POWER TRANSMISSION COIL

摘要

A power transmission coil is unsusceptible to a dimensional error between individual coils or a displacement between primary and secondary coils. The power transmission coil includes a first planar coil having an inner diameter (Di) and a second planar coil having an outer diameter (Do) and being disposed opposite to the first planar coil. The quotient of the outer diameter (Do) of the second planar coil and the inner diameter (Di) of the first planar coil is defined as an inner/outer diameter ratio (Do/Di). The rate of change in the coupling coefficient between the first planar coil and the second planar coil is defined as a coupling coefficient change rate (Δk). The inner diameter (Di) of the first planar coil and the outer diameter (Do) of the second planar coil are determined in accordance with the correlation between the inner/outer diameter ratio (Do/Di) and the coupling coefficient change rate (Δk) so that the inner/outer diameter ratio (Do/Di) has a value not more than the value at which the slope of the correlation begins to rise steeply.

主权项

1. A power transmission coil comprising:
a first planar coil having an inner diameter ; and a second planar coil having an outer diameter and being disposed opposite to the first planar coil, wherein a quotient of the outer diameter of the second planar coil and the inner diameter of the first planar coil is defined as an inner/outer diameter ratio; a rate of change in a coupling coefficient between the first planar coil and the second planar coil is defined as a coupling coefficient change rate; and the inner diameter and the outer diameter are determined in accordance with a correlation between the inner/outer diameter ratio and the coupling coefficient change rate so that the inner/outer diameter ratio has a value not more than a value at which a slope of the correlation begins to rise steeply.