JPS5642319A - Cyrindrical ballast stabilizer - Google Patents

Abstract

PURPOSE:To obtain a smaller sectional shape of an illuminator by a method wherein a stick-type inner core, on the circumferential section of which a coil is wound in an insulated state of condition, is installed in a pipe-type outer core and the size of the inner core and the outer core is properly selected. CONSTITUTION:A winding 11 is wound on the stick-type inner core 9 through an intermediate of a bobbin 10 or an insulator and the core 9 is inserted in the pipe- type core 12 aligning an axial center. And the outside diameter (a) of the core 12 is to be less than the outside diameter of the lamp to be used. Hence, when this cylindrical ballast stabilizer is assembled in an illuminator, the form of cross section of the illuminator does not become larger. Also, the sectional area of magnetic path of the core 12 of pi(a<2>-b<2>)/4 is to be equal to the magnetic path sectional area of pid<2>/4 of the core 9 or more. In addition, the diameter (d) of the core 9 is to be above 50% of the inside diameter (b). Hence, the wound number of winding 11 is reduced giving an economical advantage, a voltage regulation is improved and a sufficient winding space can be provided.