Abstract: First and second tapered holes are provided at facing positions of the first and second circuit boards. The elastic spacer including first and second spacers is attached between them to couple the two in parallel and thereby facilitate attachment of the two to a back panel. The first spacer is provided at one end part with a tapered part which fits with the first tapered hole and the second spacer is provided at one end part with a tapered part which fits with the second tapered hole. A spring is inserted between the two spacers. The first spacer is fit in the tapered hole and fastened by a screw to the first circuit board. The second circuit board is fastened by a screw to the first spacer in a state fitting the second tapered hole over the second spacer with the second circuit board approaching the first circuit board.

Abstract: An apparatus has a plurality of printed board units each including a printed board, a frame to have the printed board arranged therein, a first rail to be arranged at a first lower end of an inner wall of the frame having the printed board located thereon in a lower opening of the frame, and a second rail to be arranged at a second lower end opposed to the first lower end in the opening; a housing including a rail holding unit to movably hold the first rail of a first printed board unit and the second rail of a second printed board unit adjacent to the first printed board unit among the plurality of printed board units; and a cooling fan to be arranged on an upper side or underside of the housing to send air into the frame.

Abstract: A second printed wiring board is opposed to a surface of the first printed wiring board. A support member supports the first and second printed wiring boards. A first connector is mounted on the first printed wiring board. A second connector is mounted on the second printed wiring board. A wiring connects the first printed wiring board to the second printed wiring board. The first and second connectors are separately mounted on the first and second printed wiring boards, respectively. The sizes of the first and second printed wiring boards can be reduced as compared with the case where connectors are arranged in a row on a single printed wiring board, for example. This results in a reduction in the size of the printed circuit board unit. A large number of the printed circuit board units can be coupled to the back panel.

Abstract: An apparatus has a plurality of printed board units each including a printed board, a frame to have the printed board arranged therein, a first rail to be arranged at a first lower end of an inner wall of the frame having the printed board located thereon in a lower opening of the frame, and a second rail to be arranged at a second lower end opposed to the first lower end in the opening; a housing including a rail holding unit to movably hold the first rail of a first printed board unit and the second rail of a second printed board unit adjacent to the first printed board unit among the plurality of printed board units; and a cooling fan to be arranged on an upper side or underside of the housing to send air into the frame.

Abstract: A power supply apparatus includes a power supply circuit and a module that has a replaceable or detachable structure. The power supply apparatus copes with an equipment that uses a single-phase A.C. power by connecting a single-phase power reception module to the power supply apparatus, and copes with an equipment that uses a three-phase A.C. power by connecting a three-phase power reception module to the power supply apparatus.

Abstract: A second printed wiring board is opposed to a surface of the first printed wiring board. A support member supports the first and second printed wiring boards. A first connector is mounted on the first printed wiring board. A second connector is mounted on the second printed wiring board. A wiring connects the first printed wiring board to the second printed wiring board. The first and second connectors are separately mounted on the first and second printed wiring boards, respectively. The sizes of the first and second printed wiring boards can be reduced as compared with the case where connectors are arranged in a row on a single printed wiring board, for example. This results in a reduction in the size of the printed circuit board unit. A large number of the printed circuit board units can be coupled to the back panel.