Sparse-routed magnetic coils for wireless power charging system
A sparse routing coil structure for a magnetic coil in a wireless charging system is disclosed. The sparse routing coil structure may include a magnetic coil routed by turns of a wire and a turn spacing S between adjacent turns of the wire. The turn spacing S may be a space between adjacent turns of the wire, and a turn width is denoted as W. A ratio of W/S may be not larger than 10.
1. A wireless charging system comprising a transmitter and a receiver,
wherein the transmitter includes:
a power amplifier accepting an power input; and
a power transmitter connected to the power amplifier, and comprising a transmitter coil,
the receiver includes:
a power receiver comprising a receiver coil,
wherein the transmitter coil and the receiver coil are magnetically coupled with each other, and each having a sparse routing coil structure, comprising:
a magnetic coil having a first end and a second end, and routed by a plurality of turns of a wire at a routing plane, wherein each of the plurality of turns of the wire has a diameter different with a diameter of any of the rest of the plurality of turns,
wherein a ratio of W/S is not larger than 10, S is a turn spacing representing an edge-to-edge distance between adjacent turns of the wire, W is a turn width representing a width of the wire,
and wherein the first end and the second end are elicited from one of the plurality of turns with a smallest diameter and one of the plurality of turns with a largest diameter, respectively, and extending along a same direction in the routing plane.
2. The wireless charging system in claim 1 , wherein each magnetic coil includes a solid wire, the turn width W is a diameter of the wire.
3. The wireless charging system in claim 1 , wherein each magnetic coil has a substantially circular shape.
4. The wireless charging system in claim 1 , wherein each magnetic coil has an outer diameter of 48-52 mm.
5. The wireless charging system in claim 1 , wherein each magnetic coil has an inner diameter of 23-27 mm.
6. The wireless charging system in claim 1 , wherein each magnetic coil has 9-11 turns.
7. The wireless charging system in claim 1 , wherein the turn spacing S is 0.55-0.75 mm.
8. The wireless charging system in claim 1 , wherein the wire is made of copper, and has a turn width W of 0.5-0.7 mm.
9. The wireless charging system in claim 1 , wherein each magnetic coil includes a Litz wire including stranded wires and coating materials, the turn width W is an outer diameter of an outer shape of the stranded wires and coating materials.
10. The wireless charging system of claim 1 , wherein each magnetic coil includes a printed circuit board or a flexible printed circuit board, the ratio of W/S is not larger than 5.
11. The wireless charging system of claim 1 , wherein each magnetic coil includes a printed circuit board or a flexible printed circuit board which comprises a trace clearance, the turn spacing S is a sum of the trace clearance and an added space in addition to the trace clearance.
12. The wireless charging system in claim 11 , wherein the turn width W is a width of a trace.
13. The wireless charging system of claim 1 , wherein the magnetic coil has one or more layers of coils.