Patent ID: 9208937
Filing Date: 2015-12-08
Classification: H01F

Abstract:
1. A choke comprising: a single-piece core made of a same material, the single-piece core having two boards and a pillar located between the two boards, a winding space being located among the two boards and the pillar, wherein the pillar has a non-circular and non-rectangular cross section along a direction substantially perpendicular to an axial direction of the pillar, the cross section of the pillar has a first axis and a second axis intersecting with each other at a center of the cross section of the pillar and are substantially perpendicular with each other, the first axis is longer than the second axis, and the cross section of the pillar is substantially symmetrical to both of the first axis and the second axis, wherein the first axis starts from a first point on the circumference of the cross section of the pillar and ends at a second point on the circumference of the cross section of the pillar, the second axis starts from a third point on the circumference of the cross section of the pillar and ends at a fourth point on the circumference of the cross section of the pillar, and an inequality is satisfied: wherein X represents a length of the first axis and Y represents a length of the second axis, and the first axis starts from a first point on the circumference of the cross section of the pillar and ends at a second point on the circumference of the cross section of the pillar, the second axis starts from a third point on the circumference of the cross section of the pillar and ends at a fourth point on the circumference of the cross section of the pillar, each of the two boards has a pair of first edges substantially parallel to and longer than the first axis and a pair of second edges substantially parallel to and longer than the second axis, and an inequality is satisfied: wherein M′ represents a shortest length from the first edge to the center of the cross section of the pillar and N′ represents a shortest length from the second edge to the center of the cross section of the pillar, and wherein the center of the cross section of the pillar and a center of each of the two boards are aligned along the axial direction of the pillar.