KR100903461B1 - Wireless Charger and Battery charging set having the same - Google Patents

Abstract

The present invention relates to a charger and a battery charging set capable of charging a battery by a non-contact using an electromagnetic induction phenomenon. More particularly, the charging power can be controlled by sensing a state of a battery in a charger transmitting wireless power. To a charger and a battery charge set. The contactless charger according to the present invention includes a magnetic field generator for receiving an AC current to form a magnetic field in the external space; A high frequency power driver for applying a high frequency AC current to the magnetic field generating unit; A current detector detecting a current value applied to the magnetic field generator; And a charging power controller which receives the detection result from the current detector and controls the high frequency power driver to control the power of the high frequency AC current applied to the magnetic field generator.

Contactless, Charger, Current Limiting

Description

Contactless charger and battery charging set having same {Wireless Charger and Battery charging set having the same}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 schematically shows a configuration of a battery and a charger employing a contactless charging method according to the prior art.

2 is a block diagram schematically showing the configuration of a contactless charger (C) and a battery (B) according to a preferred embodiment of the present invention.

3 is a diagram illustrating a change in the current value measured by the current detector according to a preferred embodiment of the present invention.

4 is a diagram illustrating a change in the charging current and the charging voltage of the battery cell according to a preferred embodiment of the present invention.

5 is a block diagram showing in more detail the configuration of a contactless charger (C) according to an embodiment of the present invention.

<Description of main reference numerals in the drawings>

C ... No contact charger B ... No battery

200 ... primary coil 210 ... high frequency power drive

220 ... current detector 230 ... microprocessor

240 ... Power Supply 250 ... AC Power Supply

260 ... secondary coil 270 ... rectifier

280 ... constant voltage / constant supply 300 ... battery cell

The present invention relates to a charger and a battery charging set capable of charging a battery by a non-contact using an electromagnetic induction phenomenon. More particularly, the charging power can be controlled by sensing a state of a battery in a charger transmitting wireless power. To a charger and a battery charge set.

Personal portable devices such as mobile phones, PDAs, notebooks, etc., are powered by rechargeable batteries. When the user of the personal portable device falls below a predetermined level, the user of the portable device charges the battery using a charger and then uses the battery again.

A battery of a general personal portable device has an externally exposed connection terminal to be electrically connected to a charging terminal provided in a charger. When the battery is charged, the charging terminal of the charger and the connection terminal of the battery are connected to each other to maintain an electrically connected state.

However, since the charging terminal and the connection terminal are exposed to the outside for mutual connection, they are easily contaminated by foreign substances, and wear occurs due to friction between both terminals in the process of connecting the charging terminal and the connection terminal, and moisture in the air. This causes a problem that the connection between the charging terminal and the connection terminal becomes poor due to corrosion of the charging terminal and the connection terminal. If moisture penetrates into the battery through the minute gap of the connection terminal during the use of the battery, a fatal problem of completely discharging the battery is caused by a short circuit of the internal circuit.

In order to solve this problem, a contactless charging technology has recently been proposed to charge a battery in a state where a battery of a personal portable device is coupled with a charger in a contactless manner by an electromagnetic induction phenomenon. Contactless charging technology is now widely used in everyday products such as electric toothbrushes and electric shavers.

1 schematically shows a configuration of a battery and a charger employing a contactless charging method according to the prior art.

Referring to FIG. 1, the charger 10 receives a high frequency AC current from the commercial AC power supply 20 and outputs a high frequency AC current, and receives a high frequency AC current from the high frequency generator 30. The primary side coil 40 which forms M, and the drive control part 35 which control drive of the high frequency generation means 30 are provided.

In addition, the battery 50 may include a battery cell 60 in which electrical energy is charged, a secondary side coil 70 in which a high frequency alternating current is induced according to a linkage of the magnetic field M generated in the primary side coil 40, and a secondary side. Rectifier 80 for converting the high frequency AC current induced in the coil 70 to a DC current, a constant voltage / constant current supply unit 90 for applying the DC current rectified in the rectifier 80 to the battery cell 60, and the battery The charging detector 95 detects a voltage or a current applied to the cell 60.

Here, the constant voltage / constant current supply unit 90 is a known circuit element widely used in a battery charging device. The constant voltage / constant current supply unit 90 supplies a constant current to the battery cell 60 at the initial stage of charging, but gradually increases the charging voltage of the battery cell 60 to reduce the supply of current when the voltage exceeds the predetermined reference value. It keeps the function constant.

In addition, the charge detection unit 95 detects the current and voltage of the constant voltage / constant current supply unit 90 and the battery cell 60 and transmits the same to the drive control unit 35. The drive control unit 35 uses the battery cell ( The charging state of the control unit 60 is checked to control the driving of the high frequency generating unit 30.

The battery 50 having the charge detector 95 is mounted in a personal portable device such as a mobile phone or a PDA. The battery 50 is increased by increasing the volume of the entire battery 50 to provide the charge detector 95. Difficult to miniaturize

The present invention is to solve the above problems, the battery cell of the contactless battery is not provided with a separate control circuit for preventing overcharge, it is possible to adjust the charging power in real time by checking the state of charge of the battery cell The purpose is to provide a contact charger.

In order to achieve the above object, a contactless charger according to an aspect of the present invention includes a magnetic field generating unit for receiving an AC current to form a magnetic field in the external space; A high frequency power driver for applying a high frequency AC current to the magnetic field generating unit; A current detector detecting a current value applied to the magnetic field generator; And a charging power controller which receives the detection result from the current detector and controls the high frequency power driver to control the power of the high frequency AC current applied to the magnetic field generator.

The magnetic field generating unit may be a coil to which high frequency alternating current is applied to both ends, and the charging power control unit may be a microprocessor controlling the driving of the high frequency power driving unit by monitoring a change in the current value received from the current detecting unit.

And a power supply unit for converting a commercial AC current into a direct current and supplying the same to the high frequency power driver, wherein the high frequency power driver includes a pulse signal generator for receiving a pulse driving signal from the microprocessor and outputting a pulse signal. ; And a power driver for receiving the pulse signal to generate a high frequency AC current in the form of a pulse by switching a DC current input from the power supply at a high speed.

The microprocessor adjusts the charging power by modulating the width of the pulse current, the frequency of the pulse current, the amplitude of the pulse or the number of pulses.

The power supply unit may include: an overvoltage cutoff filter unit configured to receive a commercial AC current and cut off an overvoltage current; A rectifying unit rectifying the AC current passing through the filter unit and converting the AC current into a DC current; And a constant voltage supply unit configured to output the converted DC current to the power driving unit at a constant voltage.

Preferably, the high frequency power driving unit intermittently applies a high frequency AC current to the magnetic field generating unit.

Battery charging set according to another aspect of the present invention includes a contactless charging battery and a contactless charger, the battery is a high-frequency alternating current in which the high-frequency alternating current is intermittently induced by a magnetic field generated intermittently in an external contactless charger Induction part; A rectifier for receiving the induced high frequency AC current and converting the current into a DC current; And a constant voltage / constant current supply unit configured to receive a DC current from the rectifier and supply charging power to a battery cell in a constant voltage-constant current mode, wherein the charger includes a magnetic field generator configured to receive an alternating current to form a magnetic field in an external space; A high frequency power driver for applying a high frequency AC current to the magnetic field generating unit; A current detector detecting a current value applied to the magnetic field generator; And a charging power control unit which receives the detection result from the current detection unit and controls the high frequency power driver to control the power of the high frequency AC current applied to the magnetic field generating unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

2 is a block diagram schematically showing the configuration of a contactless charger (C) and a battery (B) according to a preferred embodiment of the present invention.

Referring to FIG. 2, the contactless charger C according to the embodiment of the present invention may include a primary coil 200, a high frequency power driver 210, a current detector 220, a microprocessor 230, and a power supply unit ( 240).

The high frequency power driver 210 generates a magnetic field by applying a high frequency AC current of several tens of KHz to the primary coil 200 through a high speed switching operation. For example, the high frequency power driver 210 applies a high frequency AC current of 80 KHz to the primary coil 200. When the magnetic field is generated by the high frequency AC current in the primary coil 200, the charging power is transmitted to the battery B side in a contactless manner by the electromagnetic induction phenomenon.

Preferably, a known switching mode power supply (SMPS) may be employed as the high frequency power driver 210, but the present invention is not limited thereto.

The current detector 220 continuously measures the current value supplied from the high frequency power driver 210 to the primary coil 200 and provides the measured value to the microprocessor 230. For example, the current detector 220 may be configured in the form of a conventional current sensing circuit capable of detecting a current flowing in the primary coil.

The microprocessor 230 controls the overall operation of the charger C. In particular, the microprocessor 230 receives the current value from the current detector 220 and controls the high frequency power driver 210 to apply the high frequency AC current to the primary coil 200. To adjust the power.

Preferably, the microprocessor 230 controls the high frequency power driver 210 to modulate the width of the high frequency pulse (Pulse Width Modulation), the frequency of the pulse (Pulse Frequency Modulation), or modulate the number of pulses (Pulse) Number modulation or pulse amplitude modulation to adjust the power of the high frequency AC current. Then, the level of the charging power delivered to the battery B side is adjusted to prevent damage to the circuit inside the battery B.

The power supply unit 240 receives a commercial AC current 250 and converts it into a DC current, and supplies operating power to the high frequency power driver 210 and the microprocessor 230.

The contactless battery B according to an exemplary embodiment of the present invention includes a charging circuit module including a secondary coil 260, a rectifying unit 270, and a constant voltage / constant current supply unit 280, and charging by the charging circuit module is performed. It comprises a battery cell 300 made.

The secondary coil 260 generates a high frequency AC current by an electromagnetic induction phenomenon while a high frequency AC current is applied to the primary coil 200 provided in the charger C. At this time, the magnitude of the high frequency alternating current induced in the secondary coil 260 is proportional to the magnetic flux chained to the secondary coil 260.

The rectifier 270 smoothes the high frequency AC current induced by the secondary coil 260 and converts the DC current into a DC current.

The constant voltage / constant current supply unit 280 charges the battery cell 300 by applying the rectified DC current to the battery cell 290, but initially charges the battery cell 300 in the constant current mode while charging voltage is constant. The battery cell 300 is charged in the constant voltage mode to maintain a constant charging voltage instead of reducing the current.

3 is a diagram illustrating a change in the current value measured by the current detector 220 according to a preferred embodiment of the present invention, Figure 4 is a change in the charging current and charging voltage of the battery cell according to a preferred embodiment of the present invention It is a figure which illustrates.

3 and 4, when the battery B requiring charging is placed in the charging region of the contactless charger C, since the charging of the battery B proceeds, the load current of the high frequency power driver 210 increases. When the charging of the battery B is completed, the load current of the high frequency power driver 210 is reduced. Therefore, the microprocessor 230 checks the change in the current value received from the current detector 220 to determine the state in which the battery B is not placed in the charging region (hereinafter referred to as the charge standby state), and charging of the battery B is performed. Determine the ongoing state (hereinafter referred to as charging progress state) and the state of completion of charging of the battery B (hereinafter referred to as charge completion state), and in consideration of the charge standby state, the charge progress state, and the charge completion state The driving unit 210 is controlled to adjust the power value supplied to the primary coil 200.

In the charging progress state, since the battery cell 300 is charged in the constant voltage / constant current mode by the constant voltage / constant current supply unit 280, the value of the charging current required for charging the battery cell 300 is kept constant. Thereafter, when the voltage of the battery cell 300 exceeds the reference value (charging completed voltage) set in the constant voltage / constant current supply unit, the value of the charging current gradually decreases and the charging voltage value is kept constant. As the value of the charging current decreases, the contactless battery B consumes less power for charging the battery cell 300. As a result, the microprocessor 230 of the contactless charger C determines the state of charge of the battery cell 300 by detecting a change in current supplied to the primary coil 200, and drives the high frequency power driver 210. Can be controlled.

5 is a block diagram showing in more detail the configuration of a contactless charger (C) according to an embodiment of the present invention.

Referring to FIG. 5, the power supply unit 240 may include an overvoltage blocking filter unit 240a for blocking an overvoltage applied from a commercial AC power supply 250, and an AC current passing through the overvoltage blocking filter unit 240a as a DC current. It includes a rectifying unit 240b for converting, and a constant voltage supply unit 240c that receives the rectified DC current and supplies the rectified voltage to the microprocessor 230 and the high frequency power driver 210 at a constant voltage.

The high frequency power driving unit 210 receives a pulse driving signal from the microprocessor 230 and generates a pulse signal (Pulse Width Modulation 210a) and a pulse signal output from the pulse signal generating unit 210a. By switching the constant voltage DC current input from the constant voltage supply unit 240c at high speed to generate a high-frequency alternating current to the primary coil 200, and includes a power driver 210b.

Hereinafter, the contactless charging control method according to the present invention will be described in detail with reference to the above-described components.

First, in the non-charging mode, the high frequency power driver 210 of the charger C applies the high frequency AC current to the primary coil 200 for a short time at regular time intervals under the control of the microprocessor 230. For example, a high frequency AC current of 80 KHz is applied for 50 ms at 1 second intervals. Then, the primary coil 200 forms a magnetic field around each time a high frequency alternating current is applied.

The user places the battery B on the charger C for charging the battery B. After the battery B is positioned, when a high frequency alternating current is applied to the primary coil 200 of the charger C for a predetermined time, a magnetic field is generated in the primary coil 200, and as a result, The magnetic flux is chained to the secondary coil 270.

While the high frequency AC current is applied to the primary coil 200, the high frequency AC current is also induced in the secondary coil 260 of the battery B by the electromagnetic induction phenomenon. The duration of induction of the high frequency AC current is substantially the same as that of the application of the high frequency AC current to the primary coil 200.

The high frequency AC current induced in the secondary coil 260 is converted into a DC current by the rectifier 270 and then applied to the battery cell 300 via the constant voltage / constant current supply unit 280. Then, as the charging of the battery cell 300 is gradually performed, the voltage of both ends of the battery cell 300 rises until it is fully charged.

The constant voltage / constant current supply unit 290 charges the battery cell 300 by supplying a constant current in the constant current mode until the charging voltage of the battery cell 300 increases to a certain level, and then the voltage of the battery cell 300 is at a predetermined level. If more than this, the battery cell 300 is charged in the constant voltage mode. When charging the battery cell 300 in the constant voltage mode, the current supplied to the battery cell 300 gradually decreases.

As the current supplied by the constant voltage / constant current supply unit 290 decreases, the use current of the battery B side decreases. As a result, the amount of power transmitted from the primary coil 200 is reduced, and the microprocessor 230 determines that the battery cell 300 is fully charged based on the current value received from the current detector 220. The high frequency power driver 210 is controlled to lower the power of the high frequency AC current applied to the primary coil 200 by a predetermined level.

As described above, when the power of the high frequency AC current applied to the primary side coil 200 is reduced, the power of the high frequency AC current induced to the secondary side coil 260 is also reduced together with the electromagnetic induction phenomenon.

Through the feedback control of the above method, even if the contactless charging battery (B) does not have a separate overcharge prevention device, the current or voltage supplied by the constant voltage / constant current supply unit 280 can be maintained at an appropriate level, so that the battery cells It is possible to prevent the 300 from being overcharged.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

According to the present invention, the contactless charger checks the state of charge of the battery cell and adjusts the charging power in real time, thereby preventing overcharging of the battery cell of the contactless battery.

Since the battery cell of the contactless battery does not have to have a separate control circuit for preventing overcharging, it is possible to realize miniaturization of the contactless battery.

Claims (14)

In a contactless charger which delivers charging power by electromagnetic induction to the contactless charging battery side, A magnetic field generator that receives an AC current and forms a magnetic field in an external space; A high frequency power driver for applying a high frequency AC current to the magnetic field generating unit; A current detector detecting a current value applied to the magnetic field generator; And a charging power controller which receives the detection result from the current detector and controls the high frequency power driver to control the power of the high frequency alternating current applied to the magnetic field generating unit. The method of claim 1, The magnetic field generating unit is a contactless charger, characterized in that the coil to which a high frequency alternating current is applied to both ends. The method of claim 1, The charging power control unit is a contactless charger, characterized in that for monitoring the change in the current value received from the current detector to control the driving of the high frequency power driver. The method of claim 3, And a power supply unit which receives a commercial alternating current and converts it into a direct current and supplies the same to the high frequency power driving unit. The high frequency power drive unit, A pulse signal generator for receiving a pulse driving signal from the microprocessor and outputting a pulse signal; And And a power driver for receiving the pulse signal to generate a high frequency alternating current in the form of a pulse by switching a DC current input from the power supply at a high speed. The method of claim 4, wherein The microprocessor adjusts the charging power by modulating the width of the pulse current, the frequency of the pulse current, the amplitude of the pulse or the number of pulses. The method of claim 4, wherein the power supply unit, An overvoltage cutoff filter unit which receives a commercial AC current and cuts off the overvoltage current; A rectifying unit rectifying the AC current passing through the filter unit and converting the AC current into a DC current; And And a constant voltage supply unit configured to output the converted direct current to the power driving unit at a constant voltage. The method of claim 1, And the high frequency power driving unit intermittently applies a high frequency alternating current to a magnetic field generating unit. In a battery charge set comprising a contactless rechargeable battery and a contactless charger, The battery, A high frequency AC current induction unit in which a high frequency AC current is intermittently induced by a magnetic field generated by an external contactless charger intermittently; A rectifier for receiving the induced high frequency AC current and converting the current into a DC current; And a constant voltage / constant current supply unit receiving a DC current from the rectifier and supplying charging power to a battery cell in a constant voltage-constant current mode. The charger, A magnetic field generator that receives an AC current and forms a magnetic field in an external space; A high frequency power driver for applying a high frequency AC current to the magnetic field generating unit; A current detector detecting a current value applied to the magnetic field generator; And a charging power controller configured to receive the detection result from the current detector and to control the high frequency power driver to control the power of the high frequency AC current applied to the magnetic field generator. The method of claim 8, The magnetic field generating unit and the high frequency AC current inducing unit is a battery charging set, characterized in that the coil. The method of claim 8, The charging power control unit is a battery charge set, characterized in that for monitoring the change in the current value received from the current detector to control the driving of the high frequency power driver. The method of claim 10, And a power supply unit which receives a commercial alternating current and converts it into a direct current and supplies the same to the high frequency power driving unit. The high frequency power drive unit, A pulse signal generator for receiving a pulse driving signal from the microprocessor and outputting a pulse signal; And And a power driver for receiving the pulse signal to generate a high frequency alternating current in the form of a pulse by switching a DC current input from the power supply at a high speed. The method of claim 11, And the microprocessor adjusts the charging power by modulating the width of the pulse current, the frequency of the pulse current, the amplitude of the pulse or the number of pulses. The method of claim 11, wherein the power supply unit, An overvoltage cutoff filter unit which receives a commercial AC current and cuts off the overvoltage current; A rectifying unit rectifying the AC current passing through the filter unit and converting the AC current into a DC current; And And a constant voltage supply unit outputting the converted direct current to the power driving unit at a constant voltage. The method of claim 8, And the high frequency power driver intermittently applies a high frequency alternating current to a magnetic field generating unit.

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