Patent ID: 11967830
Assignee: NUCURRENT, INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. A base station for wireless power transfer at an operating frequency selected from a range of about 87 kilohertz (kHz) to about 205 kHz, the base station comprising:
an interface surface;
a control and communications unit;
an inverter circuit configured to receive input power and convert the input power to a power signal;
a coil configured to transmit the power signal to a power receiver, the coil formed of wound Litz wire and including a first layer and a second layer,
each of the first layer and the second layer including a respective number of turns in a range of about 4 turns to about 5 turns,
the coil defining, at least a coil top face,
the coil having an outer diameter length in an outer diameter length range of about 40 mm to about 50 mm,
the coil having an inner diameter length in an inner diameter length range of about 15 mm to about 25 mm; and

an E-Core type ferrite shielding comprising a magnetic core, a magnetic backing, and a magnetic ring having a magnetic ring top face, wherein the magnetic core is centrally positioned on the magnetic backing and the magnetic ring is positioned around an outer edge of the magnetic backing, wherein the magnetic core, the magnetic backing, and the magnetic ring define a cavity in the ferrite shielding, wherein the coil is positioned within the cavity and the cavity is configured with an E-Core configuration such that the ferrite shielding substantially surrounds all but the coil top face, wherein the coil top face is positioned above the magnetic ring top face, and wherein a gap is defined between an outermost turn of the coil and the magnetic ring; and
at least one magnet configured as a ring, wherein the at least one magnet substantially surrounds the outermost turn of the coil, wherein the at least one magnet comprises a magnet top face, wherein the magnet top face is separated from the interface surface by a first separation distance and the magnetic ring top face and the coil top face are separated from the interface surface by at least a second separation distance, wherein the first separation distance is less than the second separation distance, and wherein the at least one magnet configured to attract at least one receiver magnet when the power receiver is proximate to the interface surface of the base station.