POWER SOURCE CASE

PROBLEM TO BE SOLVED: To increase a mechanical strength, and to enhance ventilation by making vent holes in a honeycomb on a power source case. SOLUTION: A switching power source 1 has an approximately box-shaped casing (a power source case) 3 made of an alluminum alloy fitted in such a way as to cover the power source body 2 put inside an apparatus body, and a large number of hexagonal vent holes 4 are provided in line, in the upper end side surfaces of the casing 3 corresponding to the vicinities of heat generating members of the power source body. Since the vent holes 4 of the casing 3 have a honeycomb shape, the width of a crosspiece between each vent hole 4 and an adjoining one is equal, and it becomes possible to obtain sufficient opening and to have an excellent ventilation. Besides, the mechanical strength of each vent hole 4 becomes uniform, and the strength does not lower partially, and besides a load caused by a temperature change is not generated either, since the width of a crosspiece between each vent hole 4 and an adjoining one is equal, so the they become stronger as a whole. Moreover, it is difficult for foreign matters such as a screw, etc., to enter from the vent holes 4, since the maximum width of the vent holes 4 is smaller, compared to the opening.