch is coupled to the driving circuit, the first terminal of the second lower switch is coupled to the second terminal of the second upper switch and the first input terminal of the resonant circuit, and the second terminal of the second lower switch is coupled to a common voltage.

25. The wireless charging circuit according to claim 24, wherein the resonant circuit further comprises a second input terminal, and high voltage PWM circuit further comprises:

a third upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third upper switch is coupled to the driving circuit, and the first terminal of the third upper switch is coupled to the output terminal of the boost DC to DC converter; and

a third lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third lower switch is coupled to the driving circuit, the first terminal of the third lower switch is coupled to the second terminal of the third upper switch and the second input terminal of the resonant circuit, and the second terminal of the third lower switch is coupled to the common voltage.

26. The wireless charging circuit according to claim 25, further comprising:

a detection switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the detection switch is coupled to the control circuit, the first terminal of the detection switch is coupled to the second input terminal of the resonant circuit, and the second terminal of the detection switch is coupled to the common voltage,

wherein the control circuit controls the detection switch to connect the first terminal of the detection switch with the second terminal of the detection switch when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not.

27. A mobile power bank, comprising:

a battery; and

a wireless charging circuit, comprising;

a boost DC to DC converter, comprising an input terminal and an output terminal, wherein the input terminal of the boost DC to DC converter is coupled to the battery to receive a battery voltage, wherein the output terminal of the boost DC to DC converter is for outputting a converted DC voltage;

a control circuit, coupled to the battery to receive the battery voltage;

a low voltage pulse width modulation (PWM) circuit, coupled to the control circuit and the battery to receive the battery voltage, for outputting a low voltage PWM signal according to the control of the control circuit;

a wireless power converter, comprising;

a high voltage PWM circuit, coupled to the control circuit and the output terminal of the boost DC to DC converter, for outputting a high voltage PWM signal according to the control of the control circuit; and

a resonant circuit, comprising a first input terminal, wherein the first input terminal of the resonant circuit is coupled to the low voltage PWM circuit and a high voltage PWM circuit;

wherein the wireless power converter disables the boost DC to DC converter and the high voltage PWM circuit and the wireless power converter controls the low voltage PWM circuit to output the low voltage PWM signal to the resonant circuit when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not,

wherein the wireless power converter enables the boost DC to DC converter and the high voltage PWM circuit and the wireless power converter disables the low voltage PWM circuit when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

28. The mobile power bank according to claim 27, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the first input terminal of the resonant circuit; and

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the second terminal of the resonant coil, and the second terminal of the resonant capacitor is coupled to the second input terminal of the resonant circuit.

29. The mobile power bank according to claim 27, wherein the resonant circuit further comprises a second input terminal, and the resonant circuit comprises:

a resonant capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the resonant capacitor is coupled to the first input terminal of the resonant circuit; and

a resonant coil, comprising a first terminal and a second terminal, wherein the first terminal of the resonant coil is coupled to the second terminal of the resonant capacitor, and the second terminal of the resonant coil is coupled to the second input terminal of the resonant circuit.

30. The mobile power bank according to claim 27, wherein the low power PWM circuit comprises:

a first upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first upper switch is coupled to the control circuit, and the first terminal of the first upper switch is coupled to the battery to receive the battery voltage; and

a first lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the first lower switch is coupled to the control circuit, the first terminal of the first lower switch is coupled to the second terminal of the first upper switch and the first input terminal of the resonant circuit, and the second terminal of the first lower switch is coupled to a common voltage.

31. The mobile power bank according to claim 27, further comprising:

a driving circuit, coupled to the high voltage pulse width modulation circuit, the boost DC to DC converter and the control circuit,

wherein the control circuit enables the boost DC to DC converter and the control circuit enables the driving circuit to drive the high voltage PWM circuit when the wireless charging circuit determines that an external object is disposed on the wireless power converter.

32. The mobile power bank according to claim 31, wherein the high voltage PWM circuit comprises:

a second upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second upper switch is coupled to the driving circuit, and the first terminal of the second upper switch is coupled to the output terminal of the boost DC to DC converter; and

a second lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the second lower switch is coupled to the driving circuit, the first terminal of the second lower switch is coupled to the second terminal of the second upper switch and the first input terminal of the resonant circuit, and the second terminal of the second lower switch is coupled to a common voltage.

33. The mobile power bank according to claim 32, wherein the resonant circuit further comprises a second input terminal, and high voltage PWM circuit further comprises:

a third upper switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third upper switch is coupled to the driving circuit, and the first terminal of the third upper switch is coupled to the output terminal of the boost DC to DC converter; and

a third lower switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the third lower switch is coupled to the driving circuit, the first terminal of the third lower switch is coupled to the second terminal of the third upper switch and the second input terminal of the resonant circuit, and the second terminal of the third lower switch is coupled to the common voltage.

34. The mobile power bank according to claim 33, further comprising:

a detection switch, comprising a first terminal, a second terminal and a control terminal, wherein the control terminal of the detection switch is coupled to the control circuit, the first terminal of the detection switch is coupled to the second input terminal of the resonant circuit, and the second terminal of the detection switch is coupled to the common voltage,

wherein the control circuit controls the detection switch to connect the first terminal of the detection switch with the second terminal of the detection switch when the wireless charging circuit determines whether an external object is disposed on the wireless power converter or not.