Abstract:
Wireless power transmittal apparatus and systems are disclosed in which transmitter and receiver inductors, or coils, are coupled in configurations for wirelessly transferring power and/or data among them. In preferred implementations, a plurality of non-coplanar primary side coils are provided in power transmittal apparatus for transmitting power, or power and data.

Description:
PRIORITY ENTITLEMENT 
       [0001]    This application is entitled to priority based on Provisional Patent Application Ser. No. 61/468,685 filed on Mar. 29, 2011, which is incorporated herein for all purposes by this reference. This application and the Provisional Patent Application have at least one common inventor. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to coupled inductor systems. More particularly, the invention relates to coupled inductor systems for use in wireless power and data transfer applications. In preferred embodiments employed in wireless power applications, the invention relates to the more efficient utilization of energy resources. 
       BACKGROUND OF THE INVENTION 
       [0003]    Inductive coupling is an effect used to transfer electrical energy from one circuit to an adjacent circuit through inductive coils. A variable current on a primary coil is used to create a varying magnetic field, and thus a voltage, in a secondary coil. Wireless charging systems employing inductive coupling are useful for transferring energy from one apparatus to another. Such systems are used for supplying power, charging batteries, and in some cases also for transferring data. Challenges inherent in such systems include providing efficiency in transferring power. Inefficient systems generate excess heat and are limited in their maximum power transfer capability. Charging of common electronic apparatus, such as 3D glasses, toys, remote controls and other portable rechargeable electronics traditionally has required wired plugs to be inserted into the apparatus as a source of power for the charging of batteries. Techniques using inductive resonance can transmit power, but are limited in their utility, in part by the geometry of charging systems known in the art. Known inductive resonance systems are designed to transmit signals from point-to-point in a generally co-planar orientation, or between members of parallel-plane coil pairs. Moreover, wireless charging systems typically are capable of charging only one device at a time. 
         [0004]    Due to these and other problems and potential problems, improved coupled inductor systems for wireless power transmittal would be useful and advantageous contributions to the arts. In particular, apparatus capable of charging two or more devices simultaneously, and in different orientations, e.g., not necessarily co-planar point-to-point, would be a useful and advantageous contribution to the art. 
       SUMMARY OF THE INVENTION 
       [0005]    In carrying out the principles of the present invention, in accordance with preferred embodiments, the invention provides advances in the arts with novel apparatus directed to the transfer of power and/or data using inductive couplings among coils. In preferred embodiments, systems include capabilities for power and/or data transfer. Preferably, the coupled coils of systems of the invention are not permanently physically interconnected. 
         [0006]    According to aspects of the invention, examples of preferred embodiments include multiple coil wireless power transmittal systems including at least two primary side coils for transmitting a signal. In systems also equipped with a secondary side, the coils are not physically affixed to one another. When positioned in proximity, the primary and secondary side coils are electromagnetically, but not physically coupled such that one or more signals may be passed between the coils. 
         [0007]    According to aspects of the invention, in an example of presently preferred embodiments, apparatus for wireless power transmittal includes a primary side with non-coplanar primary coils. Driver circuitry is connected with the primary coils in a configuration suitable for transmitting a signal from the driver through the primary side coils. 
         [0008]    According to aspects of the invention, some of the preferred embodiments additionally include a secondary side having a secondary side coil adapted for receiving a power signal from the primary side coils. 
         [0009]    According to aspects of the invention, preferred embodiments of the invention include apparatus for wireless power transmittal wherein the primary side having data transmission, receiving, or transceiver functionality. 
         [0010]    According to additional aspects of the invention, preferred embodiments include moveable primary side coils. 
         [0011]    According to aspects of the invention, preferred embodiments of a system for wireless power transmittal include a primary side having a plurality of non-coplanar primary coils and driver circuitry for driving the primary coils. This arrangement is provided with the capability of transmitting a signal through the primary side coils for receipt by a secondary side coil included on a secondary side adapted for receiving a power signal. 
         [0012]    According to aspects of the invention, preferred embodiments of coupled inductor apparatus and systems for wireless power transfer also include data transmission functionality. 
         [0013]    The invention has advantages including but not limited to one or more of, improved coupled inductor system power transfer, improved data transmission functionality, improved convenience in wireless charging systems, and reduced costs. These and other potential advantageous, features, and benefits of the present invention can be understood by one skilled in the arts upon careful consideration of the detailed description of representative embodiments of the invention in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention will be more clearly understood from consideration of the following detailed description and drawings in which: 
           [0015]      FIG. 1  is a simplified perspective view depicting an example of a preferred embodiment of wireless power transmittal apparatus according to the invention in which non-coplanar primary coils are deployed on a plurality of surfaces; 
           [0016]      FIG. 2  is a simplified perspective view depicting an example of a preferred embodiment of wireless power transmittal apparatus according to the invention in which non-coplanar primary coils are deployed on a plurality of surfaces, and a secondary coil is positioned in proximity to the primary side apparatus; 
           [0017]      FIG. 3  is a simplified perspective view of wireless power transmittal apparatus illustrating an example of a preferred embodiment of the invention in which primary coils are configured in series; 
           [0018]      FIG. 4  is a simplified perspective view depicting an example of a preferred embodiment of wireless power transmittal apparatus according to the invention having interlaced primary coils; 
           [0019]      FIG. 5  is a simplified diagram illustrating a three-plane inductive resonance system in an example of a preferred embodiment of the invention; 
           [0020]      FIG. 6  is a simplified diagram of a portion of wireless power transmittal apparatus illustrating an example of a primary coil present in two planes in a preferred embodiment of the invention; and 
           [0021]      FIG. 7  is a simplified schematic diagram of wireless power transmittal apparatus illustrating an example of the use of preferred embodiments of the invention in combination within the context of a broader system. 
       
    
    
       [0022]    References in the detailed description correspond to like references in the various drawings unless otherwise noted. Descriptive and directional terms used in the written description such as right, left, back, top, bottom, upper, side, et cetera, refer to the drawings themselves as laid out on the paper and not to physical limitations of the invention unless specifically noted. The drawings are not to scale, and some features of embodiments shown and discussed are simplified or amplified for illustrating principles and features as well as advantages of the invention. 
       DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0023]    The present patent application is related to U.S. patent application Ser. No. 13/430,338 which shares at least one common inventor with the present application and has a common assignee. Said related application is hereby incorporated herein for all purposes by this reference. 
         [0024]    In the presence of an active primary coil, if a load is connected to the secondary coil of a coupled inductor system, an electric current flows in the secondary coil, and electrical energy is then transferred from the primary coil to the secondary coil, and ultimately to a load connected to the secondary side. An example of a preferred embodiment of apparatus for wireless power transmittal according to the invention is shown in  FIG. 1 . The apparatus  100  includes a number of primary coils  102  for transmitting power to a secondary side receiver (not shown in  FIG. 1 ). A driver circuit  104  is coupled to the coils  102 . Preferably, the driver circuit  104  is capable of adjustment in terms of frequency and amplitude in order to adjust transmission parameters. Suitable startup circuitry is provided in the driver circuit  104  in order to enable the apparatus  100  to achieve appropriate bias levels prior to driving the primary side coils  102 . This preferably provides the capability for a smooth startup that mitigates or eliminates wasted energy and radiated emissions. Adjustable resistors may also be provided in order to regulate the amplitude of the transmitted signal for output at the primary side coils  102 . The primary side coils  102  are preferably arranged so that they do not share the same plane. It has been found that providing primary side coils in non-coplanar configuration tends to provide favorable signal transmission coverage to a space in proximity to the primary side coils. Thus, it may be anticipated that placement of one or receivers having secondary coil(s) in this proximity facilitates reception of the transmitted signal(s) in all or most secondary coil orientations. As can be seen in the example of  FIG. 1 , the primary coils  102  are non-coplanar, arranged around the periphery of a container  106 , in this case box-shaped. In presently preferred embodiments, primary coils (e.g.,  102 ), are arranged in two to six different planes, although other non-coplanar arrangements may be used. It should be understood that a container (e.g.,  106 ) may be implemented in various three-dimensional forms as alternatives to the generally rectangular box  106  shown without departure from the principles of the invention. For example, containers of tubular, cylindrical, envelope, pouch, bag, or pocket shape may also be used. 
         [0025]    In general, in accordance with the invention, one or more inductive resonance receivers having secondary coils may be placed in close proximity with the apparatus for wireless power transmittal as exemplified in and described with respect to  FIG. 1 . Now referring primarily to  FIG. 2 , another preferred embodiment of apparatus of the invention  200  is shown. It has been determined that a suitable secondary side coil  202  may be used to receive signals transmitted by the primary side coil(s)  102 . In preferred embodiments of the invention, apparatus for wireless power transmittal  100  may be used for recharging power storage elements  204 , including but not limited to batteries, capacitors, and super-capacitors. Preferably, electronic devices and systems, herein generally referred to as “receivers”  206  having secondary coils  202  are included in association with an electronic systems having additional functionality, such as cell phones, toys, 3D glasses, cameras, remote controls, and the like. Preferably, during periods when the receiver  206  is not being used, it is placed in proximity with the primary coils  102  of the power transmittal apparatus  100  for recharging with little or no care as to the orientation of the receiver  206  in relation to the primary coils  102 . The secondary side receiver  206  includes a secondary side coil  202  suitable to be inductively coupled with the primary side coil  102  for receiving the signal output of the primary side apparatus  100 . Preferably, the secondary side receiver  206  also includes circuitry  208  suitable for such functions as managing received signals, generating feedback signals such as power levels, load levels, and secondary side frequency, for use in making adjustments to the output of the primary side  100 . The configuration of the power transmittal apparatus  100 , providing non-coplanar coils  102 , as shown on the periphery of the container  106  in this example, permits the transmission of one or more signals from one or more of the primary coils  102  to the secondary coil(s)  202  of the proximal receiver  206  without requiring precise, coplanar, or parallel alignment of the respective coils  102 ,  202 . In this example, the box-like container  106  includes primary coils  102  on each of its three axes, X, Y, and Z, at various angles ⊖, to provide multi-directional transmission of power signals to the secondary coil  202  almost without regard to the precise locations and/or orientations (Θ) of the receiver(s)  206 . Although signals may be transmitted from primary coils to parallel or coplanar secondary coils, such alignment is not required. It is contemplated that apparatus may be implemented in accordance with the invention in configurations which preclude coplanar or parallel primary and secondary coils, for example with cylindrical primary side containers. 
         [0026]    Variations are possible within the scope of the invention and they cannot and need not all be shown. Examples of alternative embodiments are shown in  FIG. 3  and  FIG. 4 . In the illustration of  FIG. 3 , apparatus  300  for wireless power transmittal has non-coplanar primary coils  302  connected in series. Operating the primary coils  302  in series transmits signals having various orientations for reception by suitable secondary coil(s). In  FIG. 4 , apparatus  400  is shown in which the primary coils  402  are arranged in an interlaced configuration. In this configuration, signals transmitted from the primary coils may be concentrated in specific areas in their proximity. Preferably, transmittals through the primary coils may be controlled by dynamic coil selection. Not shown in these partial views, it should be understood that the outside of the container  106  may be covered with electromagnetic shielding (not shown) to provide a Faraday Cage. This effectively eliminates or attenuates the emission of electromagnetic radiation from the container, and thereby reduces the potential of interference with other electronics or the environment. The container including the apparatus of the invention may be of a fixed nature, drawing power from a fixed source, or may be portable, in which case an energy storage element may be used to power to apparatus. In further variations, the apparatus of the invention may also be implemented in transmitter/receiver combinations, further described herein. 
         [0027]    In another example of an alternative embodiment of the invention depicted in  FIG. 5 , it can be seen that the apparatus  500  for wireless power transmittal may be implemented in forms that dispense with the container depicted elsewhere herein. The XY, YZ, and XZ planes in the apparatus  500  each contain one or more primary coils (not shown). It is contemplated that devices including suitable secondary coils, e.g.  510 , may be placed in the proximity of the apparatus  500  in order to receive a signal therefrom. For example, the apparatus  500  may be embedded within a table lamp, and remote control devices containing secondary coils  510  may be placed near the lamp for recharging. Such a system may also include an energy storage element, which would be useful for power outages or to move the unit to a location that is not near a power outlet. 
         [0028]    As shown in  FIG. 6 , it is not essential for the primary coils  602  in the invented wireless power transmittal apparatus  600  to lie entirely in one plane. The coil(s), e.g.,  602 , may lie in tow or more planes. Thus, a signal transmitted from the coil shown  602 , transmits in more than one direction for receipt by a suitable device  610  in proximity. Primary coils need not be on orthogonal planes, and may be oriented at various angles Θ. Preferably primary coil parameters can be changed based on anticipated and/or real-time operational conditions. For example, inductance values, number of windings, the selection of frequencies, and the propagation of different waveguides, may be changed without departure from the invention. Combinations of different planes may also be used to target specific transmission directions. This yields many possible different coil and plane combinations, which allows for flexibility in adjusting the transmission path/direction, either along the X, Y, and Z axes, or adjusting the angle Θ primary coil(s). 
         [0029]    It is within the scope of the invention to equip the wireless power transmittal apparatus with circuitry for performing both transmitting and receiving functions. As shown in  FIG. 7 , a system  700  may be deployed in which wireless power apparatus  702  is implemented as a transceiver. Using multiple transceiver apparatuses  702 , the apparatus  702  may be inductively coupled in various combinations such as daisy chain, star, mesh, or other network configurations. These transceivers  702  may also include energy storage devices such as batteries in order to provide system flexibility, removing the limitation of requiring placement near power outlets. These transceiver units  702  can also be used as power repeaters to extend the distance for power transmission, or to provide a transmission path around obstacles. Communication between each of the receivers  702  is preferably maintained to improve power transfer and communicate system  700  parametric data such as power received, battery life remaining, charge rate, number of charge cycles, orientation, fault/warning conditions, and other operating parameters. The transceiver apparatus  702  may also be used in combination with transmit-only  704 , and receive-only  706  units. A system  700  as shown in  FIG. 7  may be used, for example, in the context of a home entertainment setup with charging apparatus  702 , storage boxes  705 , repeaters  704 , and remote powered speaker receivers  706 . 
         [0030]    Without departure from the scope of the invention, the wireless power transmittal apparatus may be equipped with a communication protocol for providing communication functionality between each primary and secondary coil. Communication functions may include, for example, monitoring the amount of power received by a receiver. This allows the primary side transmitter to vary different parameters to help optimize the power transfer to the receiver. An example is to increase or decrease output power in selected primary coils to determine the best coil or coil combination to use to efficiently transfer the signal. Another example is to mount each primary coil on a movable assembly such as a motorized gimbal, to allow movement of the coil to various orientation angles to optimize power transmission. In a feedback loop, the primary side apparatus may alter the coil angle, and when the receiver reports its power received, this loop may then be repeated to find the most preferred coil position for present-time operating conditions. Another example of communication functions includes device identification, such as through a serial number. Providing each unit in a system ( 700 , in  FIG. 7 ) with a unique serial number, either programmable or assigned by the manufacturer, established their unique identities. If multiple receivers are placed in the proximity of the charging unit, e.g.,  702 , then the transmitter can query each receiver one at a time until all are in communication. Then, the transmitter can determine all or some of the following: which receiver should control the amount of power transmitted; which receiver should determine the appropriate primary coil(s) to use; which receiver should determine the orientation of the primary coil(s); and which receiver should determine other operating parameters of the transmitter. Preferably, receiver status parametrics can also be communicated, such as power received, battery life remaining, charge rate, number of charge cycles, orientation, fault/warning conditions, and other operating parameters. Communication may be embedded in the power transfer signal transmissions. One example is that power transfer and be turned on/off creating an on/off pulse stream of power that is interpreted into a data stream. Communication and other aspects of the invention are further described in the applications incorporated by reference. 
         [0031]    While the making and using of various exemplary embodiments of the invention are discussed herein, it should be appreciated that the present invention provides inventive concepts which can be embodied in a wide variety of specific contexts. It should be understood that the invention may be practiced with coupled inductor systems having communications and power transfer functionality, such as for example, battery chargers, AC/DC converters, power supplies, and associated apparatus. For purposes of clarity, detailed descriptions of functions, components, and systems familiar to those skilled in the applicable arts are not included. The methods and apparatus of the invention provide one or more advantages including but not limited to, data transfer capabilities, managed power transfer capabilities, and enhanced energy utilization and conservation attributes. While the invention has been described with reference to certain illustrative embodiments, those described herein are not intended to be construed in a limiting sense. For example, variations or combinations of steps or materials in the embodiments shown and described may be used in particular cases without departure from the invention. Different coil shapes, coil materials, and additional magnetic materials, e.g. ferrite, may be used in the implementation of the apparatus of the invention. Various modifications and combinations of the illustrative embodiments as well as other advantages and embodiments of the invention will be apparent to persons skilled in the arts upon reference to the drawings, description, and claims.