Wireless battery charger and charge-receiving device
View Patent ↗A wireless charger includes a plurality of conductive coils and electronic circuitry. The coils are disposed around a perimeter and face a generally central area of the perimeter. The coils are connected to and controlled by the electronic circuitry, which includes an electric power receiving circuit and a coil controller. The electric power receiving circuit receives electrical power from an external source and conditions the power for provision to the coil controller. The coil controller controls provision of an oscillating current to select coils within the plurality of coils. A protective enclosure or portable electronic device may have receiving coils disposed at its sides for corresponding to at least two of the conductive coils of the wireless charger.
1. A wireless charging apparatus for charging a battery of a portable electronic device, the wireless charging apparatus comprising;
a plurality of electrically conductive coils, the conductive coils each forming a portion of a perimeter around a receiving area configured to receive the portable electronic device, each conductive coil having a central axis around which the respective conductive coil is formed, the central axis of each conductive coil directed inward from the perimeter, each conductive coil in the plurality of conductive coils including at least one loop of electrically conductive material, the ends of each conductive coil constituting electrical leads; and
electronic circuitry, comprising:
an electric power receiving circuit configured to receive electrical power and to provide at least a portion of the electrical power to a coil controller, and
the coil controller, electrically connected to the electric power receiving circuit and to the electrical leads of the conductive coils, the controller configured to selectively provide a changing electric current to at least one of the conductive coils, the changing electric current inducing a magnetic field around the respective conductive coil selected for receiving the changing electrical current.
2. The wireless charging apparatus according to claim 1 , wherein the coil controller provides the changing electric current simultaneously to at least two of the conductive coils.
3. The wireless charging apparatus according to claim 2 , wherein the coil controller is further configured to provide the changing electric current to each of the at least two conductive coils using a predetermined electric current waveform.
4. The wireless charging apparatus according to claim 3 , wherein the coil controller is configured to provide the predetermined electric current waveform to each of the at least two conductive coils at a different phase of the waveform such that at any given time the current at one of the at least two conductive coils has a different amplitude compared with the current provided to another of the at least two conductive coils.
5. The wireless charging apparatus according to claim 4 , wherein the predetermined electric current waveform is a sine wave.
6. The wireless charging apparatus according to claim 5 , wherein the at least two conductive coils comprises three or more conductive coils, and the coil controller simultaneously provides the predetermined electric current waveform at three different phases of the sine wave, each phase being separated from the other two phases of the three different phases by about 120 degrees and being applied respectively to the three or more conductive coils.
7. The wireless charging apparatus according to claim 2 , further comprising at least one target charging region within the receiving area, wherein the coil controller is configured to provide the changing electric current to each of the at least two conductive coils at respective magnitudes and phases of the electric current that induce complementary magnetic fields, the complementary magnetic fields combining to provide an aggregate oscillating magnetic field at the target charging region.
8. The wireless charging apparatus according to claim 2 , further comprising a detection unit of the electronic circuitry, wherein,
the coil controller is further configured to perform a detection sequence at least once after receiving power from the power receiving circuit, the detection sequence including at least provision of the changing electric current temporarily to each of the conductive coils in a predetermined order, and
the detection unit includes:
a data communication receiver configured to receive, for each conductive coil, a communication from the portable electronic device reporting an amount of power received at the portable electronic device, and
a processing circuit configured to compare each reported amount of power received to a predetermined power amount value and, based on the reported amounts of power received, to determine at least one of the conductive coils to which the coil controller shall supply the changing electrical current.
9. The wireless charging apparatus according to claim 8 , wherein the processing circuit of the detection unit is further configured to determine the at least one of the conductive coils to which the coil controller shall supply the changing electrical current by calculating whether any reported amount of power received is within one of a first predetermined threshold range or a second predetermined threshold range, wherein
the detection unit is further configured to:
if the reported amount of power received is within the first predetermined threshold range, prevent further provision of power to the corresponding conductive coil, and
if the reported amount of power received is within the second predetermined threshold range, initiate transmission of power to the corresponding conductive coil.
10. The wireless charging apparatus according to claim 1 , wherein the plurality of conductive coils includes one or more pairs of the conductive coils, and the coil controller is further configured to provide the changing electrical current to a selectable one pair of the one or more pairs of conductive coils, each pair of conductive coils having a first coil disposed across the perimeter approximately opposite a second coil of the pair of coils, each pair of conductive coils positioned to be respectively proximate a corresponding pair of receiver coils of the portable electronic device when the portable electronic device is disposed in the receiving area in alignment with the selected one of the one or more pair of coils.
11. The wireless charging apparatus according to claim 1 , wherein the conductive coils are disposed edge-adjacent each other, one side portion of each conductive coil being proximate an opposite-side portion of a first adjacent conductive coil and the other side of said each conductive coil being proximate an opposite-side portion of a second adjacent conductive coil.
12. A cupholder of a vehicle, comprising a substantially cylindrical wall having an open top and a closed bottom, the cylindrical wall compassed by the wireless charging apparatus according to claim 1 , the perimeter of the wireless charging apparatus disposed around the cylindrical wall between the open end of the cylindrical wall and the closed bottom of the cylindrical wall.