Wirelessly rechargeable battery and power transmitter

Abstract

A wirelessly rechargeable battery is provided having coils oriented off major battery axes to facilitate good coupling with power transmitter magnetic fields. A magnetic core may house charging electronics for a compact form factor. A wireless power transmitter that produces fields to maximize coupling with receiver coils.

1 .- 38 . (canceled) 
     
     
         39 . A wireless power transmitter including:
 a. a plurality of power transmission coils arranged in a planar array; and   b. a driving circuit for driving the coils such that at least a first coil is driven so as to produce an alternating magnetic field of opposite polarity to that produced by a second coil.   
     
     
         40 . A wireless power transmitter as claimed in  claim 39  wherein the first and second coils are positioned in the planar array adjacent one another. 
     
     
         41 . A wireless power transmitter as claimed in  claim 39  wherein a plurality of first coils is driven so as to produce an alternating magnetic field of opposite polarity to that produced by the second coil. 
     
     
         42 . A wireless power transmitter as claimed in  claim 41  wherein the first coils and second coil are positioned in the planar array adjacent to one another. 
     
     
         43 . A wireless power transmitter as claimed in  claim 39  wherein the wireless power transmitter detects wirelessly rechargeable batteries coupled to the planar array. 
     
     
         44 . A wireless power transmitter as claimed in  claim 43  wherein the power supplied by the driving circuit to the coils is reduced when no batteries are present. 
     
     
         45 . A wireless power transmitter as claimed in  claim 43  wherein the power supplied by the driving circuit to the coils is reduced when disrupting metallic bodies are detected. 
     
     
         46 . A wireless power transmitter as claimed in  claim 43  wherein the wireless power transmitter includes a communication circuit for communication with batteries. 
     
     
         47 . A wireless power transmitter as claimed in  claim 46  wherein the communication circuit detects communications via variations in power demand of batteries. 
     
     
         48 . A wireless power transmitter as claimed in  claim 47  wherein the variations are in the form of pulses.