Reactor

Abstract

Provided is a reactor having a small size. A reactor 1α includes a coil 2α and a magnetic core 3α in which the coil 2α is disposed. The magnetic core 3α includes an internal core portion 3i that is inserted through the coil 2α and a couple core portion 3o that covers the outer periphery of the coil 2α, and these core portions form a closed magnetic path. The reactor 1α satisfies 1<(B1/B2) and 0.17×(B1/B2)+0.42≦(S1×B1)/(S2×B2)≦0.50×(B1/B2)+0.62, where S1 is the cross-sectional area of the internal core portion, B1 is the saturation magnetic flux density of the internal core portion, S2 is the cross-sectional area of the couple core portion, B2 is the saturation magnetic flux density of the couple core portion, (B1/B2) is the saturation magnetic flux density ratio between the core portions, and (S1×B1)/(S2×B2) is the magnetic flux ratio between the core portions. The cross-sectional area of the internal core portion 3i can be reduced because 1<(B1/B2) is satisfied, and the size of the reactor 1α can be reduced because (S1×B1)/(S2×B2) is adjusted to be in a specific range.

Dependencies are inferred from the claim text.