Reactor

A reactor, comprising:

• a main winding substrate forming a main winding, a control winding substrate forming a control winding and a planer core, wherein
• the main winding substrate and the control winding substrate are incorporated in layers into the planer core,
• the planer core has a center leg, a pair of inner legs arranged on both sides of the center leg, and a pair of outer legs arranged outside the inner legs, in which a main winding current of high-frequency current flowing through the main winding generates an AC magnetic flux around each of the pair of inner legs, the magnetic fluxes having a magnetic field in a direction opposite to each other so as to cancel each other out,
• a control current of a direct current flowing through the control winding generates a DC magnetic flux with a uniform magnetic flux density around all the legs of the core, and
• wherein, the main winding substrate consists of a first main winding substrate and a second main winding substrate to hold the control winding substrate from above and below thereof,
• a main winding of the first main winding substrate is formed to surround the center leg and a first inner leg, which is one of the pair of the inner leg, together,
• a main winding of the second main winding substrate is formed to surround the center leg and a second inner leg, which is the other of the pair of the inner legs, together, and
• a control winding of the control winding substrate is formed to surround each of the pair of the first inner leg and the second inner leg individually.