METHOD OF REDUCING NOISE IN MAGNETIC CORE AND MAGNETIC CORE

摘要

This invention relates to a method of reducing noise of a magnetic core which is annular in shape, has a rectangular section, has an outer circumferential surface and an inner circumferential surface, and has a first side surface (upper surface) for connecting one edge of these outer and inner circumferential surfaces and a second side surface (lower surface) for connecting the other edge of the outer and inner circumferential surfaces, comprising partially forming a slit groove entering toward the opposite surface on one of the inner circumferential surface, the first side surface and the second side surface is partially; as well as the following three kinds of low noise type magnetic cores; (I) a magnetic core produced by the aforesaid method; (II) a magnetic core in which two or more magnetic cores are layered to have a positional relation to cause each of the magnetic cores to vibrate at the same phases; and (III) a magnetic core in which an annular magnetic core is stored in an annular storing container having a container main body with a cylindrical outer circumferential wall and a cylindrical inner circumferential wall concentrically arranged therewith having a smaller diameter than that of the outer circumferential wall which are connected through a bottom plate, and having an annular lid covering the opening of a container main body, the inner surface of said storing container is provided with some supporting projections for fixing the magnetic core, and a spacing is formed between the inner surface of the storing container and the magnetic core by the supporting projections.