US 7,525,283 B2 · Contact-less power transfer

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.

Claims35

Dependent claims

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:

an AC power source;
a field generator electrically coupled to the AC power source, the 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.

A system for transferring power without requiring direct electrical conductive contacts, comprising:

an AC power source;
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 electrically coupled to the AC power source, 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;
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.

2 more elements

Dependencies are inferred from the claim text.

Contact-less power transfer

Life of this patent

Contact-less power transfer

Life of this patent

Abstract

Claims35