Wireless Power Systems

Abstract

A power system has a wireless power transmitting device and a wireless power receiving device. Coils in the power transmitting and receiving devices are used to transmit and receive wireless power signals. The coils may include pot core coils, figure eight coils, solenoids, and other coils. A solenoid array may extend under a charging surface in a wireless power transmitting device. Solenoids in the array may be separated from each other by small gaps. Solenoids may have rectangular outlines, hexagonal outlines, or other shapes. Pot core coils may have a magnetic material with a circular groove of a groove of other suitable shapes that contains wire windings. Figure eight coils may have first and second adjacent magnetic cores with respective counterclockwise and clockwise wire windings. Magnets and other alignment structures can be used to help align coils in transmitting and receiving devices.

What is claimed is: 
     
         1 . A portable electronic device comprising:
 wireless power receiving circuitry having:
 a first solenoid portion; 
 a second solenoid portion; 
 a layer of magnetic material joining the first and second solenoid portions; and 
 rectifier circuitry coupled to the first and second solenoid portions. 
   
     
     
         2 . The portable electronic device of  claim 1 , wherein the layer of magnetic material comprises a crack configured to mitigate eddy currents in the portable electronic device. 
     
     
         3 . The portable electronic device of  claim 1 , wherein the layer of magnetic material has a magnetic permeability of at least 500. 
     
     
         4 . The portable electronic device of  claim 1 , wherein the layer of magnetic material has a saturation flux density of at least 1.0 Tesla. 
     
     
         5 . The portable electronic device of  claim 1 , wherein the layer of magnetic material comprises a crystalline foil of magnetic material having a thickness of less than 500 microns. 
     
     
         6 . The portable electronic device of  claim 1 , wherein the layer of magnetic material comprises at least two sublayers. 
     
     
         7 . The portable electronic device of  claim 1 , wherein the first solenoid portion comprises counterclockwise windings along a first magnetic core and wherein the second solenoid portion comprises clockwise windings along a second magnetic core. 
     
     
         8 . The portable electronic device of  claim 7 , wherein the counterclockwise windings and the clockwise windings are part of one continuous wire. 
     
     
         9 . The portable electronic device of  claim 1 , further comprising a magnetic alignment structure around the wireless charging coil. 
     
     
         10 . A wireless power transmitting device comprising:
 wireless power transmitting circuitry having:
 a first post with first wire windings wound helically along the first post; 
 a second post with second wire windings wound helically along the second post; and 
 an inverter circuit configured to produce alternating-current drive signals that are supplied to the first and second wire windings. 
   
     
     
         11 . The wireless power transmitting device of  claim 10 , wherein the wireless power transmitting circuitry comprises a layer of magnetic material joining the first and second posts. 
     
     
         12 . The wireless power transmitting device of  claim 11 , wherein the layer of magnetic material comprises a cracked structure configured to mitigate eddy currents in the wireless power transmitting device. 
     
     
         13 . The wireless power transmitting device of  claim 11 , wherein the layer of magnetic material comprises a crystalline foil of magnetic material having a thickness of less than 500 microns. 
     
     
         14 . The wireless power transmitting device of  claim 11 , wherein the layer of magnetic material comprises at least two sublayers. 
     
     
         15 . The wireless power transmitting device of  claim 11 , wherein the layer of magnetic material has a magnetic permeability of at least 500. 
     
     
         16 . The wireless power transmitting device of  claim 11 , wherein the layer of magnetic material has a saturation flux density of at least 1.0 Tesla. 
     
     
         17 . The wireless power transmitting device of  claim 10 , wherein the first wire windings are wound counterclockwise along the first post and wherein the second wire windings are wound clockwise along the second post. 
     
     
         18 . The wireless power transmitting device of  claim 10 , wherein the first post has a height and a diameter and wherein a ratio of the height to the diameter is less than one. 
     
     
         19 . The wireless power transmitting device of  claim 18 , wherein the height is less than 10 millimeter. 
     
     
         20 . The wireless power transmitting device of  claim 10 , further comprising a magnet surrounding the first and second posts. 
     
     
         21 . An apparatus comprising:
 a housing with a surface;   a layer of magnetic material parallel to the surface; and   at least one solenoid that is coupled to the layer of magnetic material and that has a post and wire windings along the post, wherein the post extends along an axis normal to the surface.   
     
     
         22 . The apparatus of  claim 21 , wherein the layer of magnetic material has a crack. 
     
     
         23 . The apparatus of  claim 21 , further comprising:
 an additional solenoid that is coupled to the layer of magnetic material and that has an additional post and additional wire windings along the additional post, wherein the additional post is parallel to the post.   
     
     
         24 . The apparatus of  claim 21 , further comprising a magnet that runs along a peripheral edge of the at least one solenoid.