Flux coupling device and magnetic structures therefor
A magnetic flux coupler comprising a magnetically permeable core having a first axis, two coils magnetically associated with the core, each coil defining a pole area located on a first side of the core and the pole areas being separated along the first axis, the coils each having a central region located between the pole areas, an end region opposite to the central region, and a side region between the central region and the end region, wherein an auxiliary pole area is provided beyond the end region of each coil which absorbs leakage flux which would otherwise emanate from the each coil in use in the vicinity of the end region.
1. A device comprising:
a magnetically permeable core with a first side;
two coils disposed on and substantially coplanar with the first side of the magnetically permeable core;
wherein:
the two coils each define a pole area;
the pole areas of the two coils are spaced along a first axis of the magnetically permeable core;
the magnetically permeable core defines two auxiliary pole areas;
the pole areas of the two coils are disposed between the two auxiliary pole areas;
the two auxiliary pole areas are configured to capture leakage flux that escapes the pole areas of the two coils; and
the first side of the magnetically permeable core is narrower in a central region, between the two auxiliary pole areas, than at the ends of the magnetically permeable core next to the two auxiliary pole areas.
2. The device of claim 1 , wherein the two auxiliary pole areas are disposed at opposing ends of the magnetically permeable core immediately adjacent to an edge of the coils.
3. The device of claim 1 , wherein the two auxiliary pole areas comprises transverse sections of the core, and the transverse sections of the core that comprises the auxiliary pole areas extend further in a direction orthogonal to the first axis of the magnetically permeable core than another section of the core that is located between the auxiliary pole areas.
4. The device of claim 1 , wherein the central region of the magnetically permeable core does not extend past the edges of the coils in a direction orthogonal to the first axis.
5. The device of claim 1 , wherein the device comprises a back plate, and the back plate is wider than the central region of the magnetically permeable in a direction orthogonal to the first axis.
6. A magnetic flux coupler comprising:
a magnetically permeable core with a first side having a length direction and a width direction, wherein the core is narrower, in the width direction, in a central region, that is located between opposing longitudinal ends of the core, than at the opposing longitudinal ends of the core; and two coils disposed side by side on and substantially coplanar with the first side of the core, each of the two coils has a nominal centre, and the nominal centers of the two coils are space along the length direction of the core.
7. The magnetic flux coupler of claim 6 , wherein the central region is disposed equidistant between opposing the ends of the length direction.
8. The magnetic flux coupler of claim 6 , wherein the first side of the core is substantially planar.
9. The magnetic flux coupler of claim 6 , wherein the two coils are aligned along a longitudinal axis that extends in the length direction.
10. The magnetic flux coupler of claim 6 , wherein the magnetic flux coupler is symmetric about a transverse axis that extends in the width direction.
11. The magnetic flux coupler of claim 6 , wherein the magnetic flux coupler comprises a shield, the shield is disposed on a second side of the core, the second side of the core is opposite the first side of the core, and the shield is wider than the central region of the core in the width direction.
12. The magnetic flux coupler of claim 6 , wherein the magnetically permeable core extends past the end of the coils in the length direction.
13. The magnetic flux coupler of claim 6 , wherein the magnetically permeable core does not extends past the end of the coils in the width direction.
14. A magnetic flux coupler comprising:
a magnetically permeable core with a first side;
two coils disposed side by side on and substantially coplanar with the first side of the magnetically permeable core;
wherein:
the first side of the magnetically permeable core has an approximate I-shape that is narrower in a central region between the two coils than at the ends of the magnetically permeable core outside the two coils.
15. The magnetic flux coupler of claim 14 , wherein the magnetically permeable core comprises means for capturing leakage flux.
16. The magnetic flux coupler of claim 14 , wherein the magnetically permeable core consists of ferrites.
17. The magnetic flux coupler of claim 14 , wherein the magnetic flux coupler comprises a back plate, and the back plate is wider than the magnetically permeable core in a central region of the approximate I-shape.
18. The magnetic flux coupler of claim 14 , wherein the first side is substantially planar, and the two coils are substantially flat.