KR20180085175A - Voltage limit circuit for wireless charging and wireless power transmitter therewith - Google Patents

Abstract

The present invention relates to a voltage limit circuit for wireless charging and a wireless power transmitter equipped with the same. A voltage limit circuit assembly, which is provided in a wireless power transmitter according to one embodiment of the present invention to control power supplied to an inverter, includes: a first cut-off circuit for comparing an input voltage with a predetermined reference voltage to cut off power supplied to the inverter when a low voltage is detected; and a second cut-off circuit which cuts off power supplied to the inverter when the voltage supplied from the first cut-off circuit exceeds a predetermined threshold voltage. Therefore, the present invention can prevent devices of a wireless charging apparatus from being damaged, in advance, by blocking the low voltage as well as an overvoltage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a voltage cut-off circuit for wireless charging and a wireless power transmitter equipped with the voltage cut-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless charging technology, and more particularly, to a voltage blocking circuit capable of blocking an undervoltage as well as an overvoltage by using an analog circuit element and a wireless power transmitting apparatus equipped with the same.

The wireless power transmission technology (wireless power transmission or wireless energy transfer) is a technology to transmit electric energy from the transmitter to the receiver wirelessly using the induction principle of the magnetic field. In the 1800s, electric motor or transformer And thereafter, a method of radiating electromagnetic waves such as radio waves, lasers, high frequencies, and microwaves to transfer electrical energy has also been attempted. Our electric toothbrushes and some wireless shavers are actually charged with electromagnetic induction.

Up to the present, energy transmission using radio may be roughly classified into a magnetic induction method, an electromagnetic resonance method, and an RF transmission method using a short wavelength radio frequency.

In the magnetic induction method, when two coils are adjacent to each other and a current is supplied to one coil, a magnetic flux generated at this time causes an electromotive force to the other coils. As a technology, . The magnetic induction method has the disadvantage that it can transmit power of up to several hundred kilowatts (kW) and the efficiency is high, but the maximum transmission distance is 1 centimeter (cm) or less, so it is usually adjacent to the charger or the floor.

The self-resonance method is characterized by using an electric field or a magnetic field instead of using electromagnetic waves or currents. The self-resonance method is advantageous in that it is safe to other electronic devices or human body since it is hardly influenced by the electromagnetic wave problem. On the other hand, it can be used only at a limited distance and space, and has a disadvantage that energy transfer efficiency is somewhat low.

Short wavelength wireless power transmission - simply, RF transmission - takes advantage of the fact that energy can be transmitted and received directly in radio wave form. This technology is a RF power transmission system using a rectenna. Rectena is a combination of an antenna and a rectifier, which means a device that converts RF power directly into direct current power. That is, the RF method is a technique of converting an AC radio wave into DC and using it. Recently, as the efficiency has improved, commercialization has been actively researched.

Wireless power transmission technology can be applied not only to mobile but also to various industries such as car, IT, railway, and household appliance industries.

A conventional wireless power receiver has transmitted to the wireless power transmitter a predetermined control signal indicating that an overvoltage has been detected if the rectifier output voltage exceeds a predetermined overvoltage reference value. In this case, the wireless power receiver is provided with a separate overvoltage breaker to prevent overvoltage from being delivered to the load or electronic device during overvoltage sensing.

In particular, although the conventional wireless charging system is equipped with an overvoltage shutoff function, there is a separate circuit for low voltage shutdown, which prevents the transmitter from being damaged due to the occurrence of an overcurrent.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a voltage cutoff circuit for wireless charging and a wireless power transmission device equipped with the same.

It is another object of the present invention to provide a voltage blocking circuit assembly capable of blocking a low voltage as well as a high voltage and a wireless power transmission apparatus equipped with the same.

It is yet another object of the present invention to provide a wireless power transmission apparatus capable of adaptively driving a voltage cutoff circuit based on information collected from a wireless power receiver.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

The present invention can provide a power cut-off circuit assembly for wireless charging and a wireless power transmission apparatus using the same.

A voltage blocking circuit assembly included in a wireless power transmission apparatus according to an exemplary embodiment of the present invention controls power supply to an inverter. The voltage blocking circuit assembly compares an input voltage with a predetermined reference voltage. When a low voltage is detected, And a second blocking circuit for blocking the power supply to the inverter when the voltage supplied from the first blocking circuit exceeds a predetermined threshold voltage.

The first blocking circuit includes a voltage divider circuit for dividing a voltage applied from a power source or a DC-DC converter to provide the input voltage, a reference voltage supply circuit for supplying the reference voltage, And a first blocking switch for controlling power supply to the second blocking circuit according to the output of the comparison circuit.

Also, if the input voltage is less than the reference voltage, power supply to the second blocking circuit is interrupted, and power may be supplied to the second blocking circuit if the input voltage is greater than the reference voltage.

The first blocking switch may include a first transistor connected to an output terminal of the comparing circuit and a second transistor connected to a drain of the first transistor. When the input voltage is smaller than the reference voltage, The transistors and the switches of the second transistor are both turned OFF, so that power supply to the second blocking circuit can be interrupted.

The second blocking circuit may include a high voltage sensing circuit for sensing whether a voltage supplied from the first blocking circuit is higher than a predetermined threshold voltage, a second blocking switch for controlling power supply to the inverter, And a switch control circuit for controlling the second cut-off switch to cut off power supplied to the inverter if the voltage exceeds a threshold voltage.

Here, the high voltage sensing circuit may be a zener diode that supplies a reverse current to the switch control circuit at the threshold voltage.

The switch control circuit may include a third transistor operated by the reverse current, and a resistor disposed between the third transistor and the zener diode for preventing the third transistor from being damaged by the reverse current .

The second blocking switch may include a fourth transistor and a fifth transistor that are turned off when the third transistor is switched on to block transmission of power supplied from the first blocking circuit to the inverter .

According to another aspect of the present invention, there is provided a wireless power transmission apparatus including: a voltage blocking circuit assembly for sensing a DC voltage supplied from a power source or a DC-DC converter to cut off a preset low voltage and a high voltage; An inverter for receiving the AC power signal and converting it into an AC power signal, and a resonance circuit for wirelessly transmitting the AC power signal.

The wireless power transmission apparatus may further include a blocking circuit control switch for switching the power supplied from the power source or the DC-DC converter to either the voltage blocking circuit assembly or the inverter according to a control signal of the controller and the controller can do.

Also, the controller may be configured to determine, based on at least one of information on the power reception class collected from the wireless power receiver, information on the strength of the requested power, information on the strength of the received power, The blocking circuit control switch can be controlled.

The voltage blocking circuit assembly may include a first blocking circuit that compares an input voltage with a predetermined reference voltage to cut off power supply to the inverter when the low voltage is sensed, And, if exceeded, a second disconnecting circuit for interrupting power supply to the inverter.

The first blocking circuit includes a voltage divider circuit for dividing a DC voltage applied from the power source or the DC-DC converter to provide the input voltage, a reference voltage supply circuit for supplying the reference voltage, And a first blocking switch for controlling power supply to the second blocking circuit according to the output of the comparison circuit.

Also, if the input voltage is less than the reference voltage, power supply to the second blocking circuit is interrupted, and power may be supplied to the second blocking circuit if the input voltage is greater than the reference voltage.

Also, Wherein the first blocking switch includes a first transistor connected to an output terminal of the comparison circuit and a second transistor connected to a drain of the first transistor, and when the input voltage is smaller than the reference voltage, The switches of the second transistors are all turned off, and the power supply to the second blocking circuit can be interrupted.

The second blocking circuit may include a high voltage sensing circuit for sensing whether a voltage supplied from the first blocking circuit is higher than a predetermined threshold voltage, a second blocking switch for controlling power supply to the inverter, And a switch control circuit for controlling the second cut-off switch to cut off power supplied to the inverter if the voltage exceeds a threshold voltage.

The high voltage sensing circuit may be a zener diode that supplies a reverse current to the switch control circuit at the threshold voltage.

The switch control circuit may include a third transistor operated by the reverse current, and a resistor disposed between the third transistor and the zener diode for preventing the third transistor from being damaged by the reverse current .

The second blocking switch may include a fourth transistor and a fifth transistor that are turned off when the third transistor is switched on to block transmission of power supplied from the first blocking circuit to the inverter .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And can be understood and understood.

Effects of the circuit assembly and the apparatus according to the present invention will be described as follows.

The present invention has the advantage of providing a voltage cut-off circuit for wireless charging and a wireless power transmission device equipped with the same.

The present invention also has the advantage of providing a voltage blocking circuit assembly capable of blocking not only high voltage but also low voltage, and a wireless power transmission device equipped with the same.

The present invention also has the advantage of providing a wireless power transmission device capable of adaptively driving a voltage cutoff circuit based on information collected from a wireless power receiver.

It is also an advantage of the present invention to provide a voltage blocking circuit assembly capable of blocking the overvoltage from being supplied to the wireless power receiver and a wireless power transmission device equipped with the same.

In addition, the present invention has an advantage of providing a voltage blocking circuit assembly and a wireless power transmission device equipped with the voltage blocking circuit assembly, which can prevent the transmitter from being damaged through low voltage cutoff.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description 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 illustrating a wireless charging system according to an embodiment of the present invention.
2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.
3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.
4 is a block diagram illustrating a structure of a wireless power transmission apparatus according to an embodiment of the present invention.
5 is a block diagram illustrating a structure of a wireless power transmission apparatus according to another embodiment of the present invention.
6 is a block diagram illustrating the structure of a voltage blocking circuit assembly according to an embodiment of the present invention.
7 is a block diagram illustrating a detailed configuration of a voltage blocking circuit assembly according to an embodiment of the present invention.
8 is an equivalent circuit diagram of a first shut-off circuit for under-voltage shutdown according to an embodiment of the present invention.
9 is an equivalent circuit diagram of a first shut-off circuit for under-voltage shutdown according to another embodiment of the present invention.
10 is an equivalent circuit diagram of a second shut-off circuit for high-voltage shutdown according to an embodiment of the present invention.
11 is a block diagram illustrating a structure of a wireless power transmission apparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and various methods to which embodiments of the present invention 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.

In the description of the embodiment, in the case where it is described as being formed "above" or "below" each element, the upper or lower (lower) And that at least one further component is formed and arranged between the two components. Also, in the case of "upper (upper) or lower (lower)", it may include not only the upward direction but also the downward direction based on one component.

In the description of the embodiments, an apparatus for transmitting wireless power on a wireless power 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, and the like are used in combination. Also, for the sake of convenience of explanation, it is to be understood that a wireless power receiving apparatus, a wireless power receiving apparatus, a wireless power receiving apparatus, a wireless power receiving apparatus, a receiving terminal, a receiving side, a receiving apparatus, Etc. may be used in combination.

The transmitter according to the present invention may be configured as a pad, a cradle, an access point (AP), a small base station, a stand, a ceiling, a floor, And may transmit wireless power to the power receiving device. To this end, the transmitter may comprise at least one radio power transmission means. Here, the radio power transmission means may be various non-electric power transmission standards based on an electromagnetic induction system in which a magnetic field is generated in a power transmitting terminal coil and charged using an electromagnetic induction principle in which electricity is induced in a receiving terminal coil under the influence of the magnetic field. For example, the wireless power transmission means may include an electromagnetic induction wireless charging technique as defined in a wireless charging technology standard framework such as Wireless Power Consortium (WPC), Qi, and Power Matters Alliance (PMA).

Also, a receiver according to an embodiment of the present invention may include at least one wireless power receiving means and may receive wireless power from two or more transmitters at the same time. Here, the wireless power receiving means may include, but is not limited to, an electromagnetic induction wireless charging technique defined by Wireless Power Consortium (WPC), Power Matters Alliance (PMA), which is a wireless charging technology standard mechanism.

A wireless power receiver according to the present invention may be mounted on one side of a transportation device, but is not limited thereto, and may be a device equipped with wireless power receiving means according to the present invention to charge a battery.

The wireless power transmitter and the wireless power receiver according to the present invention can be classified into a class and a category, respectively.

The type and characteristics of the wireless power transmitter can be largely identified by the following three parameters.

First, the wireless power transmitter can be identified by a rating determined according to the intensity of the maximum power applied to the resonant circuit.

Here, the rank of the wireless power transmitter is determined by the maximum power of the power (PTX_IN_COIL) applied to the resonance circuit by the predefined maximum input power (PTX_IN_MAX) according to the rating specified in the wireless power transmitter class table - Can be determined. Here, PTX_IN_COIL may be an average real number value calculated by dividing the product of the voltage V (t) and the current I (t) applied to the resonance circuit for a unit time by the unit time.

Class Maximum Input Power Min Category
Support Requirements Support Max
Number of devices Class 1 2W 1 x grade 1 1 x grade 1 Grade 2 10W 1 x Grade 3 2 x Grade 2 Grade 3 16W 1 x rating 4 2 x Grade 3 Grade 4 33W 1 x Grade 5 3 x Grade 3 Rating 5 50W 1 x grade 6 4 x Grade 3 Rating 6 70W 1 x grade 6 5 x Grade 3

The grades disclosed in Table 1 above are merely one example, and new grades may be added or deleted. It should also be noted that the values for the maximum input power per class, the minimum category support requirements, and the maximum number of devices that can be supported may vary depending on the use, configuration, and implementation of the wireless power transmitter.

For example, referring to Table 1, if the maximum value of the power (PTX_IN_COIL) applied to the resonance circuit is greater than or equal to the PTX_IN_MAX value corresponding to the class 3 and smaller than the PTX_IN_MAX value corresponding to the class 4, Can be determined as a grade 3.

Second, the wireless power transmitter may be identified according to the Minimum Category Support Requirements corresponding to the identified class.

Here, the minimum category support requirement may be a supportable number of wireless power receivers corresponding to the highest level category of the wireless power receiver category that the wireless power transmitter of the corresponding class can support. That is, the minimum category support requirement may be the minimum number of maximum category devices that the wireless power transmitter can support. At this time, the wireless power transmitter may support all categories of wireless power receivers corresponding to less than the maximum category according to the minimum category requirement.

However, if the wireless power transmitter can support a wireless power receiver of a category higher than the category specified in the minimum category support requirement, then the wireless power transmitter may not limit its support of the wireless power receiver.

For example, referring to Table 1 above, a Class 3 wireless power transmitter should support at least one Category 5 wireless power receiver. Of course, in this case, the wireless power transmitter may support a wireless power receiver that falls into a category lower than the category level corresponding to the minimum category support requirement.

It should also be noted that the wireless power transmitter may support a wireless power receiver with a higher level category if it is determined that it is capable of supporting a higher level category than the category corresponding to the minimum category support requirement.

Third, the wireless power transmitter may be identified by the maximum number of supportable devices corresponding to the identified class. Here, the maximum number of devices that can be supported may be identified by the maximum number of supportable wireless power receivers corresponding to the lowest-level category among the categories that can be supported by the rating - hereinafter simply referred to as the maximum number of supportable devices .

For example, referring to Table 1 above, a Class 3 wireless power transmitter should be able to support up to two wireless power receivers with a minimum category of 3.

However, when the wireless power transmitter can support more than the maximum number of devices corresponding to its own rating, it does not limit to support more than the maximum number of devices.

The wireless power transmitter according to the present invention must be capable of performing at least the wireless power transmission within the available power up to the number defined in Table 1 if there is no particular reason not to allow the power transmission request of the wireless power receiver.

In one example, the wireless power transmitter may not accept a power transfer request for the wireless power receiver if there is not enough available power to accommodate the power transfer request. Alternatively, the power adjustment of the wireless power receiver can be controlled.

In another example, the wireless power transmitter may not accept a power transfer request of the wireless power receiver if the number of acceptable wireless power receivers is exceeded upon accepting the power transfer request.

In another example, the wireless power transmitter may not accept a power transfer request for the wireless power receiver if the category of the wireless power receiver requesting power transmission exceeds a category level that is supported in its rating.

In another example, a wireless power transmitter may not accept a power transfer request from the wireless power receiver if the internal temperature exceeds a reference value.

The types and characteristics of the wireless power receiver will be described below.

The average output voltage PRX_OUT of the receiver may be a real value calculated by dividing the product of the voltage V (t) output by the rectifier for a unit time and the current I (t) by the unit time.

The category of the wireless power receiver can be defined based on the maximum output voltage (PRX_OUT_MAX) of the rectifier, as shown in Table 2 below.

category
(Category) Maximum Input Power Application example Category 1 TBD Bluetooth Handset Category 2 3.5 W Feature phone Category 3 6.5 W Smartphone Category 4 13W Tablet Category 5 25W Small laptop Category 6 37.5 W laptop Category 6 50W TBD

For example, if the charging efficiency at the bottom stage is 80% or more, the category 3 wireless power receiver can supply 5 W of power to the charging port of the load.

The classes and categories disclosed in the above Tables 1 and 2 are only one example, and some classes and categories may be added or deleted. In addition, examples of maximum input power and application by class and category shown in Tables 1 and 2 above may be changed according to usage, shape, implementation type as well as wireless charging standard applied to wireless power transmitter and wireless power receiver .

1 is a block diagram illustrating a wireless charging system according to an embodiment of the present invention.

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 state information and control information exchanged between the transmitting and receiving ends include information for identifying the category of the wireless power receiver, information for identifying the current power receiving state of the wireless power receiver, information about whether or not the overvoltage protection function is mounted, Software version information mounted on the power receiver, power control request information, and the like.

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 an embodiment of the present invention 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.

In particular, the wireless power transmitting terminal 10 according to an embodiment of the present invention can transmit a predetermined packet indicating whether or not to support fast charging to the wireless power receiving terminal 20. The wireless power receiving terminal 20 can inform the electronic device 30 of the connected wireless power transmitting terminal 10 when it is confirmed that it supports the fast charging mode. The electronic device 30 may indicate that fast charging is possible through a predetermined display means, which may be, for example, a liquid crystal display.

Also, the user of the electronic device 30 may select the predetermined fast charge request button displayed on the liquid crystal display means to control the wireless power transmitting terminal 10 to operate in the fast charge mode. In this case, the electronic device 30 can transmit a predetermined fast charge request signal to the wireless power receiving terminal 20 when the quick charge request button is selected by the user. The wireless power receiving terminal 20 may generate a charging mode packet corresponding to the received fast charging request signal and transmit the same to the wireless power transmitting terminal 10 to switch the general low power charging mode to the fast charging mode.

2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.

For example, as shown in 200a, the wireless power receiving terminal 20 may include a plurality of wireless power receiving devices, and a plurality of wireless power receiving devices may be connected to one wireless power transmitting terminal 10, Charging may also be performed. At this time, the wireless power transmitting terminal 10 can distribute power to a plurality of wireless power receiving apparatuses in a time division manner, but it is not limited thereto. In another example, the wireless power transmitting terminal 10 can distribute power to a plurality of wireless power receiving apparatuses using different frequency bands allocated to the wireless power receiving apparatuses.

At this time, the number of wireless power receiving apparatuses connectable to one wireless power transmitting apparatus 10 is set to at least one of the required power amount for each wireless power receiving apparatus, the battery charging state, the power consumption amount of the electronic apparatus, Can be determined adaptively based on

As another example, as shown in 200b, the wireless power transmitting terminal 10 may be composed of a plurality of wireless power transmitting apparatuses. In this case, the wireless power receiving terminal 20 may be connected to a plurality of wireless power transmission apparatuses at the same time, and may simultaneously receive power from connected wireless power transmission apparatuses to perform charging. At this time, the number of wireless power transmission apparatuses connected to the wireless power receiving terminal 20 is adaptively set based on the required power amount of the wireless power receiving terminal 20, the battery charging status, the power consumption amount of the electronic apparatus, Can be determined.

3 is a diagram for explaining a sensing signal transmission procedure in a wireless charging system according to an embodiment of the present invention.

As an example, the wireless power transmitter may be equipped with three transmit coils 111, 112, 113. Each of the transmission coils may be disposed such that a portion of the transmission coils overlaps with the other transmission coils. However, this is merely an example, and the transmission coils may be disposed without overlapping one another or with one transmission coil.

The wireless power transmitter sequentially transmits predetermined sensing signals 117, 127 (e.g., digital ping) for sensing the presence of a wireless power receiver through each transmit coil in a predefined sequence.

3, the wireless power transmitter sequentially transmits the detection signal 117 when the primary sensing signal transmission procedure shown in the reference numeral 110 is started, and outputs a predetermined response signal - For example, a signal strength indicator 116 or a signal strength packet may be referred to as a signal strength indicator for convenience of explanation. The received transmission coils 111 and 112 can be identified. Subsequently, the wireless power transmitter sequentially transmits the detection signal 127 when the secondary detection signal delivery procedure shown in the reference numeral 120 is started, and when the signal strength indicator 126 indicates that the power of the transmission coils 111 and 112 It is possible to control the transmission efficiency (or charging efficiency) - that is, the alignment state between the transmitting coil and the receiving coil - to identify a good transmitting coil and to allow power to be delivered through the identified transmitting coil, have.

As shown in FIG. 3, the reason why the wireless power transmitter performs the two detection signal transmission procedures is to more accurately identify to which transmission coil the reception coil of the wireless power receiver is well aligned.

If the signal strength indicators 116 and 126 are received at the first transmission coil 111 and the second transmission coil 112 as shown in the aforementioned numerals 110 and 120 of FIG. 3, Selects a transmission coil having the best alignment based on the received signal strength indicator 126 in each of the first transmission coil 111 and the second transmission coil 112 and performs wireless charging using the selected transmission coil .

4 is a block diagram illustrating a structure of a wireless power transmission apparatus according to an embodiment of the present invention.

4, the wireless power transmission apparatus 400a may include a power source 410, a voltage cutoff circuit assembly 420, an inverter 430, a resonant circuit 440, and a controller 450. Referring to FIG. Here, the controller 450 may be implemented in the form of a microprocessor and may control the overall operation of the wireless power transmitter 440a.

The voltage blocking circuit assembly 420 may control the inverter 430 to supply a certain range of voltages to the inverter 430 for protection of the inverter 430 and the receiver.

For example, the Qi standard, one of the wireless power transmission technology standards, recommends that the output voltage level during mid-power transmission be maintained between 11.4V and 12.6V.

If the output voltage level is 15V or higher, the electronic equipment equipped with the wireless power receiver and / or the wireless power receiver may be damaged.

Also, if the output voltage level is below 10V, a high current may flow through the resonant circuit 440 to meet the amount of power required by the wireless power receiver. In this case, the wireless power transmitter may be damaged.

Therefore, it is very important to keep the output voltage level of the wireless power transmission device within a certain range in order to prevent device breakage.

The inverter 430 can convert the DC / DC converted DC power into an AC power signal based on the reference AC signal. At this time, the frequency of the reference AC signal - that is, the operating frequency - can be changed dynamically according to the control signal of the controller 450. The wireless power transmitter 400a may adjust the operating frequency to adjust the intensity of the power transmitted through the resonant circuit 440. [ In one example, the controller 450 may receive the power reception status information and / or power control signal of the wireless power receiver via the communication means provided and may receive the power control information based on the received power reception status information and / So that the operating frequency can be determined. For example, the power reception status information may include, but is not limited to, the intensity information of the rectifier output voltage, the intensity information of the current applied to the reception coil, and the like. The power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like. Here, the communication means may include at least one of an antenna, a modulator and a demodulator for short-range wireless communication or in-band communication. Here, the modulator and the demodulator may be integrally implemented in the controller 450, but this is merely one embodiment, and may be separately implemented in the form of a modem, a digital signal processor (DSP), an ASIC, ).

The inverter 430 may include at least one of a half bridge inverter and a full bridge inverter. However, the present invention is not limited thereto, and a circuit configuration capable of converting DC power into AC power having a specific operating frequency is sufficient.

The resonance circuit 440 may be configured to include an LC circuit for transmitting a wireless power signal. The number of inductors included in the resonance circuit 440, that is, the number of transmission coils may be plural.

The voltage blocking circuit assembly 420 may be configured such that not only the voltage applied from the power source 410 is an overvoltage but also the power supplied to the inverter 430 is cut off even when the voltage is low. 6, a voltage blocking circuit assembly 420 includes a first blocking circuit 610 for blocking a low voltage and a second blocking circuit 610 for blocking a high voltage, .

The voltage blocking circuit assembly 420 according to the present embodiment can be implemented using general circuit elements without including a microprocessor, thereby reducing cost. That is, the voltage interrupting circuit assembly 420 according to the present embodiment controls the voltage supplied to the inverter 430 by using an analog circuit element instead of being controlled by software.

If an overvoltage is applied to the inverter 430, the wireless power receiver may be damaged. In addition, when a low voltage is applied to the inverter 430, the intensity of the current flowing through the resonance circuit 440 for the specific power transmission may be increased, thereby damaging the wireless power transmitter. Therefore, it is important to keep the voltage applied to the inverter 430 within the normal operating range.

The voltage supplied from the power source 410 may not be stable. In one example, when a wireless power transmitter is mounted in a vehicle, wireless charging can be accomplished using vehicle battery power. In this case, the output voltage of the vehicle battery may fluctuate greatly due to a vehicle start-up or other external influences. The voltage blocking circuit assembly 420 according to the present invention is advantageous in that damage to the wireless power transmitter and the wireless power receiver can be prevented even when the voltage applied from the power source 410 is abruptly changed.

In the case of a conventional wireless charging system, the wireless power transmitter blocks or reduces power transmitted through the resonant circuit 440 to prevent equipment damage due to overvoltage when a predetermined status message indicating that an overvoltage is detected is received from the wireless power receiver . However, there is a disadvantage in that damage to the transmitter due to low voltage can not be prevented. In addition, the conventional wireless power transmitter has a disadvantage in that the overvoltage can not be prevented in advance because the overvoltage is cut off according to the feedback information from the wireless power receiver.

However, since the wireless power transmitter according to the present invention includes the voltage blocking circuit assembly 420, it is possible to prevent breakage of the transmitter due to low voltage and to prevent the damage of the receiver due to overvoltage.

5 is a block diagram illustrating a structure of a wireless power transmission apparatus according to another embodiment of the present invention.

As shown in FIG. 5, the wireless power transmission apparatus 400b according to the present embodiment may further include a DC-DC converter 460 in the configuration of FIG.

In one example, the intensity of the power transmitted through the resonant circuit 440 can be adjusted by controlling the output voltage of the DC-DC converter 460.

The DC-DC converter 460 may perform a function of converting the DC power supplied from the power source 410 to DC power of a specific intensity according to a control signal of the controller 450. [

The intensity of the power transmitted through the resonant circuit 440 may be a phase or a duty of a pulse width modulation (PWM) signal supplied from the controller 450 to the inverter 430, And may be controlled by adjusting a duty rate.

DC-to-DC converter 460 has a large reliability deviation with respect to the output level depending on the manufacturer and the unit price. Therefore, there is a problem that only the control of the controller 450 can not be completely trusted.

The voltage blocking circuit assembly 420 according to the present invention can block overvoltage and undervoltage caused by a malfunction of the DC-DC converter 460.

6 is a block diagram illustrating the structure of a voltage blocking circuit assembly according to an embodiment of the present invention.

Referring to FIG. 6, the voltage blocking circuit assembly 420 may include a first blocking circuit 610 and a second blocking circuit 620.

The input terminal of the first blocking circuit 610 may be connected to the power source 410 or the DC-DC converter 460 and the output terminal of the second blocking circuit 620 may be connected to the inverter 430.

The first blocking circuit 610 may block power from being delivered to the second blocking circuit 620 when a voltage below a predefined level is sensed. Therefore, when the voltage lower than the reference value is supplied from the power source 410 or the DC-DC converter 460, the first blocking circuit 610 can control the power to not be transmitted to the inverter 430.

The second blocking circuit 620 may control the power not to be transmitted to the inverter 430 when a voltage higher than a predetermined level is detected. Thus, the second isolation circuit 620 can in advance prevent the high voltage from being supplied to the inverter 430 and the wireless power receiver.

7 is a block diagram illustrating a detailed configuration of a voltage blocking circuit assembly according to an embodiment of the present invention.

7, the first blocking circuit 610 may include a voltage dividing circuit 611, a comparing circuit 612, a reference voltage supplying circuit 613, and a first blocking switch 614.

The second blocking circuit 620 may include a high voltage sensing circuit 630, a switch control circuit 640, and a second blocking switch 650.

Hereinafter, the configurations of the first blocking circuit 610 and the second blocking circuit 620 will be described in detail.

The voltage distribution circuit 611 can distribute the voltage supplied from the power supply 410 or the DC-DC converter 460 to the comparison circuit 612. Hereinafter, the voltage supplied from the voltage distribution circuit 611 to the comparison circuit 612 will be referred to as a comparator input voltage V_comp_input.

The reference voltage supply circuit 613 can supply the reference voltage V_ref set in advance to the comparison circuit 612.

The comparison circuit 612 can compare the input voltage of the comparator with the reference voltage to determine whether a low voltage is being supplied.

The comparator circuit 612 can output the predetermined control signal to control the first blocking switch 614 so that the low voltage is not transmitted to the second blocking circuit 620 when the low voltage is supplied.

The first blocking switch 614 controls the switch provided according to the output of the comparison circuit 612 to transmit power to the second blocking circuit 610 or to supply power to the second blocking circuit 610 Can be blocked. For example, when the comparator input voltage is greater than the reference voltage, the output of the comparator circuit 612 goes HIGH to transmit power to the second blocking circuit 610. If the comparator input voltage is less than the reference voltage, The output of the second blocking circuit 610 becomes LOW and the power supply to the second blocking circuit 610 can be interrupted.

The high voltage sensing circuit 630 of the second blocking circuit 620 can drive the switch control circuit 640 when the intensity of the voltage supplied from the first blocking circuit 610 exceeds a predetermined high voltage determination reference value. At this time, the switch control circuit 640 may control the second cutoff switch 650 so that the electric power supplied from the first cutoff circuit 610 is not transmitted to the inverter 430. Of course, if the voltage supplied from the first blocking circuit 610 is lower than a predetermined high voltage judgment reference value, the power supplied from the first blocking circuit 610 can be bypassed to the inverter 430.

8 is an equivalent circuit diagram of a first shut-off circuit for under-voltage shutdown according to an embodiment of the present invention.

8, the voltage divider circuit 611 of the first blocking circuit 610 includes two resistors R1 and R2 connected in series and a comparator input voltage Q2, which is branched between the two resistors and connected to the comparing circuit 612. [ And a line. Here, the comparator input voltage line may be connected to the positive input terminal of the comparator circuit 612.

The negative input terminal of the comparison circuit 612 may be connected to the output terminal of the reference voltage supply circuit 613.

The output of the comparison circuit 612 is connected to the first blocking switch 614.

If the comparator input voltage V_comp_input is greater than the reference voltage V_ref, the output of the comparison circuit 612 goes HIGH, otherwise the output of the comparison circuit 612 can be LOW. Note that HIGH corresponds to the comparator input voltage and LOW can be OV, but it is not so limited and different values may be output depending on the comparator design.

The first blocking switch 614 may be configured to include two transistors TR1 and TR2 and one resistor R3. For example, TR1 and TR2 may be implemented as an N-channel MOSFET (Metal Oxide Silicon Field Effect Transistor) and a P-channel MOSFET, respectively.

The operation of TR1 is controlled according to the output of the comparison circuit 612, and the operation of TR2 can be controlled according to the operation of TR1.

For example, if the output of comparator circuit 612 is HIGH-for example, can be a comparator input voltage, the N-channel MOSFET TR1 is switched on and accordingly the P-channel MOSFET TR2 can also be switched on . That is, the first blocking switch 614 may be operated so that the power supplied from the power source 410 or the DC-DC converter 460 is transmitted to the second blocking circuit 620.

In another example, if the output of the comparison circuit 612 is LOW - for example, 0V - then the N-channel MOSFET TR1 is switched off and accordingly the P-channel MOSFET TR2 can also be switched off. That is, the first disconnecting switch 614 can block the power supplied from the power source 410 or the DC-DC converter 460 from being transmitted to the second blocking circuit 620.

9 is an equivalent circuit diagram of a first shut-off circuit for under-voltage shutdown according to another embodiment of the present invention.

As shown in Fig. 9, the MOSFET constituting the first blocking switch 614 of Fig. 8 described above according to the purpose and purpose of the wireless power transmitter has the bipolarity corresponding to the corresponding MOSFET type And may be replaced with a Bipolar Junction Transistor (BJT).

Referring to reference numeral 910, the first BJT and the second BJT may be implemented as an NPN type and a PNP type, respectively.

10 is an equivalent circuit diagram of a second shut-off circuit for high-voltage shutdown according to an embodiment of the present invention.

Referring to FIG. 10, the second blocking circuit 620 may include a high voltage sensing circuit 630, a switch control circuit 640, and a second blocking switch 650.

The high voltage sensing circuit 630 may be implemented as a Zener diode. Here, when the zener diode is applied with a reverse voltage higher than the zener voltage or the breakdown voltage, a reverse current flows. Here, the breakdown voltage of the zener diode may be set to a predetermined high voltage judgment reference voltage. The switch control circuit 640 may be configured to include one resistor R6 (641) and one transistor TR3 (642). It is possible to prevent the TR3 642 from being damaged by the reverse current flowing through the Zener diode 630 when the breakdown voltage is exceeded through the resistor R6 (641).

If there are a plurality of breakdown voltages to be set, a plurality of zener diodes having different breakdown voltages may be provided in the high voltage detection circuit 630. In this case, the controller 450 can activate only the Zener diode according to the breakdown voltage to be set. In one example, the power level required by the wireless power receiver can be changed dynamically according to the category and requirements of the wireless power receiver. Controller 450 may adaptively determine the breakdown voltage in accordance with the category and power requirements of the wireless power receiver and may activate a zener diode operating on that breakdown voltage based on the determined breakdown voltage.

TR3 according to one embodiment may be implemented as a BJT, but it is not limited thereto, and other equivalent transistors may be used.

The second blocking switch 650 includes two resistors R4 651 and R5 652 for two voltage distributions and two small outline package (MOSFET) type MOSFETs TR4 653 and TR5 654, .

When the TR3 642 is switched on by the reverse current flowing through the Zener diode 630, the TR4 653 and the TR5 654 are switched off and the power supplied from the first blocking circuit 620 can be cut off .

On the other hand, if the voltage applied to the Zener diode 630 is below the breakdown voltage, the TR5 654 is switched on so that the power supplied from the first blocking circuit 620 can be transmitted to the inverter 430. [

11 is a block diagram illustrating a structure of a wireless power transmission apparatus according to another embodiment of the present invention.

Referring to FIG. 11, the wireless power transmission apparatus 400c according to the present embodiment may further include a blocking circuit control switch 470 in the configuration of FIG.

The cut-off control circuit switch 470 may transmit the power supplied from the DC-DC converter 460 to the voltage blocking circuit assembly 420 or to the inverter 430 according to the control signal of the controller 450.

In one example, the controller 450 may be coupled to the resonant circuit 440 via a sensor (not shown) provided in the wireless power transmitter 440c or to a DC-DC converter (not shown) if the measured temperature at a particular location in the device exceeds a predetermined threshold 460 may be transmitted to the voltage blocking circuit assembly 420.

In another example, the controller 450 may control the power supplied from the DC-DC converter 460 to be delivered to the voltage blocking circuit assembly 420 when the intensity of the requested power of the wireless power receiver exceeds a predetermined reference value .

In another example, the controller 450 may control the power supplied from the DC-DC converter 460 to be delivered to the voltage blocking circuit assembly 420 when the power reception level of the wireless power receiver exceeds a predetermined reference value .

In another example, the controller 450 calculates the path loss of the AC power signal transmitted through the resonance circuit 440, and supplies the path loss from the DC-DC converter 460 when the calculated path loss is out of a predetermined reference range May be controlled to be transmitted to the voltage blocking circuit assembly 420. For example, if the power conversion operation in the DC-DC converter 460 under control of the controller 450 is not normal, the path loss in the radio section may deviate from the predetermined reference range.

In another example, the controller 450 may receive predetermined status information from the wireless power receiver indicating whether the overvoltage shutdown function is mounted or not. At this time, when the overvoltage shutdown function is installed or activated in the wireless power receiver, the controller 450 controls the power supplied from the DC-DC converter 460 to the inverter 430 directly without passing through the voltage blocking circuit assembly 420 The blocking circuit control switch 470 can be controlled.

On the other hand, when the overvoltage cutoff function is not mounted or deactivated in the wireless power receiver, the controller 450 switches the cutoff circuit control switch (or the cutoff circuit control switch) so that the power supplied from the DC / DC converter 460 is transmitted to the voltage cutoff circuit assembly 420 470).

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

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 (19)

A voltage blocking circuit assembly provided in a wireless power transmission apparatus for controlling power supply to an inverter,
A first blocking circuit for comparing the input voltage with a predetermined reference voltage to cut off power supply to the inverter when a low voltage is sensed; And
And a second blocking circuit for blocking power supply to the inverter when the voltage supplied from the first blocking circuit exceeds a predetermined threshold voltage,
And the voltage blocking circuit assembly. The method according to claim 1,
The first blocking circuit
A voltage distribution circuit for distributing a voltage applied from a power source or a DC-DC converter to provide the input voltage;
A reference voltage supply circuit for supplying the reference voltage;
A comparison circuit for comparing the input voltage and the reference voltage; And
A first blocking switch for controlling power supply to the second blocking circuit in accordance with the output of the comparing circuit,
And the voltage blocking circuit assembly. 3. The method of claim 2,
Wherein power is supplied to the second blocking circuit if the input voltage is less than the reference voltage and to the second blocking circuit if the input voltage is greater than the reference voltage. The method of claim 3,
Wherein the first blocking switch includes a first transistor connected to an output terminal of the comparison circuit and a second transistor connected to a drain of the first transistor, and when the input voltage is smaller than the reference voltage, Wherein all the switches of the second transistor are turned off to cut off power supply to the second blocking circuit. The method according to claim 1,
The second blocking circuit
A high voltage sensing circuit for sensing whether a voltage supplied from the first blocking circuit is higher than a predetermined threshold voltage;
A second blocking switch for controlling power supply to the inverter; And
A switch control circuit for controlling the second cut-off switch to cut off power supplied to the inverter when the detected voltage is equal to or higher than the threshold voltage,
And the voltage blocking circuit assembly. 6. The method of claim 5,
Wherein the high voltage sensing circuit is a Zener diode that supplies a reverse current to the switch control circuit at the threshold voltage. The method according to claim 6,
The switch control circuit
A third transistor operated by the reverse current; And
A resistor disposed between the third transistor and the Zener diode for preventing the third transistor from being damaged by the reverse current,
And the voltage blocking circuit assembly. 8. The method of claim 7,
And the second blocking switch includes a fourth transistor and a fifth transistor that are turned off when the third transistor is switched on to block the power supplied from the first blocking circuit from being transmitted to the inverter. assembly. A voltage blocking circuit assembly for sensing a DC voltage supplied from a power source or a DC-DC converter to cut off predetermined low voltage and high voltage;
An inverter receiving the DC power from the voltage blocking circuit assembly and converting the DC power into an AC power signal; And
A resonance circuit for wirelessly transmitting the AC power signal
And a second power supply. 10. The method of claim 9,
A controller; And
And a blocking circuit control switch for switching the power supplied from the power source or the DC-DC converter to any one of the voltage blocking circuit assembly and the inverter according to a control signal of the controller
Wherein the wireless power transmission device further comprises: 11. The method of claim 10,
Based on at least one of information on the power reception class collected from the wireless power receiver, information on the strength of the requested power, information on the strength of the received power, and information on whether or not the overvoltage blocking function is activated, And controls the control switch. 10. The method of claim 9,
The voltage blocking circuit assembly
A first blocking circuit that compares an input voltage with a predetermined reference voltage to cut off power supply to the inverter when the low voltage is sensed; And
And a second blocking circuit for blocking power supply to the inverter when the voltage supplied from the first blocking circuit exceeds a predetermined threshold voltage,
And a second power supply. 13. The method of claim 12,
The first blocking circuit
A voltage divider circuit for dividing a DC voltage applied from the power source or the DC-DC converter to provide the input voltage;
A reference voltage supply circuit for supplying the reference voltage;
A comparison circuit for comparing the input voltage and the reference voltage; And
A first blocking switch for controlling power supply to the second blocking circuit in accordance with the output of the comparing circuit,
And a second power supply. 14. The method of claim 13,
Wherein power is supplied to the second blocking circuit when the input voltage is less than the reference voltage and power is supplied to the second blocking circuit if the input voltage is greater than the reference voltage. 15. The method of claim 14,
Wherein the first blocking switch includes a first transistor connected to an output terminal of the comparison circuit and a second transistor connected to a drain of the first transistor, and when the input voltage is smaller than the reference voltage, And all of the switches of the second transistor are turned off to cut off power supply to the second blocking circuit. 13. The method of claim 12,
The second blocking circuit
A high voltage sensing circuit for sensing whether a voltage supplied from the first blocking circuit is higher than a predetermined threshold voltage;
A second blocking switch for controlling power supply to the inverter; And
A switch control circuit for controlling the second cut-off switch to cut off power supplied to the inverter when the detected voltage is equal to or higher than the threshold voltage,
And a second power supply. 17. The method of claim 16,
Wherein the high voltage sensing circuit is a Zener diode that supplies a reverse current to the switch control circuit at the threshold voltage. 18. The method of claim 17,
The switch control circuit
A third transistor operated by the reverse current; And
A resistor disposed between the third transistor and the Zener diode for preventing the third transistor from being damaged by the reverse current,
And a radio frequency generator. 19. The method of claim 18,
Wherein the second blocking switch includes a fourth transistor and a fifth transistor that are switched off when the third transistor is switched on to block the power supplied from the first blocking circuit from being transferred to the inverter. Device.

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