INDUCTIVE POWER SUPPLY

• US 20140042824A1
• Filed: 10/15/2013
• Published: 02/13/2014
• Est. Priority Date: 08/28/2007
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Fells, Julian Andrew John, Pooley, David Martin
• Granted Patent: US 9,948,358 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

There is disclosed an inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising: determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the field generators is inactive so that fewer than all of the field generators are active simultaneously.

Claims

1-117. -117. (canceled)

118. A primary unit for use in an inductive power transfer system, the system including said primary unit and a secondary device separable from said primary unit, the system of said primary unit and the secondary device being operable to transfer power inductively to the secondary device, said primary unit comprising:

a plurality of field generators each operable to generate an electromagnetic field for transferring power inductively to the secondary device;

a power transfer surface, wherein said plurality of field generators are located at different positions relative to said power transfer surface;

communication circuitry for receiving communication from the secondary device relating to a type of the secondary device;

driver circuitry operable to provide power to said field generators, said driver circuitry including switching circuitry configured to selectively activate at least one first one of said plurality of field generators in a first polarity and at least one second one of said plurality of field generators in a second polarity, wherein said first polarity and said second polarity are opposite to each other; and

wherein, based on said communication received from said secondary device, said driver circuitry selectively drives (1) said at least one first one of said field generators in said first polarity or (2) said at least one first one of said field generators in said first polarity and said at least one second one of said field generators in said second polarity so as to direct electromagnetic flux through the secondary device in a push-pull manner.

119. The primary unit of claim 118 wherein said first polarity is a positive polarity and said second polarity is a negative polarity.

120. The primary unit of claim 118 wherein the type of the secondary device is indicative of whether the secondary device includes a secondary disposed with an axis (1) substantially perpendicular to said power transfer surface or (2) substantially parallel to said power transfer surface.

121. The primary unit of claim 120 wherein, in response to determining the axis of the secondary is disposed substantially perpendicular to said power transfer surface, said driver circuitry drives said first one of said field generators in said first polarity to transfer power inductively to the secondary device.

122. The primary unit of claim 120 wherein, in response to determining the axis of the secondary is disposed substantially parallel to said power transfer surface, said driver circuitry drives said switching circuitry to transfer power inductively to said secondary device in a push-pull manner by activating said first one of said field generators in said first polarity and said second one of said field generators in said second polarity.

123. The primary unit of claim 118 wherein said driver circuitry is operable to provide power to different types of secondary devices.

124. The primary unit of claim 123 wherein the different types of secondary devices include secondary devices from different manufacturers.

125. The primary unit of claim 118 wherein said driver circuitry is operable to transfer power simultaneously to a plurality of secondary devices.

126. The primary unit of claim 125 wherein at least one of the plurality of secondary devices is a different type from another of the plurality of secondary devices.

127. The primary unit of claim 118 further comprising control circuitry configured to control said switching circuitry to selectively activate said at least one first one of said field generators in said first polarity and said at least one second one of said field generators in said second polarity.

128. The primary unit of claim 127 further comprising variable impedance circuitry configured to be adjusted to affect a resonant frequency of the system, wherein said control circuitry is configured to maintain inductive power transfer at or near the resonant frequency by adjusting said variable impedance circuitry.

129. The primary unit of claim 118 further comprising determining circuitry configured to determine a position of the secondary device relative to said power transfer surface, wherein said control circuitry is configured to selectively activate at least one of said plurality of field generators based on said determined position of the secondary device.

130. The primary unit of claim 118 wherein said first one of said field generators and said second one of said field generators are controlled in a predetermined pattern selected in dependence upon the type of the secondary device.

131. An inductive power transfer system comprising:

a primary unit including;

a power transfer surface and a plurality of field generators each operable to generate an electromagnetic field for inductive power transfer;

communication circuitry for receiving communication from at least one secondary device;

switching circuitry configured to selectively activate at least one first one of said plurality of field generators in a first polarity and at least one second one of said plurality of field generators in a second polarity, wherein said first polarity and said second polarity are opposite to each other;

at least one secondary device separable from said primary unit, said at least one secondary device including a power receiver operable to inductively couple with said field generators for inductive power transfer, wherein said at least one secondary device communicates said communication to said primary unit, wherein said communication relates to a respective type of said at least one secondary device; and

wherein, based on said communication received from said at least one secondary device, said primary unit selectively drives (1) said at least one first one of said field generators in said first polarity or (2) said at least one first one of said field generators in said first polarity and said at least one second one of said field generators in said second polarity so as to direct electromagnetic flux through said secondary device in a push-pull manner.

132. The system of claim 131 wherein said first polarity is a positive polarity and said second polarity is a negative polarity.

133. The system of claim 131 wherein said at least one secondary device is a plurality of secondary devices, and wherein said primary unit is operable to transfer power simultaneously to said plurality of secondary devices.

134. The system of claim 133 wherein at least one of said plurality of secondary devices is a different type from another of said plurality of secondary devices.

135. The system of claim 131 wherein said respective type of each of said at least one secondary device is indicative of whether each of said at least one secondary device includes a secondary disposed with an axis (1) substantially perpendicular to said power transfer surface or (2) substantially parallel to said power transfer surface.

136. The system of claim 135 wherein, in response to determining said axis of said secondary is disposed substantially perpendicular to said power transfer surface, said driver circuitry drives said first one of said field generators in said first polarity to transfer power inductively to said secondary device.

137. The system of claim 135 wherein, in response to determining said axis of said secondary is disposed substantially parallel to said power transfer surface, said driver circuitry configures said switching circuitry to transfer power inductively to said secondary device in a push-pull manner by activating said first one of said field generators in said first polarity and said second one of said field generators in said second polarity.

138. A method for use in an inductive power transfer system, the system comprising a primary unit and a secondary device separable from the primary unit, the secondary device being disposable in proximity to a power transfer surface of the primary unit, the primary unit including drive circuitry and a plurality of field generators each operable to generate an electromagnetic field, said method comprising:

receiving communication from the secondary device relating to a type of the secondary device; and

based on the type of secondary device, determining whether to selectively drive (1) at least a first one of the plurality of field generators in one polarity or (2) at least a second one of the plurality of generators in a first polarity and at least a third one of the plurality of generators in a second polarity, wherein the first polarity and the second polarity are opposite.

139. The method of claim 138 wherein the second one of the field generators includes the first one of the field generators.

140. The method of claim 138 further comprising:

determining, based on the type of secondary device, whether the secondary device includes a secondary disposed with an axis (1) substantially perpendicular to the power transfer surface or (2) substantially parallel to the power transfer surface; and

in response to determining the axis of the secondary is disposed substantially parallel to the power transfer surface, transferring power inductively to the secondary device in a push-pull manner by activating the second one of the field generators in the first polarity and the third one of the field generators in the second polarity.

141. The method of claim 140 further comprising:

receiving communication from another secondary device relating to a type of the another secondary device; and

based on the type of another secondary device being indicative of the another secondary device having a secondary disposed with an axis substantially perpendicular to the power transfer surface, transferring power inductively to the another secondary device by activating the first one of the field generators in the one polarity, wherein the secondary device and the another secondary device receive power simultaneously from the primary unit.