Abstract: The invention comprises a main distribution arrangement for a telephone exchange, including a rack (1); several subscriber-related connectors whose positions are affixed to the rack, coordinated to one or more connection terminals (2a); and several external connectors that belong to telephone exchange-related line circuits, also affixed to the rack and coordinated to one or more connection terminals (3a). Said connection terminals are situated close to one another, and are arranged, with required main distribution conductors (23), to connect selected subscriber-related connectors with selected telephone exchange-related external connectors. A predetermined number of telephone exchange-related line circuits are coordinated to a block (10). Each block (10) can be inserted into and removed from the rack along parallel bars (11, 12).

Abstract: An arrangement is provided that may be used for cooling electronic equipment, where the electronic equipment is housed in a rack arrangement with an arrangement for transferring the heat energy produced by the equipment to one or more rack-related cooling units each of which is designed to transfer heat energy by means of convection to the ambient air about the rack and the equipment. At least one of the cooling units contains vertically-oriented cooling flanges, positioned next to one another, and a fan unit that is designed to be able to provide, on demand, the cooling unit and the cooling flanges with a stream of forced air, thereby increasing heat emission from the cooling flanges to the ambient air. The fan unit is located at the side of a rack unit, and positioned beside, or part way inside, the cooling unit.

Abstract: The invention relates to a cross-connection arrangement for a telephone exchange. The arrangement includes a frame (1), a number of frame-mounted subscriber-associated connection pins (24, 24') in one or more terminal units (2a), and a number of frame-mounted telephone-exchange-related line-circuit-associated connection pins in one or more terminal units (3a'). The terminal units are disposed close together and have necessary jumpers (23) for connecting selected subscriber connection pins with selected telephone-exchange connection pins via contact devices (33, 34) connected to the ends of said conductors. The contact devices (33, 34) and the conductors (31, 32) extend into an open space (26) defined by a bar (20) to which the subscriber terminal units (2a) are related.

Abstract: The invention relates to a matrix switching device (1) having a plurality of contact devices positioned in selected crosspoints between rows and columns, with each contact device including at least one movable contact element (2a). The device further includes a plurality of row-related, reciprocatingly movable first rods (3), a plurality of column-related reciprocatingly movable second rods (4, 4'), a plurality of electrically insulating balls (2h, 2g) of which each is allotted a selected crosspoint and is movable in response to movement of one or both of the rods (3, 4). Two mutually adjacent balls (2g, 2h) are provided at each selected crosspoint. A first ball (2g) has a larger diameter than a second ball (2h), and the first ball is so dimensioned that when moving it causes the movable contact element (2a) to move in one direction, and the second ball (2h) is so dimensioned as to have no effect on the movable contact irrespective of said movement.

Abstract: The invention relates to a matrix switching device (1) having a plurality of contact devices positioned in selected crosspoints between rows and columns, with each contact device including at least one movable contact element (2a). The device further includes a plurality of row-related, reciprocatingly movable first rods (3), a plurality of column-related reciprocatingly movable second rods (4, 4'), a plurality of electrically insulating balls (2h, 2g) of which each is allotted a selected crosspoint and is movable in response to movement of one or both of the rods (3, 4). A thin module unit is obtained since the movable contact element is comprised of a contact spring mounted on a printed circuit board.

Abstract: A method for the supervision of clock signals in a digital data system in which data is clocked progressively by clock signals through a number of registers includes supervisory flip flops associated with each register with a clock supervision bit progressively clocked through the flip flops which together from a supervision chain. The absence of one or more of the clock signals prevents the clock supervision bit from propagating to the end of the chain. By monitoring said clock supervision bit after propagation through the supervision chain it can be determined whether clock signals are supplied correctly to all registers.