Patent ID: 8686820

Claim:
A reactor including a coil and a magnetic core, the coil being formed by winding a wire, the magnetic core including an internal core portion that is inserted through the coil and a couple core portion that is coupled to an end of the internal core portion and that covers an outer periphery of the coil, the core portions forming a closed magnetic path, the reactor comprising: an interposed core portion disposed between the coil and the internal core portion, wherein 0<S 2 /S 1 <0.15 is satisfied, where S 1 is an inner cross-sectional area of the coil and S 2 is a cross-sectional area of the interposed core portion, and wherein B 1 >B 2 and B 1 >B 3 are satisfied, where B 1 is a saturation magnetic flux density of the internal core portion, B 2 is a saturation magnetic flux density of the couple core portion, and B 3 is a saturation magnetic flux density of the interposed core portion.