Rechargeable Power Supply, Battery Device, Contactless Charger System And Method For Charging Rechargeable Battery Cell

• US 20080211455A1
• Filed: 07/10/2006
• Published: 09/04/2008
• Est. Priority Date: 07/30/2005
• Status: Active Grant

• Current Assignee: LS Cable And System Limited (LS Cable)
• Original Assignee: LS Cable Limited (LS Corporation)
• Inventors: Choi, Sung-Wook, Han, Sub, Park, Dong-Young, Gwon, Gwang-Hee, Moon, Sung-Wook, Kim, Jung-Bum
• Granted Patent: US 8,129,942 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

A system, method and apparatus for contact-less charging of battery operated devices is presented. There is a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC. The method obviates the need for a voltage controller in each of both the host and the portable stages, thus decreasing complexity and increasing efficiency. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. Two embodiments for the charging circuitry in the portable device are presented. In one embodiment component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment charging efficiency is maximized regardless of the output voltage of the battery, but additional components are utilized.

Claims

1. A charging power supply device contactlessly coupled with a battery device including a secondary coil for induced coupling, a wireless transmitting module for wirelessly transmitting data, a charging control circuit for controlling a charging status of a battery, and a rechargeable battery, the charging power supply device comprising:

a primary coil for inducing a charging power to the secondary coil;

a wireless receiving module for receiving charging status information from the wireless transmitting module; and

means for driving the primary coil so that a power signal between the primary and secondary coils and a communication signal between the wireless transmitting and receiving modules are not overlapped in aspect of time.

2. The charging power supply device according to claim 1,

wherein the charging power is a power pulse train made by modulating a pulse width of an AC voltage having a frequency larger than an AC line frequency.

3. The charging power supply device according to claim 2,

wherein the communication signal is synchronized to a falling edge of the power pulse.

4. The charging power supply device according to claim 1,

wherein the driving means analyzes the charging status information and controls a width of a power pulse for driving the primary coil.

5. The charging power supply device according to claim 4,

wherein the charging status information includes a charging start signal as well as a charging voltage and a charging current of the battery.

6. The charging power supply device according to claim 4, further comprising a rectifier for converting an AC line voltage into a DC voltage.

7. The charging power supply device according to claim 6, wherein the driving means includes:

a voltage converting means for generating an AC voltage having a frequency larger than an AC line frequency (60 Hz) using the DC voltage from the rectifier;

a pulse width modulator for generating a pulse width modulation signal to be applied to the primary coil by using the AC voltage; and

a controller for analyzing the charging status information and controlling the pulse width modulator based on the analysis result.

8. The charging power supply device according to claim 1, wherein the wireless receiving module includes:

an antenna for receiving a charging status signal from the wireless transmitting module; and

a demodulator for restoring charging status information from the charging status signal.

9. The charging power supply device according to claim 8,

wherein the antenna is arranged to surround the primary coil.

10. A charging device for receiving a power contactlessly from a charging power supply device that generates an AC voltage pulse having a frequency larger than an AC line frequency using an AC line voltage, and charging a rechargeable battery using the power, the charging device comprising:

a secondary coil magnetically coupled with a primary coil of the charging power supply device to generate an induced electromotive force pulse corresponding to the AC voltage pulse;

a charging control circuit for generating a constant voltage and a constant current used for charging the battery on the basis of the induced electromotive force pulse; and

a feedback control means for checking a falling edge of the induced electromotive force pulse, and then wirelessly feeding back a feedback response signal including charging status information of the battery to the charging power supply device in case a falling is detected.

11. The charging device according to claim 10, further comprising:

a monitoring circuit for monitoring a charging status of the battery to generate charging status information, and then storing the charging status information to a memory;

a memory for storing the charging status information and battery specification information; and

a wireless transmitting module for generating a feedback response signal based on the charging status information, and wirelessly transmitting the feedback response signal to the charging power supply device.

12. The charging device according to claim 10,

wherein the charging status information includes a charging voltage and a charging current of the battery.

13. The charging device according to claim 11,

wherein, in case there is no charging status information in the memory during the falling detecting step, the feedback control means generates a charging start signal requesting supply of a charging power, and then transmits the charging start signal to the wireless transmitting module as a feedback response signal.

14. The charging device according to claim 10, wherein the wireless transmitting module includes:

a modulator for modulating the feedback response signal; and

an antenna for sending the modulated feedback response signal.

15. The charging device according to claim 14,

wherein the antenna surrounds the secondary coil.

16. A battery device for contactlessly receiving a charging power from a power supply device that generates a pulse width modulation signal having a frequency larger than an AC line frequency using an AC line power, the battery device comprising:

a rechargeable battery;

a secondary coil magnetically coupled with a primary coil of the power supply device to generate an induced electromotive force pulse corresponding to the pulse width modulation signal;

a charging control circuit for generating a constant voltage and a constant current used for charging the battery on the basis of the induced electromotive force, and

charging the battery using the constant voltage and the constant current;

a falling detector for detecting a falling edge of the induced electromotive force pulse;

a memory for storing charging status information of the battery and battery specification information;

a monitoring circuit for monitoring a charging status of the battery to generate charging status information, and storing the charging status information to the memory;

a wireless transmitting module for modulating the charging status information to generate a feedback response signal, and wirelessly transmitting the feedback response signal to the power supply device; and

a feedback controller for reading the charging status information from the memory and transmitting the charging status information to the wireless transmitting module in case the falling edge is detected.

17. The battery device according to claim 16, further comprising a protection circuit for protecting the battery against an overcharging or an overcurrent.

18. The battery device according to claim 16,

wherein the charging status information includes a charging voltage and a charging current of the battery.

19. The battery device according to claim 16,

wherein, in case there is no charging status information in the memory, the feedback controller generates a charging start signal that requests supply of a charging power.

20. The battery device according to claim 16, further comprising a rectifier for converting the AC voltage generated by the secondary coil into a DC voltage.

21. The battery device according to claim 16, wherein the wireless transmitting module includes:

a modulator for modulating the feedback response signal; and

an antenna for sending the modulated feedback response signal.

22. The battery device according to claim 21,

wherein the antenna surrounds the secondary coil.

23. A method for charging a battery in a contactless charger system that includes a primary charging unit having a primary coil and a wireless receiving module, a secondary charging unit having a wireless transmitting module and a secondary coil magnetically coupled with the primary coil, and a battery for receiving a charging voltage from the second charging unit, the method comprising:

(A) applying a power pulse train having a pulse width (W₁) to the primary coil to emit out a corresponding magnetic field;

(B) wirelessly receiving from the secondary charging unit a charging start signal confirming that the primary coil and the secondary coil are magnetically coupled;

(C) generating a charging power pulse train having a pulse width (W₂) at least greater than the pulse width (W₁) according to the charging start signal, and applying the charging power pulse train to the primary coil to generate a corresponding induced electromotive force pulse to the secondary coil;

(D) charging the battery using the induced electromotive force pulse;

(E) feeding back the charging status information of the battery from the secondary charging unit; and

(F) controlling a pulse width of the charging power pulse based on the charging status information,

wherein the wireless feedback signal from the secondary charging unit is synchronized with a falling edge of the induced electromotive force pulse.

24. The method for charging a battery according to claim 23,

wherein, in the step (F), in case the battery is completely charged as a result of analysis of the charging status information, a pulse width (W₃) of the power pulse train applied to the primary coil is controlled smaller than W but equal to or greater than W₁.

25. The method for charging a battery according to claim 24,

wherein the pulse width (W₃) is equal to W₁.

26. The method for charging a battery according to claim 23, wherein the step (B) includes:

generating an induced electromotive force pulse from the secondary coil as the primary coil and the secondary coil are magnetically coupled;

checking a falling edge of the induced electromotive pulse and reading the charging status information from the memory;

determining a current status as an initial charging stage in case the charging status information is not recorded in the memory, and then generating an initial charging signal; and

transmitting the initial charging signal to the wireless receiving module of the primary charging unit via the wireless transmitting module.

27. The method for charging a battery according to claim 23,

wherein the power pulse train is generated by means of pulse width modulation of a high frequency AC voltage having a frequency larger than an AC line frequency.

28. The method for charging a battery according to claim 23,

wherein the charging status information at least includes a charging voltage value or a charging current value of the battery.

29. The method for charging a battery according to claim 23, wherein the step (A) includes:

rectifying an AC line voltage into a DC voltage;

generating an AC voltage having a frequency larger than an AC line frequency using the rectified DC;

modulating a pulse width of the AC voltage to generate a power pulse train having a pulse width (W₁); and

applying the power pulse train to the primary coil.

30. The method for charging a battery according to claim 23, wherein the step (D) includes:

rectifying the induced electromotive force (or, AC voltage) into a DC voltage;

generating a constant voltage and a constant current of a predetermined level, which is to be charged to the battery using the rectified DC voltage; and

charging the battery in a constant current mode until a battery voltage reaches a predetermined level, and charging the battery in a constant voltage mode by controlling an amount of a charging current in case the battery voltage reaches the level.

31. The method for charging a battery according to claim 23, wherein the step (E) includes:

checking a falling edge of the induced electromotive force pulse induced from the secondary coil;

reading the charging status information from the memory in case a falling edge is checked; and

generating a feedback response signal based on the charging status information and transmitting the feedback response signal to the wireless receiving module of the first charging unit through the wireless transmitting unit.

32. The method for charging a battery according to claim 23, wherein the step (F) includes:

analyzing the charging status information to determine whether the battery is completely charged; and

controlling a pulse width of the power pulse applied to the primary coil in correspondence to the charging status, in case the battery is not completely charged.

33. A contactless charger system including a primary charging unit having a primary coil and a wireless receiving module, a secondary charging unit having a wireless transmitting module and a secondary coil magnetically coupled with the primary coil, and a battery for receiving a charging voltage from the second charging unit,

wherein the primary charging unit includes means for generating an AC power pulse having a frequency larger than an AC line frequency as an AC line power is applied, and then applying the AC power pulse to the primary coil to induce a high frequency AC power pulse to the secondary coil,

wherein the secondary charging unit includes means for transmitting charging status information of the battery to the primary charging unit by using an unused time between pulses of the AC voltage pulse induced by the secondary coil, whereby a power signal between the primary and secondary coils and a communication signal between the wireless transmitting and receiving modules are not overlapped in aspect of time.

34. The contactless charger system according to claim 33,

wherein the transmitting means detects a falling edge of the induced electromotive force pulse and transmits the charging status information of the battery together with detection of the falling edge.

35. The contactless charger system according to claim 34, wherein the inducing means of the primary charging unit includes:

means for generating an AC voltage having a frequency larger than an AC line frequency based on a DC voltage obtained by rectifying the AC line power; and

means for generating a pulse width modulation signal using the AC voltage having a frequency larger than an AC line frequency.

36. The contactless charger system according to claim 35,

wherein the primary charging unit further includes means for analyzing the charging status information of the battery and controlling the pulse width.

37. The contactless charger system according to claim 34,

wherein the charging status information of the battery includes a charging voltage and a charging current of the battery.

38. The contactless charger system according to claim 34, wherein the second charging unit includes:

means for detecting a falling edge of the induced electromotive force pulse generated from the secondary coil; and

means for extracting the charging status information of the battery according to the detection of the falling edge, and generating a feedback response signal to be transmitted to the wireless receiving module of the primary charging unit using the charging status information.

39. The contactless charger system according to claim 38, wherein the second charging unit further includes:

means for rectifying the induced electromotive force generated from the secondary coil into a DC voltage; and

means for generating a constant voltage and a constant current to be supplied to the battery using the rectified DC voltage.

40. The contactless charger system according to claim 39, wherein the second charging unit further includes:

means for detecting a charging voltage and a charging current of the battery; and

means for storing the charging voltage and the charging current.