Contact-less power transfer
4 Assignments
0 Petitions
Accused Products
Abstract
There is disclosed a system and method for transferring power without requiring direct electrical conductive contacts. There is provided a primary unit having a power supply and a substantially laminar charging surface having at least one conductor that generates an electromagnetic field when a current flows therethrough and having an charging area defined within a perimeter of the surface, the at least one conductor being arranged such that electromagnetic field lines generated by the at least one conductor are substantially parallel to the plane of the surface or at least subtend an angle of 45° or less to the surface within the charging area: and at least one secondary device including at least one conductor that may be wound about a core. Because the electromagnetic field is spread over the charging area and is generally parallel or near-parallel thereto, coupling with flat secondary devices such as mobile telephones and the like is significantly improved in various orientations thereof.
885 Citations
152 Claims
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1-76. -76. (canceled)
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77. A system for transferring power without requiring direct electrical conductive contacts, the system comprising:
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a power transfer surface shaped and arranged such that a secondary device can be placed in a working disposition on or in proximity to the surface to receive power when the system is in use;
a primary unit having a field generator, distributed in two dimensions across a generating area at or substantially parallel to said power transfer surface, and operable to generate an electromagnetic field over a power transfer area of said surface within which area the secondary device can couple flux effectively when in its said working disposition and which area is not substantially smaller than said generating area; and
a secondary device separable from the primary unit and including at least one electrical conductor with which the electromagnetic field generated by the field generator couples and induces a current to flow in the conductor when the secondary device is in said working disposition;
wherein the field generator is configured such that, when a predetermined current is supplied thereto and the primary unit is effectively in electromagnetic isolation, field lines of the electromagnetic field generated by the field generator are distributed in two dimensions over said power transfer area and, when considering the angles subtended by the field lines to a measurement plane that is parallel to the power transfer surface and is at the same distance therefrom as the secondary device when that device is in its said working disposition, an average of said angles over any quarter length part of said power transfer area, measured parallel to the direction of the field lines, is 45°
or less. - View Dependent Claims (78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90)
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91. A primary unit for use in a power transfer system having a power transfer surface shaped and arranged such that a secondary device, separable from the primary unit, can be placed in a working disposition on or in proximity to the surface to receive power from the primary unit without requiring direct electrical conductive contacts between the primary unit and the secondary device, which primary unit comprises:
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a field generator, distributed in two dimensions across a generating area at or substantially parallel to said power transfer surface, and operable to generate an electromagnetic field over a power transfer area of said surface within which area the secondary device can couple flux effectively when in its said working disposition and which area is not substantially smaller than said generating area;
wherein the field generator is configured such that, when a predetermined current is supplied thereto and the primary unit is effectively in electromagnetic isolation, field lines of the electromagnetic field generated by the field generator are distributed in two dimensions over said power transfer area and, when considering the angles subtended by the field lines to a measurement plane that is parallel to the power transfer surface and is at the same distance therefrom as the secondary device when that device is in its said working disposition, an average of said angles over any quarter length part of the power transfer area, measured parallel to the direction of the field lines, is 45°
or less. - View Dependent Claims (92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104)
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105. A method of transferring power from a primary unit to a secondary device, separable from the primary unit, without requiring direct electrical conductive contacts between the primary unit and the secondary device, the method comprising:
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generating an electromagnetic field over a power transfer area of a power transfer surface using a field generator distributed in two dimensions across a generating area at or substantially parallel to said power transfer surface, the power transfer surface being shaped and arranged such that the secondary device can be placed in a working disposition on or in proximity to the power transfer surface to receive power from the primary unit, and the power transfer area being an area of said surface within which the secondary device can couple flux effectively when in its said working disposition and being not substantially smaller than said generating area, and said field being such that, when the primary unit is effectively in electromagnetic isolation, field lines of the field are distributed in two dimensions over said power transfer area and, when considering the angles subtended by the field lines to a measurement plane that is parallel to the power transfer surface and is at the same distance therefrom as the secondary device when that device is in its said working disposition, an average of said angles over any quarter length part of the power transfer area, measured parallel to the direction of the field lines, is 45°
or less; and
placing such a secondary device in said working disposition so that the electromagnetic field couples with at least one electrical conductor of said secondary device and induces a current to flow therein.
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106. A primary unit for use in a power transfer system having a power transfer surface shaped and arranged such that a secondary device, separable from the primary unit, can be placed in a working disposition on or in proximity to a power transfer area of the surface to receive power from the primary unit without requiring direct electrical conductive contacts between the primary unit and the secondary device, the primary unit comprising:
a field generator having a plurality of substantially coplanar conductive elements arranged at or beneath the power transfer surface in a generating area, which elements extend generally in parallel with one another across said generating area, and which generate an electromagnetic field distributed across the power transfer area, wherein the conductive elements have a mutual spacing sufficiently small that the secondary device overlaps two or more of the conductive elements when in its said working disposition, and the respective instantaneous currents which flow simultaneously through all the conductive elements in said generating area have the same general direction. - View Dependent Claims (107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124)
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125. A system for transferring power without requiring direct electrical conductive contacts, comprising:
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a power transfer surface shaped and arranged such that a secondary device can be placed in a working disposition on or in proximity to a power transfer area of the surface to receive power;
a primary unit comprising a field generator having a plurality of substantially coplanar conductive elements arranged at or beneath the power transfer surface in a generating area, which elements extend generally in parallel with one another across said generating area, and which generate an electromagnetic field distributed across the power transfer area, wherein the conductive elements have a mutual spacing sufficiently small that the secondary device overlaps two or more of the conductive elements when in its said working disposition, and the respective instantaneous currents which flow simultaneously through all the conductive elements in said generating area have the same general direction; and
a secondary device separable from the primary unit and including at least one conductor with which the electromagnetic field generated by the field generator couples and induces a current to flow in the conductor when the secondary device is in its said working disposition. - View Dependent Claims (126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136)
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137. A system for transferring power without requiring direct electrical conductive contacts, the system comprising:
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a power transfer surface shaped and arranged such that a secondary device can be placed in a working disposition on or in proximity to a power transfer area of the surface to receive power when the system is in use the power transfer area being large enough that the secondary device is placeable in more than one lateral position within the area;
a primary unit having a field generator having, at or beneath the power transfer area, a plurality of substantially coplanar conductive elements for generating an electromagnetic field distributed over the power transfer area; and
a secondary device separable from the primary unit and having a magnetic unit which is arranged to couple inductively with the electromagnetic field generated by the primary unit when the field lines of the field pass through the magnetic unit in a predetermined coupling direction, said magnetic unit being adapted to couple primarily with field lines of the field that are generally parallel to the power transfer surface;
wherein the conductive elements extend in different directions within the power transfer area such that, in different parts of the power transfer area, each of length at least equal to a length of said magnetic unit in said coupling direction, the inductive elements extend generally in parallel with one another in a width direction of the part concerned and the respective instantaneous currents which flow simultaneously through all the conductive elements in the part concerned are unidirectional so that, within substantially the whole area of the part, resolved components of the field lines parallel to the power transfer surface extend generally in parallel with one another in the length direction of the part. - View Dependent Claims (138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150)
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151. A primary unit for use in a power transfer system having a power transfer surface shaped and arranged such that a secondary device, separable from the primary unit, can be placed in a working disposition on or in proximity to the surface to receive power from the primary unit without requiring direct electrical conductive contacts between the primary unit and the secondary device, which primary unit comprises:
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field generating means, distributed in two dimensions across a generating area at or substantially parallel to said power transfer surface, for generating an electromagnetic field over a power transfer area of said surface within which area the secondary device can couple flux effectively when in its said working disposition and which area is not substantially smaller than said generating area;
wherein the field generating means is configured such that, when a predetermined current is supplied thereto and the primary unit is effectively in electromagnetic isolation, field lines of the electromagnetic field generated by the field generating means are distributed in two dimensions over said power transfer area and, when considering the angles subtended by the field lines to a measurement plane that is parallel to the power transfer surface and is at the same distance therefrom as the secondary device when that device is in its said working disposition, an average of said angles over any quarter length part of the power transfer area, measured parallel to the direction of the field lines, is 45°
or less.
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152. A primary unit for use in a power transfer system having a power transfer surface shaped and arranged such that a secondary device, separable from the primary unit, can be placed in a working disposition on or in proximity to a power transfer area of the surface to receive power from the primary unit without requiring direct electrical conductive contacts between the primary unit and the secondary device, the primary unit comprising:
field generating means having a plurality of substantially coplanar conductive elements arranged at or beneath the power transfer surface in a generating area, which elements extend generally in parallel with one another across said generating area, for generating an electromagnetic field distributed across the power transfer area, wherein the conductive elements have a mutual spacing sufficiently small that the secondary device overlaps two or more of the conductive elements when in its said working disposition, and the respective instantaneous currents which flow simultaneously through all the conductive elements in said generating area have the same general direction.
Specification