Multi-coil wireless charger

Abstract

A wireless charger includes a plurality of transmitter coils, first and second drivers, and a controller. The transmitter coils are arranged adjacent to and / or overlapping each other. The first driver is coupled with at least one of the transmitter coils to drive the transmitter coil through a first channel to communicate with and / or provide energy to a receiver device. The second driver is coupled with at least one other of the transmitter coils to drive the transmitter coil through a second channel to communicate with and / or provide energy to the receiver device. The controller is coupled to the first and second drivers and enables only one of the first and second drivers in a first phase.

Description

Technical Field

[0001] This invention relates to wireless chargers. Specifically, this invention relates to avoiding interference between coils in a multi-coil wireless charger. Background Technology

[0002] Wireless chargers are convenient to use because they allow electronic devices to charge without being plugged into a power outlet. Wireless chargers are developed to charge multiple devices (receivers) simultaneously. In operation, the receiver is placed on the corresponding coil of the charger, and the coil transfers energy to the receiver. The coil is also used for communication between the charger and the receiver. However, coils can interfere with the communication between adjacent coils and their receivers. Therefore, managing interference between coils is advantageous. Summary of the Invention

[0003] This summary is provided to illustrate selected simplified portions of the concepts detailed in the following detailed description. This summary is not intended to identify key or essential features of the claims, nor is it intended to limit the scope of the claims.

[0004] According to one embodiment, a wireless charger is provided, comprising:

[0005] Multiple transmitter coils are arranged adjacent to and / or overlapping each other;

[0006] A first driver coupled to at least one of a plurality of transmitter coils to drive the at least one coupled transmitter coil to communicate with a receiver device and / or provide power to the receiver device through a first channel;

[0007] A second driver coupled to at least one of a plurality of transmitter coils to drive the at least one coupled transmitter coil to communicate with the receiver device and / or supply power to the receiver device through a second channel;

[0008] A controller connected to the first drive and the second drive, wherein the controller is configured to enable only one of the first drive and the second drive at a time during the first phase.

[0009] For example, the controller is configured to allow a transmitter coil coupled to an enabled driver to send a first signal in a first phase, while simultaneously muting transmitter coils coupled to other drivers.

[0010] For example, in response to a signal received from the receiver device in the first phase, the controller is configured to identify and drive a transmitter coil coupled to an enabled driver to communicate with and / or supply power to the receiver device in the second phase, and to disable a transmitter coil immediately adjacent to the identified transmitter coil.

[0011] For example, the controller is configured to disable the transmitter coil that is connected to the same driver as the identified transmitter coil in the second stage.

[0012] For example, the identified transmitter coil and the disabled transmitter coil immediately adjacent to the identified transmitter coil are coupled to different drivers.

[0013] For example, the controller is configured to provide PWM signals for synchronizing the transmitter coils coupled to different drivers.

[0014] For example, the controller is configured to provide a first PWM signal to a transmitter coil coupled to a first driver and a second PWM signal to a transmitter coil coupled to a second driver.

[0015] For example, the controller synchronizes the PWM signals by having the rising edge of the first PWM signal occur simultaneously with the rising edge of the second PWM signal.

[0016] For example, the controller is further configured to use PWM signals to generate power signals and data packets communicated by the transmitter coil.

[0017] For example, the controller is further configured to control the rising edge of the first PWM signal at the start of the power signal at the rising edge of the second PWM signal.

[0018] For example, the controller is further configured to control the rising edge of the first PWM signal at the end of the data packet to the rising edge of the second PWM signal.

[0019] According to another embodiment, a wireless charger is provided, comprising:

[0020] A plurality of transmitter coils configured to communicate with and transmit energy to a receiver device, wherein the plurality of transmitter coils include at least one first transmitter coil and at least one second transmitter coil overlapping the first transmitter coil; and

[0021] A controller coupled to a plurality of transmitter coils, wherein the controller is configured to mute a second transmitter coil when the first transmitter coil transmits a signal in response to the first transmitter coil transmitting a signal.

[0022] For example, the first transmitter coil and the second transmitter coil are coupled to different drivers to communicate through different channels.

[0023] For example, multiple transmitter coils are configured to transmit FSK data packets generated by modulating PWM signals, as well as transmit power signals.

[0024] For example, the controller is configured to provide PWM signal synchronization for the non-silent transmitter coils in response to the completion of each FSK packet transmission by the first transmission in the non-silent transmitter coils other than the silent second transmitter coil, the synchronization being achieved by:

[0025] The first PWM signal provided for the first non-mute transmitter coil is configured such that the rising edge of the first PWM signal coincides with the rising edge of the PWM signal provided for the other non-mute transmitter coils.

[0026] For example, the controller is configured to synchronize a PWM signal provided for a non-mute transmitter coil other than the mute second transmitter coil, the synchronization being achieved through:

[0027] At the beginning of the first power transmission signal for the non-silent transmitter coil, the first PWM signal for the first non-silent transmitter coil is configured to occur simultaneously with the rising edge of the PWM signal for the other non-silent transmitter coils.

[0028] According to another embodiment, a wireless charger is provided, comprising:

[0029] Multiple transmitter coils arranged in an array are configured to communicate with and / or supply power to the receiver device;

[0030] A controller coupled to multiple transmitter coils, wherein the controller is configured to generate FSK data packets from PWM signals and drive multiple transmitter coils to transmit FSK data packets to communicate with a receiver device;

[0031] The controller is configured to synchronize the PWM signals provided for multiple transmitter coils, wherein the synchronization is achieved by: after the FSK data packet is sent, the rising edge of the PWM signal for one of the multiple transmitter coils occurs simultaneously with the rising edge of the PWM signal for the other transmitter coils.

[0032] For example, the controller is further configured to synchronize the PWM signals provided for multiple transmitter coils, wherein the synchronization is achieved by: before the power signal is transmitted, the rising edge of the PWM signal for one of the multiple transmitter coils occurs simultaneously with the rising edge of the PWM signal for the other transmitter coils.

[0033] For example, multiple transmitter coils include:

[0034] First transmitter coil; and

[0035] At least one second transmitter coil overlapping with the first transmitter coil; and

[0036] The wireless charger further includes:

[0037] A first driver coupled to a first transmitter coil to drive the first transmitter coil to communicate through a first channel; and

[0038] A second driver coupled to the at least one second transmitter coil to drive the at least one second transmitter coil to communicate through the second channel;

[0039] The controller is further configured to control a first driver to drive a first transmitter coil for signal communication, and simultaneously control a second driver to not drive the at least one second transmitter coil for signal communication.

[0040] For example, multiple transmitter coils include:

[0041] First transmitter coil; and

[0042] At least one second transmitter coil overlapping with the first transmitter coil;

[0043] The wireless charger further includes:

[0044] A driver coupled to a first transmitter coil and the at least one second transmitter coil to drive the first transmitter coil and the at least one second transmitter coil to communicate through a first channel, wherein the controller is configured to drive the first transmitter coil and the at least one second transmitter coil to communicate signals alternately. Attached Figure Description

[0045] To enable a more concrete understanding of the foregoing contents of this invention, further detailed description of the invention can be obtained by referring to embodiments, some of which are illustrated in the accompanying drawings. The accompanying drawings illustrate only typical embodiments of the invention, and since the invention can have other equally effective embodiments, the accompanying drawings should not be construed as limiting the scope of the invention. The drawings are drawn for ease of understanding rather than measurement of the invention. The benefits of the claimed inventive subject matter will be readily understood by those skilled in the art upon reading this description and in conjunction with the accompanying drawings. In the drawings, similar reference numerals are used to indicate similar elements, and:

[0046] Figure 1 This is a schematic diagram of the frame of a wireless charger according to an embodiment of the present invention;

[0047] Figure 2 yes Figure 1 Top plan view of multiple transmitter coils in the image;

[0048] Figure 3 yes Figure 1 Circuit diagram of the controller, driver and multiple transmitter coils in the circuit;

[0049] Figure 4 This is a timing diagram of the first signal transmitted by the transmitter coil in the first communication channel and the second communication channel according to an embodiment of the present invention;

[0050] Figure 5 This is a timing diagram of PWM signals for different communication channels, showing the phase difference, according to an embodiment of the present invention; and

[0051] Figure 6 This is a timing diagram of PWM signals for different communication channels according to an embodiment of the present invention. Detailed Implementation

[0052] Figure 1 This is a schematic diagram of the framework of a wireless charger 102, which includes multiple transmitters to support charging of multiple receiver devices 110. The wireless charger 102 includes a controller 104, multiple drivers 106, and multiple transmitter coils 108 connected to a corresponding one of the drivers 106. The controller 104 controls the multiple drivers 106 to drive the corresponding transmitter coil 108. The controller 104 may include a single controller circuit to manage the coil 108, or it may include multiple controller circuits, each managing a corresponding one of the coils 108. Each transmitter coil 108 and its corresponding driver 106 constitute a transmitter that generates wireless charging power. By including multiple transmitter coils 108 (i.e., multiple transmitters), the wireless charger 102 is capable of simultaneously charging multiple receiver devices 110. Each receiver device 110 includes a receiver coil 112 coupled to one of the transmitter coils 108 to receive power from and communicate with the wireless charger 102. The wireless charger 102 uses, for example, an in-band ASK (Amplitude Shift Keying) communication mechanism to communicate with the receiver device 110.

[0053] In a preferred embodiment, a transmitter driver 106 is coupled to a plurality of transmitter coils 108 to cover a large area, so that a receiver placed in the large area can be matched and charged. Figure 2This is a top plan view of multiple transmitter coils 108 arranged in an array. Transmitter coils A1-A8 and B1-B8 are coupled to two of the drivers 106, with transmitter coils A1-A8 coupled to a first driver for communication via a first channel, and transmitter coils B1-B8 coupled to a second driver for communication via a second channel. Transmitter coils A1-A8 and B1-B8 are arranged adjacent to or overlapping each other, thus providing seamless coverage for the receiver device. For example, transmitter coil A7 overlaps with transmitter coil A4, and transmitter coil A4 overlaps with transmitter coil A3. Furthermore, coils coupled to different drivers 106 overlap, for example in… Figure 2 In the middle, the transmitter coil B8 overlaps with the coil A5, and the coil A5 overlaps with the coil B3.

[0054] When the receiver device is placed on coils A1-A8 and B1-B8, it can couple with multiple coils, and thus with more than one of the drivers 106. Therefore, the receiver device can receive signals from the coils it is coupled with. Signals from multiple communication channels can cause instability in the receiver device's operation, leading to in-band communication interference and abnormal charging behavior.

[0055] Overlapping coils connected to different drivers can interfere with each other due to mutual inductance, because the start time of channel communication is random and has a phase difference. Interference between coils in the corresponding channel can cause rail voltage fluctuations, thus degrading the transmitter. In FOD (Foreign Object Detection) applications that calculate energy loss, coil interference can lead to inaccurate FOD results.

[0056] According to one embodiment of the invention, controller 104 controls driver 106 to drive transmitter coil 108 to perform at least a first-stage communication and a second-stage communication before providing a power signal. In a typical wireless charging protocol such as the Qi protocol, the transmitter coil sends a ping signal in the first stage to determine whether a receiver device is present within its operating range. The ping signal includes a digital ping (DP) signal applied during the ping phase and an analog ping (AP) signal applied during the protection phase, the AP signal consuming less power than the DP signal. After determining the presence of a receiver, the transmitter coil sends a communication signal in the subsequent second stage to configure communication with the detected receiver device. In the Qi protocol, the communication signal sent by the transmitter to the receiver is configured as a data packet, which is generated by FSK modulation of a PWM (power width modulation) signal.

[0057] In one embodiment of the invention, the controller 104 enables only one driver 106 at a time in the first phase. Specifically, in the first phase, the controller 104 allows the transmitter coil 108 coupled to the enabled driver 106 to send a first signal, while simultaneously muting the transmitter coils 108 coupled to the other drivers 106. In response to the first signal from the transmitter coil 108, the receiver device sends a response signal back to the wireless charger 102.

[0058] Upon correctly receiving the response signal, the wireless charger 102 determines to enter the second phase and identifies a transmitter coil to transmit a second signal to communicate with the receiver device that sent the response signal. The identified transmitter coil is one of the transmitter coils 108 coupled to the enabled driver 106. The second signal is used to match the transmitter coil with the receiver device and configure the transmitter to prepare for power transmission. After matching and configuration, the transmitter coil 108 is driven to begin providing a power signal to charge the receiver device. Simultaneously, other transmitter coils 108 that overlap with the operating transmitter coil are disabled. To better avoid interference, other transmitter coils 108 adjacent to the operating transmitter coil are disabled. Here, "adjacent" means overlapping or very close. For example, in... Figure 2 In this configuration, transmitter coil B5 and transmitter coil A3 are adjacent due to overlap, while coil A5 and coil B5 are adjacent due to their very close proximity. Therefore, a disabled transmitter coil and an active transmitter coil may be coupled to the same or different drivers.

[0059] Figure 3 This is a circuit diagram of controller 104, driver 106, and multiple transmitter coils 108 connected to driver 106. The multiple transmitter coils 108 are connected to driver 106 to communicate on the same channel. Driver 106 includes a power supply 302 that provides a supply voltage, typically a direct current (DC) voltage. Driver 106 also includes a bridge circuit comprising four switches S1, S2, S3, and S4, thus implementing the bridge circuit as a full bridge. In other embodiments, the bridge circuit includes only two switches and is implemented as a half bridge. The supply voltage is provided to the bridge circuit. Therefore, the bridge circuit generates signals, such as the aforementioned ping signal, communication signal, and power signal, and provides these signals to the transmitter coils 108. Switches S1-S4 are controlled by controller 104 respectively via control signals.

[0060] The driver 106 also includes switches S5, S6, and S7 connected between the bridge circuit and the transmitter coil 108. Each of switches S5-S7 is connected to a corresponding transmitter coil 108. According to an embodiment of the invention, when transmitting the second signal and the power signal, other transmitter coils that are coupled to the same communication channel as the operating transmitter coil 108, i.e., the same driver 108, are also muted, for example, by opening the corresponding switches of switches S5-S7 connected to the transmitter coil to be muted.

[0061] refer to Figure 4 This is a timing diagram of a first signal transmitted by the transmitter coils of a first communication channel and a second communication channel according to an embodiment of the present invention. D1 shows the first signal transmitted by the transmitter coil of the first channel in the first stage, and D2 shows the first signal transmitted by the transmitter coil of the second channel in the first stage. In a Qi-compliant embodiment of the present invention, pulse 402 represents the AP signal transmitted by the transmitter coil 108 of the first channel in the first stage, and pulse 404 represents the AP signal transmitted by the transmitter coil 108 of the second channel in the first stage.

[0062] Switches S5-S7 connected to the same communication channel are closed alternately to alternately couple the corresponding transmitter coil 108 to the bridge circuit. It can be understood that the transmitter coil 108 transmits a signal when a corresponding switch in S5-S7 is closed. In other words, for communication channels D1 and D2, the switches S5-S7 used to couple the transmitter coil 108 are controlled so that only one switch is closed at a time.

[0063] Pulse 406 represents the DP signal (according to the Qi protocol) transmitted by the transmitter coil 108 of the first channel in the first stage, while pulse 408 represents the DP signal transmitted by the transmitter coil 108 of the second channel in the first stage. Figure 4 As can be seen, only one communication channel (D1 or D2) is allowed to transmit signals at any given time, while the other communication channels are muted. For the wireless charger 102 as a whole, at any given time, only one transmitter coil 108 is transmitting a signal, regardless of the communication channel coupled to that active transmitter coil. The controller 104 thus ensures that only one transmitter coil is active at a time to avoid interference. Figure 3 In one embodiment, the transmitter coil 108 is shown to be connected to or disconnected from the bridge circuit via corresponding switches S5-S7. In other embodiments, the controller 104 may use other methods to enable / disable the driver 106 and / or mute / unmute the transmitter coil 108.

[0064] In other implementations, different communication channels can simultaneously use their respective transmitter coils to transmit signals, thereby improving efficiency. For example, see reference... Figure 2 As shown, when transmitter coil A6 sends the first signal, transmitter coil B8, which is neither overlapping nor adjacent to transmitter coil A6, also sends a signal. Since transmitter coils A6 and B8 do not overlap, the risk of significant mutual interference that could reduce the performance of wireless charging is low.

[0065] If each communication channel is controlled to operate simultaneously (except for one adjacent transmitter coil being activated at a time) to drive its corresponding transmitter coil to transmit signals, the PWM signal used to convert to FSK modulated data and form data packets may inherently have random start times, since communication with the receiver device is initiated at random times. The random start times of the PWM signal exhibit phase differences. On the other hand, in FSK modulation, the phase of the PWM signal will be altered, resulting in phase variations in the PWM signal across different communication channels using their respective PWM signals.

[0066] Figure 5 The phase difference of the PWM signals used for different communication channels is shown. Figure 5 In the PWM signal for the first communication channel D1, the rising edge 502 precedes the rising edge 504 of the PWM signal for the second communication channel D2, thus indicating a phase difference. This phase difference in the PWM signal can cause interference due to the mutual inductance of the transmitter coils.

[0067] In such Figure 6 In one embodiment of the invention shown, the controller 104 synchronizes the PWM signals provided to different communication channels. Specifically, the controller synchronizes the rising edges of the PWM signals to eliminate phase differences. Figure 6 As can be seen, the rising edge 602 of the PWM signal used for the first communication channel D1 and the rising edge 604 of the PWM signal used for the second communication channel D2 occur simultaneously. During operation, when a communication channel is about to send a power signal to its coupled receiver device, the PWM signal used for that communication channel is controlled by the controller 104 to synchronize with the PWM signals used for other communication channels. When a communication channel completes the transmission of an FSK modulated data packet, resulting in a phase difference, the controller 104 synchronizes the PWM signal used for that communication channel, so that the rising edge of that PWM signal occurs at the rising edge of other PWM signals.

[0068] Therefore, in one embodiment of the invention, the PWM signals for the first and second non-silent transmitter coils 108 (typically located in different respective communication channels) other than the muted transmitter coil (immediately adjacent to the operating transmitter coil) are synchronized in such a way that the rising edge of the PWM signal provided for the first non-silent transmitter coil is set to coincide with the rising edge of the PWM signal provided for the second non-silent transmitter coil at the beginning of the transmission of the FSK data packet by the first non-silent transmitter coil and / or when the first non-silent transmitter coil begins to transmit the power signal.

[0069] Implementations of various embodiments have been described herein with reference to specific examples shown. These examples were chosen to assist those skilled in the art in forming a clear understanding of and implementing the embodiments. However, the scope of systems, structures, and devices that can be constructed to include one or more embodiments, and the scope of methods implemented according to one or more embodiments, are not limited to the exemplary examples shown. Rather, those skilled in the art will understand based on this specification that many other configurations, structures, and methods can be implemented according to the various embodiments.

[0070] It should be understood that, with regard to the various positional indications used in the foregoing description of the invention, such as top, bottom, upper, and lower, these indications are given only with reference to the corresponding drawings, and may instead have other positional relationships when the orientation of the device changes during manufacturing or operation. As stated above, those positional relationships are described for clarity only and are not intended to be limiting.

[0071] The foregoing description in this specification refers to specific embodiments and accompanying drawings, but the invention should not be limited thereto; rather, it should be defined by the claims. The described drawings are exemplary and not restrictive. In the drawings, for illustrative purposes, the dimensions of elements may be enlarged and may not be drawn to a specific scale. This specification should also include variations in the tolerances and properties of the elements, operating methods, and other aspects. Various weakened embodiments of the invention should also be included.

[0072] The term "comprising" as used in this description and claims does not exclude other elements or steps. Unless specifically indicated, when using singular forms such as "a" or "an" to refer to a definite or indefinite element, the plural of that element should be included. Therefore, the term "comprising" should not be construed as limited to the items listed thereafter, nor should it be construed as excluding other elements or steps; the scope of the description "the device comprises items A and B" should not be limited to a device that includes only elements A and B. This description indicates that, for the purposes of this description, only elements A and B of the device are relevant. Although coupling generally includes inductive connections, and connection generally means a connection via, for example, wires, the terms "connection," "coupled," and "coupled" used herein all indicate an electrical connection between coupled or connected elements and do not imply the absence of intermediate elements. In describing transistors and their connections, the terms gate, drain, and source are interchangeable with gate, drain, and source, as well as gate terminal, drain terminal, and source terminal.

[0073] For those skilled in the art, various specific variations can be made without departing from the scope of the claims of this invention.

Claims

1. A wireless charger, characterized in that, include: Multiple transmitter coils are arranged adjacent to and / or overlapping each other; A first driver coupled to at least one of a plurality of transmitter coils to drive the at least one coupled transmitter coil to communicate with a receiver device and / or provide power to the receiver device through a first channel; A second driver coupled to at least one of a plurality of transmitter coils to drive the at least one coupled transmitter coil to communicate with the receiver device and / or supply power to the receiver device through a second channel; A controller connected to a first driver and a second driver, wherein the controller is configured to enable only one of the first driver and the second driver at a time during a first phase; the controller is configured to provide PWM signals for synchronizing the transmitter coils coupled to the different drivers.

2. The wireless charger according to claim 1, characterized in that, The controller is configured to allow a transmitter coil coupled to an enabled driver to send a first signal in the first phase, and simultaneously mute transmitter coils coupled to other drivers.

3. The wireless charger according to claim 1, characterized in that, In response to a signal received from the receiver device in the first phase, the controller is configured to identify and drive a transmitter coil coupled to an enabled driver to communicate with and / or supply power to the receiver device in the second phase, and to disable the transmitter coil immediately adjacent to the identified transmitter coil.

4. A wireless charger, characterized in that, include: A plurality of transmitter coils configured to communicate with and transmit energy to a receiver device, wherein the plurality of transmitter coils include at least one first transmitter coil and at least one second transmitter coil overlapping the first transmitter coil; as well as A controller coupled to multiple transmitter coils, wherein the controller is configured to mute a second transmitter coil when the first transmitter coil transmits a signal in response to the first transmitter coil transmitting a signal; the controller is configured to synchronize PWM signals provided for the transmitter coils coupled to different drivers.

5. The wireless charger according to claim 4, characterized in that: Multiple transmitter coils are configured to transmit FSK data packets generated by modulating PWM signals, as well as transmit power signals.

6. The wireless charger according to claim 5, characterized in that: The controller is configured to provide PWM signal synchronization for the non-silent transmitter coils in response to the completion of each FSK data packet transmission from the first transmission in the non-silent transmitter coils other than the silent second transmitter coil. This synchronization is achieved through: The first PWM signal provided for the first non-mute transmitter coil is configured such that the rising edge of the first PWM signal coincides with the rising edge of the PWM signal provided for the other non-mute transmitter coils.

7. The wireless charger according to claim 5, characterized in that: The controller is configured to synchronize a PWM signal provided for a non-mute transmitter coil other than the second transmitter coil that is being muted, the synchronization being achieved through: At the beginning of the first power transmission signal for the non-silent transmitter coil, the first PWM signal for the first non-silent transmitter coil is configured to occur simultaneously with the rising edge of the PWM signal for the other non-silent transmitter coils.

8. A wireless charger, characterized in that, include: Multiple transmitter coils arranged in an array are configured to communicate with and / or supply power to the receiver device; A controller coupled to multiple transmitter coils, wherein the controller is configured to generate FSK data packets from PWM signals and drive multiple transmitter coils to transmit FSK data packets to communicate with a receiver device; The controller is configured to synchronize PWM signals provided for multiple transmitter coils, wherein the synchronization is achieved by: after the FSK data packet is sent, the rising edge of the PWM signal for one of the multiple transmitter coils occurs simultaneously with the rising edge of the PWM signal for the other transmitter coils; the controller is configured to synchronize PWM signals provided for transmitter coils coupled to different drivers.

9. The wireless charger according to claim 8, characterized in that, The controller is further configured to synchronize the PWM signals provided for the multiple transmitter coils, wherein the synchronization is achieved by: before the power signal is transmitted, the rising edge of the PWM signal for one of the multiple transmitter coils occurs simultaneously with the rising edge of the PWM signal for the other transmitter coils.

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