KR20190063705A - Wireless Charging Method and Apparatus therefor - Google Patents

Abstract

The present invention relates to a wireless charging device for stable operation of a wireless charging device, and an operating method thereof. According to an embodiment of the present invention, the wireless charging device comprises: one or more transmission coils; a power conversion unit converting intensity of direct current (DC) power applied from the outside; an inverter converting the DC power into alternating current (AC) power; a resonance circuit including a resonance capacitor and the transmission coil and to which the AC power is applied; a first clock generation unit generating a reference clock signal; and a control unit. The control unit includes: a clock signal detection unit detecting a signal of the first clock generation unit; and a second clock generation unit generating the reference clock signal based on the detected signal of the clock signal detection unit.

Description

Technical Field [0001] The present invention relates to a wireless charging device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless power transmission technique, and more particularly to a wireless charging device and a method thereof.

2. Description of the Related Art [0002] Generally, as an example of an electrical connection between a charging device and a battery for charging electric power of a battery, a commercial electric power is supplied to a terminal for converting electric power into voltage and current corresponding to the battery, Supply method. This type of terminal supply is accompanied by the use of physical cables or wires. Therefore, when handling a lot of terminal-supplied equipment, many cables occupy considerable work space, are difficult to organize, and are not well apparent. Also, the terminal supply method may cause problems such as instantaneous discharge due to different potential difference between terminals, burnout due to foreign substances, fire, natural discharge, battery life and deterioration of performance.

In order to solve such a problem, a charging system (hereinafter referred to as a "wireless charging system") and a control method using a method of transmitting power wirelessly are proposed. In addition, since the wireless charging system has not been installed in some portable terminals in the past and the consumer has to purchase a separate wireless charging receiver accessory, the demand for the wireless charging system is low, but the wireless charging user is expected to increase rapidly. Wireless charging function is expected to be equipped basically.

Generally, a wireless charging system comprises a wireless power transmitter for supplying electric energy in a wireless power transmission mode and a wireless power receiver for receiving electric energy supplied from a wireless power transmitter to charge the battery.

Such a wireless charging system may transmit power by at least one wireless power transmission scheme (e.g., electromagnetic induction scheme, electromagnetic resonance scheme, RF wireless power transmission scheme, etc.).

Most of the wireless charging devices receive the reference clock signal for signal synchronization or frequency generation, and supply the system clock to the sub-channel board or configuration. At this time, if a reference clock signal is not generated or an error occurs, a reference signal for the operation of the wireless charging system is not supplied, thereby causing a problem such as an operation error of the wireless charging system or an interruption of charging. That is, when the operation of all the configurations and the error of the reference clock signal for charging occur in the wireless charging system, the system becomes fatal or the wireless charging operation is not executed.

The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a wireless charging device and a method thereof.

It is still another object of the present invention to provide a wireless charging device and method thereof for preventing a malfunction of a wireless charging device due to an external shock or an operation error.

It is still another object of the present invention to provide a wireless charging device and method for providing a stable clock signal and for stable operation of the wireless charging device accordingly.

The technical problems to be solved by this embodiment are not limited to the above-mentioned technical problems and other technical problems which are not mentioned are clarified from the following description to those skilled in the art to which the embodiments belong, .

The wireless charging apparatus according to the present embodiment includes at least one transmission coil; A power converter for converting an intensity of direct current power applied from the outside; An inverter for converting the DC power into AC power; A resonant circuit including a resonant capacitor and a transmission coil, to which the AC power is applied; A first clock generator for generating a reference clock signal; And a control unit, wherein the control unit comprises: a clock signal sensing unit for sensing a signal of the first clock generating unit; And a second clock generator for generating a reference clock signal based on the detection signal of the clock signal detector.

In addition, the controller may control the second clock generator to be driven when the reference clock signal is not received from the first clock generator at the initial power-on or during the wireless charging operation.

In addition, the controller may control the second clock generator to operate when the reference clock signal is not received more than a threshold number of times.

Also, the second clock generator may include a transistor or a FET.

The frequency synthesizer may further include a frequency sensing unit for sensing an operation frequency generated by the reference clock signal when the reference frequency is generated through the second clock generator.

Also, the frequency sensing unit may check the sensed operating frequency and output the reference clock signal correction request signal when the operating frequency is in error.

In addition, the error of the operating frequency can be detected when the operating frequency generated by the reference clock signal is not included in the threshold range.

A wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver according to an embodiment of the present invention includes the steps of: checking whether a reference clock signal is received from a first clock generator during a wireless power transmitter operation; Requesting operation of the second clock generator when the reference clock signal is not received through the first clock generator; Generating a reference clock signal through the second clock generator; And starting operation of the wireless charging device based on the generated reference clock signal.

Also, the confirmation of whether the reference clock signal is received through the first clock generator may be performed during initial power-on or wireless charging operation of the wireless power transmitter.

Detecting an operation frequency according to the reference clock signal when the reference clock signal is generated through the second clock generator; Requesting correction of the reference clock signal if the operating frequency is not within a threshold frequency range; And correcting the reference clock signal output from the second clock generator based on the correction request signal.

Effects of the wireless charging device having the wireless communication coil according to the present embodiment will be described as follows.

The present embodiment provides a wireless charging apparatus and a method thereof.

The present embodiment can also have an effect of preventing a malfunction of the wireless charging device from occurring due to an error in the clock signal generation by monitoring the clock signal of the wireless charging device and detecting the error according to the clock signal.

In addition, the present embodiment solves the problem caused by a non-occurrence of a reference signal due to various external factors, thereby achieving stable wireless charging.

The effects obtainable in the present embodiment are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description There will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. It is to be understood, however, that the technical features of the present invention are not limited to the specific drawings, and the features disclosed in the drawings may be combined with each other to constitute a new embodiment.
1 is a block diagram for explaining a wireless charging system according to an embodiment.
2 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.
3 is a flow diagram of a wireless power transmitter according to one embodiment.
4 is a flowchart illustrating an operation of a wireless power transmitter according to another embodiment of the present invention.
5 is a flowchart of a wireless power transmitter according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which the embodiments are applied will be described in detail with reference to the drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

The present invention is not necessarily limited to these embodiments, as long as all of the constituent elements of the embodiment are described as being combined or operated together. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program may be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing embodiments. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

In the description of the embodiment, in the case of being described as being formed on the "upper or lower", "before" or "after" of each component, (Lower) "and" front or rear "encompass both that the two components are in direct contact with each other or that one or more other components are disposed between the two components.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

In the description of the embodiments, an apparatus for transmitting wireless power on a wireless power charging system includes a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a transmitter, a transmitter, a transmitter, , A wireless power transmission device, a wireless power transmitter, a wireless charging device, and the like. For the sake of convenience, a wireless power receiving device, a wireless power receiving device, a wireless power receiving device, a wireless power receiving device, a receiving terminal, a receiving side, a receiving device, a receiver Terminals and the like can be used in combination.

The wireless charging device according to the embodiment may be configured as a pad type, a cradle type, an access point (AP) type, a small base type, a stand type, a ceiling embedded type, a wall type, Power may be transmitted to the device.

As an example, a wireless power transmitter can be used not only on a desk or on a table, but also developed for automobiles and used in a vehicle. A wireless power transmitter installed in a vehicle can be provided in a form of a stand that can be easily and stably fixed and mounted.

A mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation device, an MP3 player, (Hereinafter referred to as a " device ") capable of charging a battery by mounting a wireless power receiving means according to an embodiment, but not limited thereto, may be used for a small electronic device such as a toothbrush, an electronic tag, a lighting device, Quot;), and the term terminal or device may be used in combination. A wireless power receiver according to another embodiment may also be mounted on a vehicle, an unmanned aerial vehicle, an air drone or the like.

Generally, a wireless power transmitter and a wireless power receiver that constitute a wireless power system can exchange control signals or information through in-band communication or Bluetooth low energy (BLE) communication. Here, the in-band communication and the BLE communication can be performed by a pulse width modulation method, a frequency modulation method, a phase modulation method, an amplitude modulation method, an amplitude and phase modulation method, and the like. For example, the wireless power receiver can transmit various control signals and information to the wireless power transmitter by generating a feedback signal by switching on / off the current induced through the reception coil in a predetermined pattern. The information transmitted by the wireless power receiver may include various status information including received power intensity information. At this time, the wireless power transmitter can calculate the charging efficiency or the power transmission efficiency based on the received power intensity information.

1 is a block diagram illustrating a wireless charging system according to an embodiment

Referring to FIG. 1, the wireless charging system includes a wireless power transmission terminal 10 for wirelessly transmitting power, a wireless power receiving terminal 20 for receiving the transmitted power, and an electronic device 30 Lt; / RTI >

For example, the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 can perform in-band communication in which information is exchanged using the same frequency band as that used for wireless power transmission. In another example, the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 perform out-of-band communication in which information is exchanged using a different frequency band different from the operating frequency used for wireless power transmission .

For example, information exchanged between the wireless power transmitting terminal 10 and the wireless power receiving terminal 20 may include control information as well as status information of each other. Here, the status information and the control information exchanged between the transmitting and receiving end will become more apparent through the description of the embodiments to be described later.

The in-band communication and the out-of-band communication may provide bidirectional communication, but the present invention is not limited thereto. In another embodiment, the in-band communication and the out-of-band communication may be provided.

For example, the unidirectional communication may be that the wireless power receiving terminal 20 transmits information only to the wireless power transmitting terminal 10, but the present invention is not limited thereto, and the wireless power transmitting terminal 10 may transmit information Lt; / RTI >

In the half duplex communication mode, bidirectional communication is possible between the wireless power receiving terminal 20 and the wireless power transmitting terminal 10, but information can be transmitted only by any one device at any time.

The wireless power receiving terminal 20 according to the embodiment may acquire various status information of the electronic device 30. [ For example, the status information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, And is information obtainable from the electronic device 30 and available for wireless power control.

2 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.

2, the wireless power transmitter 200 includes a DC-DC converter 210, an inverter 220, a resonant circuit 230, a communication unit 340, a sensing unit 250, A power supply unit 260, and a first clock generating unit 270. An alarm unit 280 and a control unit 290. [

The power supply unit 260 may receive DC power from an external power supply terminal or a battery and transmit the DC power to the DC-DC converter 210. Here, the battery may be configured to be installed inside the wireless power transmitter 200 so as to be chargeable, but this is merely an example, and the power source 260 of the wireless power transmitter 300 in the form of a secondary battery or an external battery ) May be connected via a predetermined cable.

The DC-DC converter 210 may convert the intensity of the DC power input from the power supply unit 260 into DC power of a specific intensity under the control of the controller 290. For example, the DC-DC converter 210 may include, but is not limited to, a variable voltage generator capable of adjusting the voltage.

The inverter 220 can convert the converted DC power into AC power.

The inverter 220 converts the DC power signal input through the plurality of switch controls into an AC power signal and outputs the AC power signal.

For example, the inverter 220 may include a full bridge circuit, but the present invention is not limited thereto and may include a half bridge.

In another example, the inverter 220 may be configured to include both a half bridge circuit and a full bridge circuit. In this case, the control unit 290 dynamically determines whether the inverter 220 is operated as a half bridge or a bridge .

 The wireless power transmitter according to one embodiment may adaptively control the bridge mode of the inverter 220 depending on the strength of the power required by the wireless power receiver.

Here, the bridge mode includes a half bridge mode and a full bridge mode. For example, if the wireless power receiver requires a low power of 5 W, the controller 290 may control the inverter 220 to operate in the half bridge mode.

On the other hand, if the wireless power receiver requires 15 W of power, the controller 290 can control to operate in the full bridge mode. In another example, the wireless power transmitter may adaptively determine the bridge mode according to the sensed temperature and drive the inverter 220 according to the determined bridge mode.

For example, when the temperature of the wireless power transmission apparatus exceeds the predetermined reference value while the wireless power is being transmitted through the half bridge mode, the controller 290 may disable the half bridge mode and control the full bridge mode to be activated. That is, in the wireless power transmission apparatus, the voltage is raised through the full bridge circuit for the power transmission of the same intensity, and the intensity of the current flowing in the resonance circuit 230 is reduced so that the internal temperature of the wireless power transmission apparatus is lower than a predetermined reference value As shown in Fig.

Generally, the amount of heat generated in an electronic component mounted on an electronic device may be more sensitive to the intensity of a current than the voltage applied to the electronic component.

In addition, the inverter 230 can change the intensity of the AC power as well as convert the DC power to the AC power.

For example, the inverter 220 may adjust the frequency of the alternating current power output by controlling the frequency of the reference alternating current signal used for generating the alternating-current power under the control of the controller 290. For this purpose, the inverter 220 may include a frequency oscillator that generates a reference AC signal having a specific frequency, but this is only one embodiment, and another embodiment may be configured such that the frequency oscillator is separate from the inverter 220 And may be mounted on one side of the wireless power transmitter 200.

In another example, the wireless power transmitter 200 may further include a gate driver (not shown) for controlling a switch provided in the inverter 220. In this case, the gate trigger can receive at least one pulse width modulated signal from the control unit 290 and control the switch of the inverter 220 according to the received pulse width modulated signal. The controller 290 can control the intensity of the output power of the inverter 220 by controlling the duty cycle of the pulse width modulation signal, that is, the duty ratio and the phase. The control unit 290 may adaptively control the duty cycle and phase of the pulse width modulation signal based on the feedback signal received from the wireless power receiving apparatus.

The sensing unit 250 may measure the voltage / current of the DC-converted power and provide the measured voltage / current to the controller 290. Also, the sensing unit 250 may measure the internal temperature of the wireless power transmitter 200 or the inside of the charging interface (surface) to determine whether overheating occurs, and provide the measurement result to the controller 290. For example, the control unit 290 may adaptively cut off the power supply from the power supply unit 260 based on the voltage / current value or the internal temperature value measured by the sensing unit 250. To this end, a power cut-off circuit for shutting off power supplied from the power supply unit 260 may be further provided at one side of the DC-to-AC converter 210.

The sensing unit 250 may feedback the operating frequency output from the resonant circuit 330 to detect the operating frequency. The sensing unit 250 may determine the operating frequency generated by the reference output signal output from the clock generator according to the present embodiment and determine whether the operating frequency is within the critical range. Also, the sensing unit 250 confirms the operation frequency and if it is not within the critical range, it confirms that the reference clock signal generated by the clock generator is in error, and outputs the correction request signal of the reference clock signal to the controller 290 .

The modulator 242 may modulate the control signal generated by the controller 290 and transmit the modulated control signal to the resonance coil 330. Here, the modulation scheme for modulating the control signal includes a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a phase shift keying (PSK) modulation scheme, a pulse width modulation scheme, A differential bi-phase modulation method, and the like.

The demodulator 241 can demodulate a signal received through the transmission coil and transmit the demodulated signal to the controller 290. The demodulated signal may include a signal strength indicator, an error correction (EC) indicator for power control during wireless power transmission, an end of charge indicator (EOC), an overvoltage / overcurrent / overheat indicator, And various status information for identifying the status of the wireless power receiver may be included. As another example, the demodulated signal may include FOD status information including a value of at least one of a reference quality factor value and a reference frequency value.

The first clock generator 270 may generate a reference clock signal for operation and power transmission of the wireless charging device. For example, the first clock generator 270 may generate a reference clock signal for identifying a time point at which to transmit a sensing signal for sensing the wireless power receiver through the resonant circuit 230. The first clock generator 270 may generate a reference clock signal for counting the time for transmitting power to the sensed wireless power receiver through the resonant circuit 230. [ The first clock generator 270 may generate a reference clock signal for generating an operating frequency for transmitting power to the wireless power transmitter through the resonant circuit 230. The first clock generator 270 may be an oscillator including a crystal (X-tal) or a resonator.

The control unit 290 may perform operation time and end time of the wireless charging apparatus or operation frequency generation for power transmission based on the reference clock signal generated and output by the first clock generation unit 270. [ The control unit 290 can detect whether the reference clock signal is inputted through the first clock generating unit 270 when the initial charging of the wireless charging apparatus is performed or during the wireless charging mode. For this purpose, the clock signal detection unit 291 may be included, but the present invention is not limited thereto, and a separate detection unit 291 may not be included. The controller 290 controls the second clock generator 292 included in the controller 290 to generate and output the reference clock signal when the reference clock signal is not detected through the first clock generator 270 Can be controlled. Specifically, when the reference clock signal is not applied from the first clock generating unit 270 through the clock signal detecting unit 291, the controller 290 controls the first clock generating unit 270 such that the first clock generating unit 270 is physically damaged, It is possible to judge an error by various factors. Accordingly, the controller 290 may generate and output a reference clock signal for operation of the wireless charging device using the second clock generator 292 included in the controller 290. At this time, the operation of the second clock generator 292 included in the controller 290 may generate and output a clock signal similar to the generation and output of the reference clock signal output from the first clock generator 270. The second clock generator 292 may include a transistor or a field effect transistor (FET). That is, the second clock generator 292 can generate and output the reference clock signal in accordance with the cycle of the on / off operation.

The storage unit (not shown) may store information of the clock generating unit to be activated or deactivated among the first clock generating unit 270 or the second clock generating unit 292. The storage unit may store information of a reference clock signal to be generated and output by the first clock generating unit 270 and the second clock generating unit 292.

The operation of the wireless charging apparatus using the wireless charging apparatus having the configuration as shown in FIG. 2 will be described in detail with reference to FIGS. 3 to 5. FIG.

3, the wireless charging device may include a step of inputting initial power (S302). Specifically, the wireless charging device may sense a power input for driving the wireless charging device through the power supply 260 have.

The wireless recharging apparatus can monitor whether the reference clock signal is applied through the first clock generator 270 when the initial power is applied. (S304) The wireless recharging apparatus is configured such that the first clock generator 270 receives the initial power It is possible to generate a reference clock signal and confirm whether the reference clock signal is applied to the controller 290. [ For example, the controller 290 may monitor whether a 5 MHz sine wave, which is a reference clock signal, is input through the first clock generator 270. The reference clock signal is merely an example, and the value may vary depending on the specification and the setting state of the wireless charging system.

The wireless charging device monitors the input of the clock signal and determines whether the reference clock signal is output from the first clock generator 270 according to the monitoring result (S306). That is, the controller 260 of the wireless charging device Determines whether a 5 MHz sinusoidal reference clock signal is received through the first clock generating unit 270. [

The wireless recharging apparatus can determine the number N of times of sensing failure (N times) when the reference clock signal is not detected (S308). In other words, in the wireless recharging apparatus, the number of times the reference clock signal is undetected (N times) Or more.

The wireless charging device outputs a driving request signal of the second clock generator 292 in the controller 290 when it is determined that the number of times the reference clock signal is not detected is greater than or equal to the reference number of times (N times) (S310) The controller 290 may determine that the reference clock signal is not received from the first clock generator 270 through the clock signal detector 291 as an operation error of the first clock generator 270 . Accordingly, the second clock generator 292 in the controller 290 may be requested to generate the reference clock signal.

When the second clock generator 292 is driven (S312), the second clock generator 292 may output the reference clock signal to be output from the first clock generator 270 (S314). At this time, The clock generating unit 292 is constituted by a switching element such as a transistor or a FET and can output a reference clock signal according to the operation period of the switching element. That is, the second clock generator 292 can output the reference clock signal of 5 MHz output from the first clock generator 270 according to the malfunction of the first clock generator 270.

The wireless charging device can execute the wireless charging mode based on the reference clock signal output through the second clock generator 292. [

As described above, in this embodiment, the reference clock signal can be input through the first clock generator 270, which is independently configured when the initial power supply of the wireless charging device is input. However, when the first clock generator 270 is driven And if it is not normal, the second clock generator outputs the reference clock signal so that the wireless charging operation can be normally executed.

4, the operation of the wireless charging device according to the error detection of the first clock generator during the wireless charging mode of the wireless charging device will be described in detail.

4 is a flowchart illustrating an operation of a wireless power transmitter according to another embodiment of the present invention.

Referring to FIG. 4, the wireless charging device may execute a wireless charging mode in which power is transmitted to a wireless power receiver. (S402) In this embodiment, a wireless charging device starts a power transmission step of transmitting power to a wireless power receiver However, the present invention is not limited to this, and may include all cases in which an initial power is input and an error occurs during normal operation of the wireless charging device.

The wireless charging device may detect an abnormal wireless charging mode termination during the wireless charging mode (S404). For example, when the wireless charging device is performing power transmission to the wireless power receiver, abnormal wireless charging mode termination - for example, A state in which the normal wireless charging mode such as the suspension of the wireless charging mode due to the buffering or the wireless charging stop due to the removal of the wireless power receiver is not terminated, or the like, occurs, the wireless charging apparatus can perform the initialization operation.

The wireless charging device can monitor the input of the clock signal after the initialization operation. (S408) The wireless charging device determines whether the first clock generator 270 generates the reference clock signal after initialization and is applied to the controller 290 Can be confirmed. For example, the controller 290 may monitor whether a 5 MHz sine wave, which is a reference clock signal, is input through the first clock generator 270. The reference clock signal is merely an example, and the value may vary depending on the specification and the setting state of the wireless charging system.

The wireless charging device monitors a clock signal input and determines whether a reference clock signal is output from the first clock generator 270 according to the monitoring result (S410). That is, the controller 290 of the wireless charging device The first clock generator 270 determines whether a 5 MHz sinusoidal reference clock signal is received.

The wireless recharging apparatus can determine the number of times the reference clock signal is not sensed (N times). That is, the wireless charging device can determine whether the number of times the reference clock signal is undetected (N times) is equal to or greater than the reference number.

The wireless charging device can output the driving request signal of the second clock generator 292 in the controller 290 when it is determined that the number of times the reference clock signal is undetected exceeds the reference number of times (N times) (S414) The controller 290 determines that the reference clock signal is not received from the first clock generator 270 through the clock signal detector 291 and determines that the reference clock signal is an operation error of the first clock generator 270 have. Accordingly, the second clock generator 292 in the controller 290 may be requested to generate the reference clock signal.

When the second clock generator 292 is driven (S416), the second clock generator 292 may output the reference clock signal to be output from the first clock generator 270 (S418). At this time, The unit 292 is constituted by a switching element such as a track gauge or a FET, and can output a reference clock signal in accordance with the operation period of the switching element. That is, the second clock generator 292 can output the reference clock signal of 5 MHz outputted from the first clock generator 270 according to the malfunction of the first clock generator 270.

The wireless charging device can execute the wireless charging mode based on the reference clock signal output through the second clock generator 292. [

As described above, in this embodiment, the wireless charging device can be operated in the wireless charging mode by receiving the reference clock signal through the first clock generator 270, which is independently configured. At this time, when the abnormal charging mode is ended The second clock generator may generate and output the reference clock signal by confirming whether or not the clock signal is inputted. That is, even when the wireless charging mode is being executed, it is possible to prevent the wireless charging operation from stopping or malfunctioning due to the error of the clock generating unit.

5, the operation of the wireless charging device for enhancing the reliability of the wireless charging operation in the wireless charging mode according to the operation of the second clock generator in accordance with the malfunction of the first clock generator in one embodiment and another embodiment will be described in detail Explain.

5 is a flowchart illustrating an operation of a wireless security device according to another embodiment of the present invention.

Referring to FIG. 5, in still another embodiment, the present invention relates to a wireless charging operation in a state where a reference clock signal is generated in a second clock generating unit according to the embodiment described in FIGS. 3 and 4. FIG. When the reference clock signal is generated in the second clock generating unit, the reliability of the signal is not higher than that of the first clock generating unit, thereby reducing the occurrence of an error in the operating frequency according to the reference clock signal.

Specifically, when the wireless charging mode is executed by the second clock generator 292 (S502), the second clock generator 292 generates the same clock signal as the reference clock signal output from the first clock generator 270 Thereby generating and outputting the reference clock signal. (S504)

The wireless charging apparatus can generate the charging frequency based on the reference clock signal output from the second clock generating unit 292. (S506) Specifically, the reference clock signal output from the second clock generating unit 292 Lt; RTI ID = 0.0 > frequency. ≪ / RTI > For example, when the reference clock signal of 5 MHz is output through the second clock generator 292, the controller 290 may generate the charging frequency to be provided to the resonance coil 230 based on the reference clock signal. The reference clock signal and the charging frequency are examples, and the range may vary depending on the characteristics of the wireless charging device.

Thereafter, the wireless charging device can generate the operating frequency at a resonant frequency corresponding to the wireless power receiver to perform power transmission (S508)

At this time, the wireless charging device can check the charging frequency provided to the resonance circuit 330 by feeding back the frequency to the resonance circuit 330 through the frequency sensing part 251 of the sensing part 250. (S510) Specifically, The charging frequency provided to the resonance circuit 330 may be fed back to determine whether the generated charging frequency is generated at the charging frequency required by the wireless charging device.

The wireless charging device may determine whether the feedback charging frequency is within a frequency threshold range (S512). In other words, the wireless charging device may determine whether the feedback charging frequency is within a critical range including a charging frequency required by the wireless charging device As shown in Fig.

If the charging frequency is not within the predetermined threshold frequency range, the wireless charging device determines the error of the reference clock signal output from the second clock generator 292.

The frequency sensing unit 251 may output a correction request signal corresponding to the error of the reference clock signal to the control unit 290. In operation S514, And may request the controller 290 to correct the output of the reference clock signal of the second clock generator 292.

Accordingly, the second clock generator 292 can correct the output reference clock signal according to the detection result of the frequency detector 251 and execute the wireless charging mode based on the corrected reference clock signal (S516)

When the reference clock signal is generated through the second clock generator in accordance with a malfunction of the first clock generator, the wireless recharging apparatus outputs the frequencies generated based on the reference clock signal to the high- And to correct the reference clock signal based on the fed-back frequency.

It will be apparent to those skilled in the art that the embodiments may be embodied in other specific forms without departing from the spirit and essential characteristics of the embodiments.

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (10)

At least one transmitting coil;
A power converter for converting an intensity of direct current power applied from the outside;
An inverter for converting the DC power into AC power;
A resonant circuit including a resonant capacitor and a transmission coil, to which the AC power is applied;
A first clock generator for generating a reference clock signal;
And a control unit,
Wherein the control unit includes: a clock signal sensing unit for sensing a signal of the first clock generating unit;
And a second clock generator for generating a reference clock signal based on the sensing signal of the clock signal sensing unit. The method according to claim 1,
The control unit
And controls the second clock generator to drive the first clock generator when the reference clock signal is not received from the first clock generator when the initial power is applied or during the wireless charging operation. 3. The method of claim 2,
The control unit
And controls to drive the second clock generator when the reference clock signal is not received more than a threshold number of times.
The method according to claim 1,
Wherein the second clock generator comprises a transistor or a FET. The method according to claim 1,
And a frequency sensing unit for sensing an operating frequency generated by the reference clock signal when generating the reference frequency through the second clock generating unit. 6. The method of claim 5,
The frequency sensing unit
And outputs the reference clock signal correction request signal when the operating frequency is in error. The method according to claim 6,
The error in the operating frequency
Wherein the operating frequency generated by the reference clock signal is not included in the threshold range. A wireless charging method in a wireless power transmitter for wirelessly transmitting power to a wireless power receiver,
Checking whether a reference clock signal is received from a first clock generating unit during a wireless power transmitter operation;
Requesting operation of the second clock generator when the reference clock signal is not received through the first clock generator;
Generating a reference clock signal through the second clock generator;
And initiating operation of the wireless charging device based on the generated reference clock signal. 9. The method of claim 8,
Wherein the confirmation of whether the reference clock signal is received through the first clock generator is performed when the power of the wireless power transmitter is initialized or during a wireless charging operation. 9. The method of claim 8,
Sensing an operation frequency according to the reference clock signal when the reference clock signal is generated through the second clock generator;
Requesting correction of the reference clock signal if the operating frequency is not within a threshold frequency range;
And correcting a reference clock signal output from the second clock generator based on the correction request signal.

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