REACTOR

PROBLEM TO BE SOLVED: To bring a main leg core and the coil near and arrange them by installing the main leg core disposed through an insulating means and the coil arranged around the main leg core inside a picture-frame-like magnetic circuit formed by using one or more of cores. SOLUTION: A main leg core 3, on which a coil 4 is wound directly, is housed in a C-shaped core 2 while interposing core gap spacers 5 at two upper and lower places, and held down by an I-shaped core I from an upper section and welded and fixed in a core abutting section 6. A reactor is assembled and impregnated with varnish. According to above-mentioned constitution, the main leg core 3 is isolated and insulated completely from other cores 1, 2 and a ground by the core gap spacers 5 functioning as insulating paper in combination. Consequently, a section between the coil 4 and the main leg core 3 need not be insulated, and the coil 4 can be wound directly while using the main leg core 3 as a core. When the core gap spacers 5 having resiliency in the thickness direction are interposed and impregnated with vanish after assembly, magnetic vibrations and magnetic sound can be lowered.