Patent ID: 11929202
Assignee: MOJO MOBILITY, INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B  Y | IPC B  H

Claim 52:
53. A mobile device that receives power inductively, the mobile device comprising:
a receiver to inductively receive power for the mobile device; wherein:
the receiver includes:
a solenoid, wherein the solenoid includes:
a magnetic core having a relative magnetic permeability exceeding 1 and having first and second ends; and
wire wrapped around a section of the magnetic core forming a wire wound section around the magnetic core, with the magnetic core extending beyond the wire wound section; and

a receiver electronic circuit, wherein the receiver electronic circuit includes a resonant capacitor and a rectifier; and

when the receiver is positioned proximate to a charger surface of an inductive charger, the receiver receives power from the charger, and the charger includes:
a printed circuit board having a charger coil, wherein the charger surface is a substantially planar surface of the charger coil;
a substantially planar magnetic layer under the charger coil opposite the charger surface;
a charger drive circuit, wherein the charger drive circuit includes a resonant capacitor and a field effect transistor (FET) switch to apply an alternating voltage to the charger coil; and
means for positioning the receiver in a power transfer position, proximate to the charger, to inductively transfer power to the receiver of the mobile device;

wherein:
the charger drive circuit is configured to drive the charger coil at one or more operating frequencies to inductively transfer power from the charger to the receiver when the receiver is positioned in the power transfer position, wherein when the receiver is positioned in the power transfer position, a tuned circuit, which includes the charger coil and the resonant capacitor of the charger drive circuit and the solenoid and the resonant capacitor of the receiver electronic circuit, has a resonant frequency that allows the charger to transfer the power to the receiver at the one or more operating frequencies;
the charger does not include magnetic material between the charger coil and the solenoid when the receiver is positioned in the power transfer position;
the charger coil includes a conductor patterned to include multiple, substantially concentric turns for generating a magnetic flux through a first end of the solenoid when the receiver is placed in the power transfer position, wherein an outermost of the concentric turns defines a perimeter of a charger coil area;
the multiple concentric turns, when driven by the charger drive circuit, generate a magnetic field that is substantially perpendicular to the charger surface at the charger surface at a geometric center of the charger coil area;
the charger coil area is larger than an area of the first end and larger than an area of the second end of the magnetic core of the solenoid;
the magnetic layer of the charger extends beyond the charger coil area; and
when the receiver is in the power transfer position, the first end of the magnetic core is located proximate to the charger coil area above the charger surface to receive magnetic flux from the charger coil area and guide the magnetic flux in a closed magnetic loop from the charger coil area through the solenoid and return through the charger magnetic layer to the charger coil area to form the closed magnetic loop.