ELECTRONIC BALLAST APPARATUS

PROBLEM TO BE SOLVED: To provide a low-cost electronic ballast apparatus not requiring many types of cylindrical metal exterior covers 30. SOLUTION: An electronic ballast 10 for lighting a discharge lamp is provided in the electronic ballast apparatus. The electronic ballast 10 is provided with a bottom cover 12 and a top cover 14 which are both tub shapes. The bottom cover 12 and the top cover 14 are merged and forms a cylindrical shape. The bottom cover 12 is longer than the top cover 14. Attaching holes 16 are formed on both ends of the bottom cover 12. The cylindrical metal exterior cover 30 is provided. The electronic ballast 10 is inserted and positioned inside the exterior cover 30. A pair of metal end lids 32 to seal both ends of the exterior cover 30 are provided. A waterproofing packing 34 existing between each end lid 32 and the exterior cover 30 is provided. An abutting part 36 abutting a shoulder part of the bottom cover 12 is formed on the waterproofing packing 34. The bottom cover 12 is brought into a pressurized contact with the exterior cover 30 by being pressed to the abutting part 36 in a process of attaching the end lid 32 to the exterior cover 30. COPYRIGHT: (C)2006,JPO&NCIPI