WIRELESS POWER TRANSMITTER WITH MULTIPLE PRIMARY COILS AND ADDITIONAL COIL MUTING

Abstract

The present disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on a storage medium, for a wireless power transmitting device that supports charging of one or more wireless power receiving devices. The wireless power transmitting device may include multiple primary coils organized into groups (called zones). Each zone may have a local controller for managing the operation of one primary coil in the zone at a time. A master controller may selectively couple the primary coils to the local controllers. When a first primary coil is coupled to a local controller in a zone, other primary coils in that zone may be disabled. The master controller may manage which primary coils from adjacent zones are coupled to their respective local controllers. Thus, when a first primary coil is energized, adjacent primary coils (near the first primary coil) may be muted or disabled to mitigate undesired interference.

Description

[Technical field]

[0001] The present disclosure relates generally to wireless power, and more specifically to wireless power transmitting devices. [Background technology]

[0002] Conventional wireless power systems have been developed with the primary purpose of charging batteries in wireless powered devices, such as mobile devices, small electronic devices, gadgets, etc. In conventional wireless power systems, the wireless power transmitting device may include a primary coil that generates an electromagnetic field. The electromagnetic field may induce a voltage in the secondary coil of the wireless power receiving device when the secondary coil is placed in close proximity to the primary coil. In this configuration, the electromagnetic field may wirelessly transmit power to the secondary coil. The power may be transmitted using resonant or non-resonant inductive coupling between the primary and secondary coils. The wireless power receiving device may operate using the received power or may store the received energy in a battery for later use. The power transmission capability may be related to how close the primary and secondary coils are placed to each other. Thus, in some conventional wireless power systems, the structure of the wireless power transmitting device may be designed to restrict the positioning of the wireless power receiving device and impose an expected alignment between the primary and secondary coils. Summary of the Invention

[0003] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0004] One innovative aspect of the subject matter described in this disclosure may be implemented in a wireless power transmitting device. In some implementations, the wireless power transmitting device may include a plurality of primary coils organized into at least a first primary coil group and a second primary coil group. The wireless power transmitting device may include at least a first local controller associated with the first primary coil group and a second local controller associated with the second primary coil group. A plurality of switches in the wireless power transmitting device may individually couple the first local controller to one primary coil of the first primary coil group and the second local controller to one primary coil of the second primary coil group. The wireless power transmitting device may include a master controller configured to operate a plurality of switches that control which primary coils of the first primary coil group are coupled to the first local controller and which primary coils of the second primary coil group are coupled to the second local controller.

[0005] In some implementations, the master controller may be configured to determine that a first primary coil of the multiple primary coils is supplying wireless power to a first wireless powered device. The master controller may operate the multiple switches to keep one or more adjacent primary coils in the vicinity of the first primary coil decoupled from their respective local controllers while the first primary coil is supplying wireless power to the first wireless powered device.

[0006] In some implementations, the master controller may be configured to disable the first local controller before changing the state of the multiple switches to control which primary coils of the first primary coil group are coupled to the first local controller. Disabling the first local controller may prevent current from flowing from the first local controller through the multiple switches while the state of the multiple switches is changed. The master controller may enable the first local controller after changing the state of the multiple switches to control which primary coils of the first primary coil group are coupled to the first local controller.

[0007] In some implementations, the plurality of switches includes a first set of switches configured to individually couple the first local controller to one primary coil of the first primary coil group, and a second set of switches configured to individually couple the second local controller to one primary coil of the second primary coil group.

[0008] In some implementations, the wireless power transmitting device may include multiple local controllers including at least a first local controller and a second local controller. At least the first local controller may include a communication unit capable of receiving a communication from the first wireless power receiving device via the first primary coil when the first wireless power receiving device is in proximity to the first primary coil and the first local controller is coupled to the first primary coil. The first local controller may include a control unit configured to manage operation of a driver in response to receiving a communication from the first wireless power receiving device. The first local controller may include a driver configured to generate an electrical output to the first primary coil when the first primary coil is coupled to the first local controller via the multiple switches.

[0009] In some implementations, the first local controller may be configured to determine a status signal to send to the master controller, the status signal based at least in part on a communication from the first wireless powered device, a wireless power transfer status, an electrical output generated in the first primary coil, a fault condition associated with charging the first wireless powered device, or any combination thereof. The first local controller may be configured to send the status signal to the master controller.

[0010] In some implementations, the master controller can be configured to determine that the first primary coil is not providing wireless power to the first wireless power receiving device based at least in part on the status signal. The master controller can operate a plurality of switches to couple the first local controller to one or more other primary coils of the first primary coil group.

[0011] In some implementations, the master controller can be configured to determine that the first primary coil is providing wireless power to the first wireless powered device based at least in part on the status signal. While the status signal indicates that the first primary coil is providing wireless power to the first wireless powered device, the master controller can prevent the multiple switches from disconnecting the first local controller from the first primary coil.

[0012] In some implementations, while the status signal indicates that the first primary coil is supplying wireless power to the first wireless power receiving device, the master controller may be configured to prevent the multiple switches from coupling one or more adjacent primary coils in the vicinity of the first primary coil to their respective local controllers.

[0013] In some implementations, the master controller may be configured to cause the multiple switches to sequentially couple the primary coils of the first primary coil group to the first local controller. The master controller may receive a status signal from the first local controller for each primary coil of the first primary coil group. The status signal may indicate whether the first local controller detects a first wireless power receiving device at the coupled primary coil.

[0014] In some implementations, the master controller may be configured to cause the multiple switches to simultaneously couple a first primary coil of the first primary coil group to the first local controller and a second primary coil of the second primary coil group to the second local controller, where the first primary coil and the second primary coil may not be adjacent.

[0015] In some implementations, the master controller may be configured to operate the multiple switches such that each of the multiple primary coils is coupled to a respective local controller according to a pattern that prevents adjacent primary coils from being coupled simultaneously.

[0016] In some implementations, each primary coil group may include at least two primary coils that can be selectively coupled to a local controller, and each primary coil group may be coupled to its local controller via at least one switch.

[0017] In some implementations, the first primary coil group may include three primary coils selectively coupled to the first local controller via two switches.

[0018] In some implementations, the wireless power transmitting device may include a charging pad on which multiple wireless power receiving devices may be placed, and multiple primary coils may be distributed across multiple layers of the charging pad and arranged in an overlapping pattern.

[0019] In some implementations, at least a subset of the multiple primary coils may be constructed from graphene.

[0020] In some implementations, the first local controller may be configured such that when the first wireless powered device is in proximity to the first primary coil and the first local controller is coupled to the first primary coil, at least a first primary coil of the first primary coil group transmits wireless power to the first wireless powered device in response to communication from the first wireless powered device via the first primary coil. The second local controller may be configured such that when the second wireless powered device is in proximity to the second primary coil and the second local controller is coupled to the second primary coil, at least a second primary coil of the second primary coil group transmits wireless power to the second wireless powered device in response to communication from the second wireless powered device via the second primary coil.

[0021] In some implementations, the first primary coil and the second primary coil may not be adjacent to each other. The first primary coil and the second primary coil may be configured to simultaneously transmit wireless power to the first wireless power receiving device and the second wireless power receiving device, respectively.

[0022] In some implementations, the switches may comprise mechanical or solid-state relays that are controlled switches having normally closed (NC) and normally open (NO) terminals, with switching between states managed by a master controller.

[0023] Another innovative aspect of the subject matter described in this disclosure can be implemented as a method performed by a wireless power transmitting device. In some implementations, the method may include managing connections between a plurality of primary coils and respective local controllers via a plurality of switches. The method may include determining that a first primary coil of the plurality of primary coils is providing wireless power to a first wireless power receiving device. The method may include a master controller operating a plurality of switches such that one or more adjacent primary coils in the vicinity of the first primary coil remain decoupled from the respective local controllers while the first primary coil is providing wireless power to the first wireless power receiving device.

[0024] In some implementations, the multiple primary coils may be organized into at least a first primary coil group that can be individually coupled to a first local controller via a first subset of the multiple switches, and a second primary coil group that can be individually coupled to a second local controller via a second subset of the multiple switches.

[0025] In some implementations, the method may include disabling the first local controller before changing the state of the plurality of switches to control which primary coils of the first primary coil group are coupled to the first local controller. Disabling the first local controller prevents current from flowing from the first local controller through the plurality of switches while the state of the plurality of switches is changed. The method may include enabling the first local controller after changing the state of the plurality of switches to control which primary coils of the first primary coil group are coupled to the first local controller.

[0026] In some implementations, the method may include receiving, by the first local controller, a communication from the first wireless powered device via the first primary coil when the first wireless powered device is in proximity to the first primary coil and the first local controller is coupled to the first primary coil. The method may include determining, by the first local controller, a status signal to transmit to the master controller, the status signal based at least in part on the communication from the first wireless powered device, a wireless power transfer status, an electrical output generated in the first primary coil, a fault condition associated with charging the first wireless powered device, or any combination thereof. The method may include transmitting the status signal from the first local controller to the master controller.

[0027] In some implementations, the method may include determining, based at least in part on the status signal, that the first primary coil is not providing wireless power to the first wireless power receiving device. The method may include operating a plurality of switches to couple the first local controller to one or more other primary coils of the first primary coil group.

[0028] In some implementations, the method may include determining, based at least in part on the status signal, by the master controller that the first primary coil is providing wireless power to the first wireless power receiving device. The method may include preventing, by the master controller, the plurality of switches from decoupling the first local controller from the first primary coil while the status signal indicates that the first primary coil is providing wireless power to the first wireless power receiving device.

[0029] In some implementations, the method may include preventing the multiple switches from coupling one or more adjacent primary coils in the vicinity of the first primary coil to their respective local controllers while the status signal indicates that the first primary coil is supplying wireless power to the first wireless power receiving device.

[0030] In some implementations, the method may include causing a plurality of switches to sequentially couple primary coils of a first group of primary coils to a first local controller. The method may include receiving, for each primary coil of the first group of primary coils, a status signal from the first local controller indicating whether the first local controller detects a first wireless power receiving device at the coupled primary coil.

[0031] In some implementations, the method may include causing a plurality of switches to simultaneously couple a first primary coil of a first primary coil group to a first local controller and a second primary coil of a second primary coil group to a second local controller. The first primary coil and the second primary coil may be non-adjacent.

[0032] In some implementations, the method may include operating a plurality of switches to couple each of a plurality of primary coils to a respective local controller according to a pattern that prevents adjacent primary coils from being simultaneously coupled.

[0033] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions of the following figures may not be drawn to scale. [Brief description of the drawings]

[0034] [Figure 1]1 illustrates an overview of components associated with an exemplary wireless power system according to some implementations. [Figure 2A] 1 illustrates an example wireless power transmitting device having multiple layers of primary coils arranged in an overlapping pattern according to some implementations. [Figure 2B] 2a shows the example wireless power transmitting device of FIG. 2a with multiple wireless power receiving devices being charged simultaneously in accordance with some implementations. [Diagram 3] 1 illustrates example primary coil groups that can be individually coupled to a local controller according to some implementations. [Figure 4] 1 illustrates an example primary coil group and local controllers that may be managed by a master controller according to some implementations. [Diagram 5] 1 illustrates an example arrangement using multiple primary coils according to some implementations. [Figure 6] 13 illustrates an example of muting adjacent primary coils according to some implementations. [Figure 7] 1 illustrates an example pattern of digital pings managed by a master controller according to some implementations. [Figure 8] 1 shows a flowchart illustrating an example process for wireless power transmission according to some implementations. [Figure 9] FIG. 1 shows a block diagram of an exemplary electronic device for use in a wireless power system according to some implementations. Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The following description is directed to a particular implementation for purposes of illustrating the innovative aspects of the present disclosure. However, those skilled in the art will readily recognize that the teachings herein may be applied in many different ways. The described implementations may be implemented in any means, device, system, or method for transmitting or receiving wireless power.

[0036] A conventional wireless power system may include a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may include a primary coil that transmits wireless energy (as a wireless power signal) to a corresponding secondary coil in the wireless power receiving device. The primary coil refers to the wireless energy source (such as induction energy or magnetic resonance energy) of the wireless power transmitting device. The secondary coil of the wireless power receiving device receives the wireless energy. Wireless power transmission is more efficient when the primary coil and secondary coil are placed in close proximity. Conversely, efficiency may decrease (or power transmission may cease) if the primary coil and secondary coil are misaligned. A conventional wireless power transmitting device may include a controller that enables or disables the transmission of wireless energy based on how close the wireless power receiving device is placed relative to the wireless power transmitting device. For example, the transmission of wireless energy may depend on the degree of alignment between the transmitting coil and the receiving coil. In this disclosure, alignment refers to the spatial relationship between the secondary coil of the wireless power receiving device and the primary coil of the wireless power transmitting device.

[0037] To address misalignment concerns and provide greater positioning flexibility, some wireless power transmitting devices may include multiple primary coils. For example, a primary coil may be disposed on the charging surface of the wireless power transmitting device. The primary coils may be configured in an overlapping or non-overlapping arrangement. The arrangement of the primary coils (overlapping or non-overlapping) may be designed to minimize, reduce, or eliminate dead zones. Depending on the orientation and position of the wireless power receiving device on the charging surface, different primary coils may be energized to provide power to corresponding secondary coils of the wireless power receiving device. Thus, the wireless power transmitting device may support positional freedom such that the wireless power receiving device may be charged regardless of the position or orientation of the wireless power receiving device relative to the charging surface. Furthermore, multiple wireless power receiving devices may be charged simultaneously using different primary coils of the wireless power transmitting device. However, when a wireless power transmitting device has multiple primary coils, the unused primary coils may cause undesirable electromagnetic interference (EMI) to nearby primary coils that are providing wireless power to the wireless power receiving device.

[0038] According to the present disclosure, a wireless power transmitting device may have multiple primary coils that can be selectively and individually coupled to a local controller. The local controller may include communication functions, control functions, drivers, or other power signal generating circuitry. In some implementations, the local controller (when connected to one of the primary coils) can implement wireless power transmission according to a standardized wireless power specification, such as the Qi® specification provided by the Wireless Power Consortium. For example, a wireless power transmitting device may include multiple primary coils, and each primary coil can be connected to a local controller to conform to the Qi specification.

[0039] In some implementations, the primary coils may be organized into groups of primary coils that can be managed separately. The groups of primary coils may be referred to as zones in some aspects of the disclosure. Each zone of the wireless power transmitting device may have a separate zone circuit that can be connected to the primary coils in the zone so that each primary coil can be energized independently. For example, the zone circuit may include a local controller, driver, voltage regulator, tank circuit capacitor, etc. that are common to all primary coils associated with the zone. The zone circuits may be connected to the different primary coils using one or more relays or switches. A relay is a type of switch. For example, a relay may be an electromechanical switch or a solid-state switch that can be controlled by a control signal. In some implementations, the relay may have a common terminal, a normally closed (NC) terminal, and a normally open (NO) terminal. When the control signal is not functioning (not energized), an internal switching mechanism of the relay may connect the common terminal and the NC terminal. When the control signal is functioning (energized), an internal switching mechanism may connect the common terminal and the NO terminal. In some implementations, a relay may be a packaged electrical component that includes a switch that is activated or deactivated by a control signal. Thus, the terms relay, controllable switch, or switch may be used interchangeably herein. Although the examples of this disclosure refer to relays for simplicity, it should be understood that other types of switches may be used to connect the zone circuits to the primary coil.

[0040] The connection between the primary coil and the local controller may be made through a relay (or other type of switch). The state of one or more relays may determine which primary coils in a zone are connected to the zone circuit. The zone circuit is common to all primary coils in the zone, but only one primary coil at a time may use the zone circuit. The local controller may use digital ping or other current sensing techniques to determine whether a wireless powered device is located near the primary coil to which the local controller is currently connected. For example, when the local controller receives a communication from a wireless powered device in response to a ping operation, the local controller may determine that the wireless powered device is in proximity to the primary coil currently connected to the local controller. The local controller may cause the primary coil to supply wireless energy to the secondary coil of the wireless powered device. For example, the local controller may operate a driver such that the connected primary coil can transmit wireless power. While the first primary coil in the zone is supplying power to the wireless powered device, the other primary coils remain disconnected based on the state of the relay.

[0041] In some implementations, the master controller can manage the state of the relays in a zone to effectively enable or disable different primary coils. Furthermore, the wireless power transmitting device may include multiple primary coil groups (zones) that can be connected or disconnected to the respective zone circuits. The master controller can manage the relays in multiple zones to prevent adjacent primary coils from operating or transmitting pings while a first primary coil is providing power to the wireless power receiving device. For example, if an adjacent primary coil is energized, the adjacent primary coil may generate undesirable EMI and interrupt the wireless power session of the first primary coil or affect the efficiency of the wireless power session. Thus, in some implementations, the master controller can disable or disconnect (also called "mute") adjacent primary coils to prevent adjacent (near the first primary coil) primary coils from transmitting energy or transmitting pings. Muting adjacent primary coils can be implemented by either preventing the adjacent primary coils from being connected to the local controller via relays or disabling the local controller in the adjacent zone.

[0042] In some implementations, the master controller can disable the zone circuitry before changing the state of the relays in the zone. Power connected through the relays can cause current to flow when the relays switch, which can damage the relays, reduce their lifespan, or both. Thus, in some implementations, the master controller can disable or stop the local controllers in a zone before making changes to the relay connections in that zone. After a short period of time following the change in the relay state, the master controller can re-enable or operate the local controllers. This can extend the lifespan of the relays and improve the reliability of the local controllers in detecting wireless powered devices, since the relays can be changed completely in a zero current environment.

[0043] In some implementations, the master controller may use a pattern when determining which primary coils in various zones to connect to their respective local controllers. For example, when connecting a first primary coil to a first local controller to perform a digital ping or detection procedure, the master controller may not connect adjacent primary coils to their respective local controllers. This pattern may be used to alternate which set of primary coils pings to prevent adjacent or nearby primary coils from pinging at the same time.

[0044] In some implementations, the primary coil is made of a material that improves the reliability and efficiency of the wireless power transmission device. For example, some or all of the primary coil may be made of graphene material, which has higher conductivity and smaller size than traditional materials (such as copper wire). The smaller size allows for thinner layers of overlapping primary coils, which can result in more uniform power transmission of the primary coils in different layers.

[0045] Particular implementations of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages: In some implementations, the described techniques may be used to enable charging of one or more wireless power receiving devices in a variety of positions and orientations. Efficiency of the wireless power transmitting device may be improved by selectively connecting separate primary coils for each zone to a local controller. The electronics in the wireless power transmitting device may use a modular design using common components for groups of primary coils that form different zones. The use of fewer local controllers may reduce the cost and complexity of the wireless power system compared to a system using one local controller for each primary coil. Additionally, the ability to mute adjacent primary coils may improve the efficiency, speed, and reliability of providing power to the wireless power receiving device. For example, muting adjacent primary coils may prevent disturbances that would otherwise affect the charging time for charging the wireless power receiving device.

[0046] FIG. 1 illustrates an overview of components associated with an exemplary wireless power system according to some implementations. The wireless power transmitter 110 may include a power source 180 configured to provide power to various zones within the wireless power transmitter 110. The power source 180 may convert alternating current (AC) to direct current (DC). The wireless power system 100 includes the wireless power transmitter 110 having a plurality of primary coils 120 (shown as primary coils 121, 122, 123, 124, 125, 126). Each of the primary coils 120 may be associated with a different zone circuit. For example, a first group of primary coils 121, 122, and 123 may be associated with a first zone 130. A second group of primary coils 123, 125, and 126 may be associated with a second zone 150. The first zone 130 may include a common zone circuit (including a first local controller 131). In this disclosure, the terms zone circuit and local controller may be used interchangeably. However, it is understood that the zone circuitry may include a local controller as well as other circuit components (including resistors, capacitors, drivers, etc.). Each primary coil may be a wire coil that transmits a wireless power signal (sometimes referred to as wireless energy). Each primary coil may transmit wireless energy using an induction field or a magnetic resonance field (when connected to a local controller via a relay). The zone circuitry may include components (not shown) for preparing the wireless power signal. For example, the zone circuitry may include one or more switches, drivers, capacitors, or other components. An example of a zone circuitry is included in FIG. 3. In some implementations, some or all of the zone circuitry is embodied as an IC that implements features of the present disclosure. Similar to the first zone 130, the second zone 150 may have a second local controller 132.

[0047] One or more relays 141 in the first zone 130 can control which of the primary coils 121, 122, and 123 are connected to the first local controller 131. Similarly, the relay 142 can control which of the primary coils 124, 125, and 126 are connected to the second local controller 132. An example of the relay 141 is included in FIG. 3. The master controller 170 can manage the relays 141, 142 to control which primary coils of each zone 130, 150 are coupled to the local controllers. For example, in FIG. 1, the master controller 170 configures the relay 141 to connect the first primary coil 121 to the first local controller 131. While the first primary coil 121 is connected to the first local controller 131, the other primary coils 122 and 123 in the first zone 130 are disconnected. The master controller 170 connects the second primary coil 125 to the second local controller 132, while the other primary coils 124 and 126 in the second zone 150 are disconnected.

[0048] There may be various ways to implement the master controller 170, including a microcontroller, a dedicated processor, an integrated circuit, an application specific integrated circuit (ASIC), etc. In some implementations, the master controller may be collocated or integrated with one of the local controllers (such as the first local controller 131 or the second local controller 132). For example, an integrated circuit (IC) may implement the functionality of both the master controller and one or more local controllers. Furthermore, in some implementations, a local controller may perform some of the functions described as a master controller (in addition to the functions of a local controller), including polling other local controllers, muting adjacent primary coils, enabling / disabling other local controllers, switching connections between distant primary coils and another local controller, or any combination thereof.

[0049] The first local controller 131 may be configured to detect the presence or proximity of a wireless power receiving device when connected to one of the primary coils 121, 122, 123 in the first zone. For example, the first local controller 131 may cause the connected primary coil to periodically transmit a detection signal and measure a coil current or load change indicative of an object near the primary coil. In some implementations, the local controller may detect pings, wireless communications, load modulation, etc. to determine that a wireless power receiving device is placed on a wireless power transmitting device. In some implementations, the transmitting circuitry may perform detection on an irregular basis or may operate independently to detect the wireless power receiving device. In some implementations, the transmitting circuitry may be configured to perform the detection phase in a pattern such that adjacent primary coils perform the detection phase at deterministic times to reduce adjacent coil interference.

[0050] In the example of FIG. 1, the first wireless power receiver 210 may be detected at the first primary coil 121. The first wireless power receiver 210 has a secondary coil 220. The wireless power receiver may be any type of device capable of receiving wireless power, including a mobile phone, a computer, a laptop, a peripheral, a gadget, a robot, a vehicle, etc. When a wireless power receiver (such as the first wireless power receiver 210) is placed on the wireless power transmitter 110 in the vicinity of the first primary coil 121 and the first local controller 131 is connected to the first primary coil 121 via the relay 141, the first local controller 131 may detect its presence. For example, during the detection phase, the first primary coil 121 may transmit a detection signal (sometimes called a ping). The coil current in the first primary coil 121 may be measured to determine whether it exceeds a threshold indicating that an object is within the electromagnetic field of the first primary coil 121. If an object is detected, the first local controller 131 may wait for a handshake signal (such as an identification signal, a setup signal, etc.) from the first wireless power receiver 210 to determine whether the object is a wireless power receiver or a foreign object. The first wireless power receiver 210 may communicate the handshake signal using a series of load changes (such as load modulation). The load changes may be detectable by a coil voltage or current sensing circuit and may be captured by the first primary controller 131. The first controller 131 may capture the load variations and restore communication from the first wireless power receiver 210. The communication may include information such as charge level, required voltage, received power, receiver power capability, support for wireless charging standards, etc.

[0051] The first wireless power receiving device 210 may include a secondary coil 220, a rectifier 230, a receiving (RX) controller 240, and an optional battery module 250. In some implementations, the battery module 250 may have an integrated charger (not shown). The secondary coil 220 may generate an induced voltage based on the wireless power signal received from the first primary coil 121. A capacitor (not shown) may be in series between the secondary coil 220 and the rectifier 230. The rectifier 230 may rectify the induced voltage and provide the rectified voltage to the battery module 250. The battery module 250 may be within the wireless power receiving device 210 or may be an external device coupled by an electrical interface. The battery module 250 may include a charging stage and protection circuits, such as a temperature detection circuit, an overvoltage protection circuit, and an overcurrent protection circuit. Alternatively, the receiving controller 240 may include a battery charging management module for collecting and processing information regarding the charging state of the battery module 250. In some implementations, the receiving controller 240 may be configured to communicate with the first local controller 131 using load modulation via the secondary coil 220.

[0052] In the example of FIG. 1, since the first wireless power receiving device 210 is detected at the first primary coil 121, the master controller 170 may maintain a connection between the first primary coil 121 and the first local controller 131 via the relay 141. Thus, the other primary coils 122 and 123 in the first zone 130 remain disconnected and do not send pings or cause interference. However, it may be possible that the adjacent primary coil 126 may interfere with the first primary coil 121. Thus, the master controller may prevent the relay 142 from connecting the primary coil 126 to the second local controller 132. In other words, the master controller may be configured to prevent the adjacent primary coils from being connected to the respective local controllers even if the adjacent primary coils are part of another zone.

[0053] In the example of FIG. 1, the second wireless power receiver 260 is near the second primary coil 125. As described above, the second local controller 132 can control the second primary coil 125 separately from other zones. In this manner, the second local controller 132 may cause the second primary coil 125 to transmit wireless power to the second wireless power receiver 260, and the first local controller 131 may cause the first primary coil 121 to transmit wireless power to the first wireless power receiver 210. Furthermore, the first local controller 131 and the second local controller 132 may separately manage parameters related to wireless charging at the respective primary coils. For example, the voltage level, resonant frequency, power level, or other parameters may be different for each of the first primary coil 121 and the second primary coil 125 based on the type of the wireless power receiver or the charge level of the respective batteries.

[0054] In some implementations, the master controller 170 can coordinate the operation of multiple local controllers. For example, the master controller 170 may manage the pattern of detection phases for each zone based on knowledge of the adjacencies of the primary coils.

[0055] Although the example of FIG. 1 shows only six primary coils 121, 122, 123, 124, 125, and 126 organized into two zones 130 and 150, the number of primary coils and zones may vary. For example, the number of primary coils associated with each zone may be less than or greater than three. Additionally, the primary coils may be placed in an overlapping or layered arrangement, with different zones defined between them. In some implementations, the zones may be based on which primary coils are in close proximity to each other, such that if the zones share a common zone circuit, a relay for a zone will effectively disable adjacent primary coils based on the zone relationship. Alternatively, the zones may include primary coils distributed throughout the wireless power transmitting device.

[0056] FIG. 2A illustrates an exemplary wireless power transmitting device having multiple layers of primary coils arranged in an overlapping pattern according to some implementations. The exemplary wireless power transmitting device 200 includes 18 primary coils arranged in two overlapping layers. Again, the number and arrangement of primary coils are shown as an example. Other numbers of primary coils, number of layers, or arrangements may be possible. Additionally, while the primary coils shown in FIG. 2 appear circular to help illustrate the overlapping pattern, other designs may use primary coils that are not circular. For example, the primary coils may be square (or rounded square) similar to those shown in FIGS. 5-7. The design of FIG. 2 can be used to illustrate how a multi-layer system can provide an overlapping arrangement of primary coils in a wireless power transmitting device. In this disclosure, the overlapping arrangement may include designs with overlapping (or matching) side portions.

[0057] 2A, multiple primary coils are distributed between a first layer 152 and a second layer 153. For example, a first primary coil 121 is shown on the first layer 152 along with several other primary coils. A second primary coil 125 is shown on the second layer 153 along with other primary coils.

[0058] 2B illustrates the example wireless power transmitting device of FIG. 2A with multiple wireless power receiving devices being charged simultaneously in accordance with some implementations. FIG. 2B includes the layers 152, 153 described above as a combined view 154 illustrating the coils overlapping. In some implementations, the number of coils and overlaps may be such that the multiple primary coils cover substantially all of the charging surface 155.

[0059] In addition to the wireless power transmitter 200, FIG. 2B shows a first wireless power receiver 210 and a second wireless power receiver 260 placed on the charging surface 155. The first wireless power receiver 210 can latch and receive wireless power from the first primary coil 121 based on its position on the transmitter circuit. Similarly, the second wireless power receiver 260 can latch and receive wireless power from the second primary coil 125. Various optional features may be incorporated into the design of the wireless power transmitter. For example, in some implementations, ferrite material may be used in portions of the wireless power transmitter to maintain a consistent electromagnetic field. Ferrite material may be used to distribute the electromagnetic field evenly.

[0060] FIG. 3 illustrates an example primary coil group that can be individually coupled to a local controller according to some implementations. The example first zone 130 of FIG. 3 is one of many designs that can be used in this disclosure. In the design of FIG. 3, the first zone 130 includes a first group of primary coils 121, 122, and 123, and a zone circuit 310. The zone circuit 310 includes a first local controller 131 that receives DC power using a DC input line 350 that is electrically coupled to a power source 180. The DC power may be a specific voltage (such as 5V or 12V). Alternatively, the local controller may include a power conditioning stage to meet the voltage requirements of the sub-modules in the local controller. The same DC voltage may be electrically coupled to several switches in the zone circuit 310, such as switch 330. The switch 330 may include a semiconductor switch, such as a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or the like. Alternatively, the switch 330 may include a mechanical switch. 3, each switch may be paired with a diode 320. Other components (such as drivers) may be included in the path, but are not shown in the figure.

[0061] The first local controller 131 may also switch devices across the center point of the two legs of the bridge to convert the power source 180 from a DC output to an AC output. The coil voltage VAC is provided to the local controller using link 340. The switches may be used to control the applied voltage to the capacitor and primary coil pair. For example, the first local controller 131 may change the duty ratio of each switch leg, the phase angle of the applied voltage between the switch legs, the frequency of the applied voltage, or a combination thereof. The first local controller 131, switches, drivers, diodes, etc. may be considered as a zone circuit 310. In some implementations, the drivers may be incorporated into the first local controller 131. Furthermore, the first local controller 131 may control the output of the zone circuit 310 using control lines (labeled 1, 2, 3, 4) to each switch. The first local controller 131 and the switches may be electrically coupled to a ground wire 360 ​​to complete the circuit. The capacitor and primary coil form a resonant circuit.

[0062] In some implementations, the zone circuit 310 may include a coil current sensing circuit (not shown). The zone circuit 310 may have the function of detecting a load change of the first primary coil 121. The coil current sensing circuit may be a current sensor connected in series with the first primary coil 121. The first local controller 131 may determine the presence or absence of an object based on the load change measured by the coil current sensing circuit. The local controller may use the sensed current, the sensed voltage VAC 340, or a combination thereof to determine the load change. A communication unit (not shown) may also be present or may be incorporated in the first local controller 131. The communication unit may monitor the load change measured by the coil current sensing circuit and / or the VAC 340 to decode the load modulation data. The communication unit may receive identification information (ID), charging state information, voltage control information, or other information reported by the wireless power receiving device.

[0063] Also shown in FIG. 3 is a relay 141. The relay 141 includes a first relay 311 and a second relay 312. In the example of FIG. 3, two relays can be used to switch the coupling of the three primary coils 121, 122, 123 with the zone circuit 310. The relays 311, 312 may each have two states, normally open (NO) and normally closed (NC). A DC voltage 180 may be used to power the coils (not shown) of the relays 311 and 312 to switch the connection from NC to NO based on a control signal from a master controller (not shown). By changing the state of the relays 311, 312, it is possible to connect the zone circuit 310 to a particular coil of the primary coil. Table 1 shows the states of the relays 311 and 312 that result in different primary coils being connected to the zone circuit 310. Table 1 and the example of FIG. 3 are provided only as examples, and one skilled in the art can implement other combinations, relay circuits, or states. [Table 1]

[0064] Figure 4 illustrates an example primary coil group and local controllers that the master controller can manage according to some implementations. Based on the description of Figure 3, Figure 4 illustrates how the master controller 170 can manage the operation of the first zone 130, which includes the switches 311 and 312 and the first local controller 131. Other portions of the zone circuitry are omitted from Figure 4 for simplicity.

[0065] The master controller 170 may control a first control link 411 to the first relay 311 and a second control line 412 to the second relay 312. The first and second control lines may be on / off signals to switch the state of the relays 311, 312. However, as described above, switching the state of the relays 311 and 312 while current is flowing from the first local controller 131 to one of the primary coils may cause a reduction in the life of the relays. Thus, in some implementations, the master controller 170 may have a control line 431 to the first local controller 131. The control line 431 may be used to enable or disable the first local controller 131. For example, the control line 431 may signal the first local controller 131 to disable the electronics of the local controller (or any other zone circuit controlled by the local controller) so that no current flows through the relays 311 and 312. After disabling the first local controller 131, the master controller 170 may change the state of relays 311 and 312. The master controller 170 may delay for a period of time (e.g., 100 milliseconds) before sending an enable signal to the first local controller 131 via control line 431.

[0066] In some implementations, the master controller 170 may also receive a status signal from the first local controller 131 via the control line 441 to the master controller 170. For example, the status signal may indicate to the wireless powered device whether the first local controller 131 is currently latched (powering). In other examples, the status signal may indicate an operating state, a charging state, or other information available from the first local controller 131. In some implementations, the first local controller may determine the status signal based on a condition such as a communication from the first wireless powered device, a wireless power transmission state, a generated electrical output to the first primary coil, a fault condition associated with charging the first wireless powered device, or any combination thereof. In some implementations, the status signal may be an "on" or "off" signal that indicates whether the first local controller is successfully charging the wireless powered device. In some other implementations, the status signal may include a formatted message (e.g., a tag-length-value (TLV), an information element, or some other format for conveying additional status information). In yet another implementation, the status signal may be transmitted as a digital pulse signal via the control line 441. The master controller may be configured to capture the digital pulse signal to determine the status of the first local controller 131.

[0067] In some implementations, the status signal (or another interface between the first local controller and the master controller) may indicate a fault condition (such as due to overcurrent, foreign object detection, poor quality factors, mismatch, etc.). In the event of a fault condition, the master controller may disable the first local controller 131 using control line 431. For example, if the status signal indicates that the first local controller 131 has a poor connection to the wireless powered device or a foreign object has been detected, the master controller 170 may disable the first local controller 131, change the state of relays 311 and 312, and re-enable the first local controller 131 to see if another primary coil can achieve a better connection to the wireless powered device.

[0068] FIG. 5 illustrates an exemplary arrangement using multiple primary coils according to some implementations. The charging surface in FIG. 5 illustrates an arrangement of thirteen primary coils (numbered 1-13) grouped into five zones. The primary coils in each zone are shaded in a similar grayscale for ease of reference. A first local controller 131 (associated with the first zone) can be coupled to any of primary coils 1, 2, and 6 via relays. A second local controller 132 (associated with the second zone) can be coupled to any of primary coils 3, 4, and 8 via relays. A third local controller 133 (associated with the third zone) can be coupled to any of primary coils 5 and 10 via relays. It should be noted that while the first and second zones may have two relays (as illustrated in FIG. 3), the third zone may only have one relay since there are only two primary coils in the third zone. A fourth local controller 134 (associated with the fourth zone) can be coupled to any of primary coils 7, 11, and 12 via relays. A fifth local controller 135 (associated with the fifth zone) can be coupled to either of the primary coils 9 and 13 via a relay. This arrangement is used to illustrate the example scenarios of Figures 6 and 7. Although the diagrams of Figures 5-7 show the coils as non-overlapping, in some implementations the coils may be partially overlapping.

[0069] Figure 5 illustrates that the master controller 170 can manage multiple zones. In particular, the master controller 170 may have a control line to each of the five zones of Figure 5 (similar to the control lines 411, 412, 431, 441 described in Figure 4). Using the control lines to the relays in each zone, the master controller 170 can control which primary coils throughout the wireless power transmitting apparatus are connected to each of the local controllers 131, 132, 133, 134, and 135.

[0070] FIG. 6 illustrates an example of muting adjacent primary coils according to some implementations. In FIG. 6, primary coil number 6 is charging a wireless powered device (not shown). Due to the configuration of the zones and relays in the first zone, the other primary coils 1 and 2 in the first zone are not connected to the first local controller 131. To prevent interference with primary coil 6, the master controller 170 may mute other adjacent primary coils 5, 7, 10, and 11. For example, the master controller 170 may completely disable the third local controller 133 or control the relays in the third zone to prevent primary coils 5 and 10 from connecting to the third local controller 133. Similarly, the master controller 170 may control the relays in the fourth zone to prevent primary coils 7 and 11 from connecting to the fourth local controller 134. Note that primary coil 12 in the fourth zone can still be used since it is not adjacent to the functioning primary coil 6. Thus, the master controller 170 may control the relay of the fourth zone to connect the primary coil 12 to the fourth local controller 134. The fourth local controller 134 may periodically ping using the primary coil 12 to determine whether a second wireless powered device may be placed on a portion of the charging pad. Similarly, the other primary coils 3, 4, 8, 9, and 13 that are not adjacent to the primary coil 6 may be coupled to their respective local controllers such that they may ping to detect another wireless powered device that may be charged by the respective local controller.

[0071] FIG. 7 illustrates an example pattern of digital pings managed by a master controller according to some implementations. The master controller 170 can control the connection of the primary coils to their respective local controllers to reduce or eliminate the number of adjacent primary coils that transmit pings at the same time. In the example of FIG. 7, there may be four sets of coils (distributed throughout the zone) that transmit pings at different times. The sets of coils are shown with different hatch marks for reference. It should be noted that the example pattern of FIG. 7 is for illustrative purposes only, and the actual pattern may vary with different implementations. Additionally, for simplicity, FIG. 7 illustrates a time when no wireless powered device is currently placed on the charging pad, so all primary coils may be involved in the ping transmission pattern.

[0072] In the exemplary pattern shown in Figure 7, during a first time period, primary coils 1, 3, 10, and 12 may transmit pings to detect the presence of wireless powered devices while the remaining primary coils are disconnected from their respective local controllers. After the first time period, the master controller 170 may 1) disable local controllers 131, 132, 133, 134, and 135, 2) disconnect primary coils 1, 3, 10, and 12, 3) connect local controllers 131, 132, 133, 134, and 135 to a different set of primary coils (primary coils 2, 4, 11, and 13), and 4) re-enable local controllers 131, 132, 133, 134, and 135. Thus, during the first time period, primary coils 1, 3, 10, and 12 transmit pings, and during the second time period, primary coils 2, 4, 11, and 13 transmit pings. This pattern is such that during each time period, adjacent primary coils are not connected to an enabled local controller. Continuing with this pattern, a third time period might include primary coils 6 and 7. A fourth time period might include primary coils 5, 7, and 9.

[0073] FIG. 8 shows a flowchart illustrating an example process for wireless power transmission according to some implementations. Flowchart 800 begins at block 810. At block 810, the wireless power transmitting device can manage connections between multiple primary coils and respective local controllers via multiple relays. For example, the master controller can enable or disable the relays to change the electrical connection between a selected primary coil and a local controller in the same zone. At block 820, the wireless power transmitting device can determine that a first primary coil of the multiple primary coils is supplying wireless power to a first wireless power receiving device. For example, the wireless power transmitting device can receive a status signal from a first local controller connected to the first primary coil. At block 830, the wireless power transmitting device can operate, by the master controller, the multiple relays such that one or more adjacent primary coils in the vicinity of the first primary coil remain decoupled from their respective local controllers while the first primary coil is supplying wireless power to the first wireless power receiving device. For example, the master controller can programmatically determine adjacent primary coils and then send control signals to relays in that zone to ensure that those adjacent primary coils are decoupled from the local controller in that zone.

[0074] FIG. 9 illustrates a block diagram of an exemplary electronic device for use in a wireless power system according to some implementations. In some implementations, the electronic device 900 may be a wireless power transmitter (such as the wireless power transmitter 190). The electronic device 900 may include a processor 902 (possibly including multiple processors, multiple cores, multiple nodes, or multi-threading, etc.). The electronic device 900 may also include a memory 906. The memory 906 may be a system memory or any one or more of the implementations of computer-readable media described herein. The electronic device 900 may also include a bus 990 (PCI, ISA, PCI-Express, HyperTransport®, InfiniBand®, NuBus®, AHB, AXI, etc.).

[0075] The electronic device 900 may include a number of local controllers 962 configured to couple to a number of primary coils 966 via relays 964. A master controller 970 (similar to the master controller 170 described herein) may control the enabling / disabling of the local controllers 962 as well as the state of the relays 964. Additionally, the master controller 970 may receive status signals from the local controllers 962 regarding a current charging state or wireless powered device detection. In some implementations, the local controller 962 may be distributed within the processor 902, the memory 906, and the bus 990. The local controller 962 may perform some or all of the operations described herein, including the operations of the local controllers 131, 132, 133, 134, and 135. The memory 906 may include computer instructions executable by the processor 902 to implement the functionality of the implementations described in FIG. 1-FIG. 7. Any one of these functions may be implemented partially (or entirely) in hardware or in the processor 902. For example, the functionality may be implemented in an application specific integrated circuit, in logic implemented in the processor 902, in a co-processor such as a peripheral or card. Additionally, an implementation may include fewer or additional components not shown in Figure 9. The processor 902, memory 906, and local controller 962 may be coupled to a bus 990. While shown as being coupled to the bus 990, the memory 906 may also be coupled to the processor 902.

[0076] 1-9 and the operations described herein are examples intended to aid in understanding example implementations and should not be used to limit potential implementations or to limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some different operations.

[0077] As used herein, phrases referring to "at least one of" or "one or more of" a list of items refer to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover the possibilities of a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0078] The various example components, logic, logic blocks, modules, circuits, operations and algorithmic processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed herein and their structural equivalents. Interchangeability of hardware, firmware, and software has been generally described in terms of functionality and illustrated in the various example components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

[0079] The hardware and data processing devices used to implement the various example components, logic, logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed using general purpose single-chip or multi-chip processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices (PLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. In some implementations, certain processes, operations, and methods may be performed by circuitry specialized for a given function.

[0080] As mentioned above, in some aspects, implementations of the subject matter described herein can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of methods, operations, processes or algorithms disclosed herein, can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor or computer executable instructions encoded on one or more tangible processor or computer readable storage media for execution by or to control the operation of a data processing device, including the components of the device described herein. By way of example and not limitation, such storage media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, or any other medium that can be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

[0081] Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the scope of the present disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with the present disclosure, the principles, and novel features disclosed herein.

[0082] Moreover, various features that are described herein in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Thus, although features may be described above as functioning in a particular combination and initially claimed as such, one or more features from the claimed combination can, in some cases, be deleted from the combination, and the claimed combination can be directed to a subcombination or a variation of the subcombination.

[0083] Similarly, although the figures show operations in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or in any sequential order, or to perform all of the operations shown, to achieve desirable results. Additionally, the figures may depict one or more exemplary processes in the form of a flow chart or diagram. However, other operations not shown may be incorporated into the exemplary process shown in the schematic. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some situations, multitasking and parallel processing may be advantageous. It should be understood that the separation of various system components in the above-described implementations does not require such separation in all implementations, and that the described program components and systems may generally be integrated together in a single software product or packaged in multiple software products.

Claims

1. A wireless power transmitting device, a plurality of primary coils organized into at least a first primary coil group and a second primary coil group; at least a first local controller associated with the first primary coil group and a second local controller associated with the second primary coil group; a plurality of switches each capable of individually coupling the first local controller to one of the primary coils in the first primary coil group and the second local controller to one of the primary coils in the second primary coil group; a master controller configured to operate the plurality of switches to control which primary coils of the first primary coil group are coupled to the first local controller and which primary coils of the second primary coil group are coupled to the second local controller; and Equipped with The master controller: disabling the first local controller prior to changing a state of a plurality of switches to control which primary coils of the first primary coil group are coupled to the first local controller, and disabling the first local controller prevents current from flowing from the first local controller through the plurality of switches while the states of the plurality of switches are being changed; and further configured to enable the first local controller after changing the states of the plurality of switches to control which primary coils of the first primary coil group are coupled to the first local controller. Wireless power transmission device.

2. The master controller: determining that a first primary coil of the plurality of primary coils is supplying wireless power to a first wireless power receiving device; 2. The wireless power transmitting device of claim 1, further configured to operate the multiple switches such that one or more adjacent primary coils in a vicinity of the first primary coil remain decoupled from their respective local controllers while the first primary coil is supplying the wireless power to the first wireless power receiving device.

3. The plurality of switches include a first set of switches configured to individually couple the first local controller to one primary coil of the first group of primary coils; a second set of switches configured to individually couple the second local controller to one primary coil of the second group of primary coils; The wireless power transmitting device according to claim 1 .

4. The system further includes a plurality of local controllers including at least the first local controller and the second local controller, wherein at least the first local controller: a communication unit capable of receiving communication from the first wireless power receiving device via the first primary coil when the first wireless power receiving device is in proximity to the first primary coil and the first local controller is connected to the first primary coil; a control unit configured to manage an operation of a driver in response to receiving the communication from the first wireless power receiving device; Including, 2. The wireless power transmitter of claim 1, wherein the driver is configured to generate an electrical output to the first primary coil when the first primary coil is coupled to the first local controller via the plurality of switches.

5. The first local controller determining a status signal to send to the master controller, the status signal based at least in part on the communication from the first wireless powered device, a wireless power transfer status, the electrical output generated at the first primary coil, a fault condition associated with charging the first wireless powered device, or any combination thereof; The wireless power transmitting device according to claim 4 , configured to transmit the status signal to the master controller.

6. The master controller: determining, based at least in part on the status signal, that the first primary coil is not providing wireless power to the first wireless power receiver; 6. The wireless power transmitting device of claim 5, further configured to operate the plurality of switches to couple the first local controller to one or more other primary coils of the first primary coil group.

7. The master controller: determining, based at least in part on the status signal, that the first primary coil is providing wireless power to the first wireless power receiver; 6. The wireless power transmitting device of claim 5, further configured to prevent the plurality of switches from decoupling the first local controller from the first primary coil while the status signal indicates that the first primary coil is supplying wireless power to the first wireless power receiving device.

8. The master controller:

8. The wireless power transmitting device of claim 7, further configured to prevent the multiple switches from coupling one or more adjacent primary coils in a vicinity of the first primary coil to a respective local controller while the status signal indicates that the first primary coil is supplying the wireless power to the first wireless power receiving device.

9. The master controller: causing the plurality of switches to sequentially couple primary coils of the first primary coil group to the first local controller; 2. The wireless power transmitting device of claim 1, further configured to receive, for each primary coil in the first primary coil group, a status signal from the first local controller indicating whether the first local controller has detected a first wireless power receiving device at the coupled primary coil.

10. The master controller:

2. The wireless power transmitting device of claim 1, further configured to cause the plurality of switches to simultaneously couple a first primary coil of the first primary coil group to the first local controller and a second primary coil of the second primary coil group to the second local controller, wherein the first primary coil and the second primary coil are not adjacent to each other.

11. The master controller:

13. The wireless power transmitting apparatus of claim 1, further configured to operate the plurality of switches such that each of the plurality of primary coils is coupled to a respective local controller according to a pattern that prevents adjacent primary coils from being simultaneously coupled.

12. 2. The wireless power transmitting device of claim 1, wherein each primary coil group includes at least two primary coils that can be selectively coupled to a local controller, and each primary coil group is coupled to the local controller of the primary coil group via at least one switch.

13. The wireless power transmitting apparatus of claim 12 , wherein the first primary coil group includes three primary coils selectively coupleable to the first local controller via two relays.

14. 13. The wireless power transmitting device of claim 1, further comprising a charging pad on which a plurality of wireless power receiving devices can be placed, the plurality of primary coils being arranged in an overlapping pattern distributed across multiple layers of the charging pad.

15. The wireless power transmitter of claim 14 , wherein at least a subset of the plurality of primary coils is constructed from graphene.

16. when a first wireless power receiving device is in proximity to a first primary coil and the first local controller is coupled to the first primary coil, the first local controller is configured to, in response to communication from the first wireless power receiving device via the first primary coil, cause at least a first primary coil of the first primary coil group to transmit wireless power to the first wireless power receiving device; 2. The wireless power transmitting device of claim 1, wherein when a second wireless power receiving device is in proximity to a second primary coil and the second local controller is coupled to the second primary coil, the second local controller is configured to cause at least a second primary coil of the second primary coil group to transmit wireless power to the second wireless power receiving device in response to communication from the second wireless power receiving device via the second primary coil.

17. 17. The wireless power transmitting device of claim 16, wherein the first primary coil and the second primary coil are not adjacent to each other, and the first primary coil and the second primary coil are configured to simultaneously transmit wireless power to the first wireless power receiving device and the second wireless power receiving device, respectively.

18. The wireless power transmitting device of claim 1 , wherein the plurality of switches comprises relays that are remotely controlled switches managed by the master controller.

19. 1. A method for wireless power transmission by a wireless power transmission device, comprising: managing connections between the plurality of primary coils and respective local controllers via a plurality of switches; determining that a first primary coil of the plurality of primary coils is supplying wireless power to a first wireless power receiving device; operating, by a master controller, states of the plurality of switches such that one or more adjacent primary coils in a vicinity of the first primary coil remain decoupled from their respective local controllers while the first primary coil is supplying the wireless power to the first wireless power receiving device; Including, the plurality of primary coils are organized into at least a first primary coil group that can be individually coupled to a first local controller via a first subset of the plurality of switches, and a second primary coil group that can be individually coupled to a second local controller via a second subset of the plurality of switches; disabling the first local controller prior to changing a state of a plurality of switches to control which primary coils of the first primary coil group are coupled to the first local controller, where disabling the first local controller prevents current from flowing from the first local controller through the plurality of switches while the states of the plurality of switches are being changed; after changing the states of the plurality of switches, enabling the first local controller to control which primary coils of the first primary coil group are coupled to the first local controller; The method further comprises:

20. receiving, by the first local controller, a communication from the first wireless power receiving device via the first primary coil when the first wireless power receiving device is in proximity to the first primary coil and the first local controller is coupled to the first primary coil; determining, by the first local controller, a status signal to send to the master controller, the status signal based at least in part on the communication from the first wireless power receiver, a wireless power transfer status, an electrical output generated in the first primary coil, a fault condition associated with charging the first wireless power receiver, or any combination thereof; transmitting the status signal from the first local controller to the master controller; 20. The method of claim 19, further comprising:

21. determining, based at least in part on the status signal, that the first primary coil is not providing wireless power to the first wireless power receiver; operating the plurality of switches to couple the first local controller to one or more other primary coils of the first primary coil group; 21. The method of claim 20, further comprising:

22. determining, by the master controller, that the first primary coil is providing wireless power to the first wireless power receiver based at least in part on the status signal; preventing, by the master controller, the plurality of switches from decoupling the first local controller from the first primary coil while the status signal indicates that the first primary coil is providing wireless power to the first wireless power receiving device; 21. The method of claim 20, further comprising:

23. 23. The method of claim 22, further comprising: preventing the multiple switches from coupling one or more adjacent primary coils in a vicinity of the first primary coil to a respective local controller while the status signal indicates that the first primary coil is supplying the wireless power to the first wireless powered device.

24. causing the plurality of switches to sequentially couple primary coils of a first primary coil group to a first local controller; receiving, for each primary coil in the first primary coil group, a status signal from the first local controller indicating whether the first local controller has detected the first wireless power receiving device at the associated primary coil; 20. The method of claim 19, further comprising:

25. 20. The method of claim 19, further comprising: causing the plurality of switches to simultaneously couple the first primary coil of a first primary coil group to a first local controller and the second primary coil of a second primary coil group to a second local controller, wherein the first primary coil and the second primary coil are not adjacent to one another.

26. 20. The method of claim 19, further comprising operating the plurality of switches such that each of the plurality of primary coils is coupled to a respective local controller according to a pattern that prevents adjacent primary coils from being simultaneously coupled.

Images