1. A power-supply device comprising:
a circuit board; and
a casing which includes a casing portion having an opening, and a cover portion disposed to cover the opening of the casing
wherein the casing portion has a through hole formed at a position corresponding to a connector terminal connected to the
circuit board, and
at least one rib is provided to a region having a size greater than or equal to an outside diameter of a connector of an external
connector line connected to the connector terminal in the casing portion.