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and three width modules. The construction is in principle the same as describedabove: the only significant difference is that these units can containseveral cards clamped together, which thus also allows a greater number ofexternal connexions. The fronts of these units can vary in appearance dependingon what they contain: thus a unit might contain power transistors andrequire cooling fins, or it might include electron tubes which must be accessiblefrom the outside. However, as in the smaller units, the front alwayscarries a nameplate on the right-hand side. For 3-module units the cases areat present not manufactured by cold flow moulding for production reasons,but are fabricated from aluminium sheet and light alloy extruded section.An example of a unit of this type is shown in fig. 5.Fig. 7 X 2528Alarm unit occupying one width modulePower Supply and Alarm EquipmentUnits with this type of construction are shown in figs. 6 and 7. Theseunits are built up on a low chassis, beneath which there is practically onlyroom for bolt-heads and nuts. A front panel, given the same enamel finishas the bay itself, is fixed to the chassis by brackets and is provided with ahandle for removal of the unit. Plug-in connexions to the bay are providedby means of connectors of type RPV 100-108 or 120. The unit wiring is ofconventional form.The width module of 93 mm (3.66") for this form of construction has beenobtained by dividing the total available bay width by 6. There are chassis etc.for 1, 2, 3 and 4 width modules. Four bay height modules are occupied bythis construction.Bay Frame and FixturesBay Frame and CablingThe bay frame consists of two C-shaped upright members formed fromsheet metal, held together by cross-members at the top and bottom: steelsheet has been chosen because of the large number of tapped holes in theupright members. The frame is enamelled and numbered in height modulesfrom the bottom upwards along the edge bent inwards from the front (seefig. 9). The frame is provided with a number of tapped holes for each heightmodule for fixing unit supports etc.Fig. 8 X 8233Shelf construction for units primarily withprinted wiringThe figure also shows how the bay cabling is run.120
Fig. 9 X 7790Exploded drawing of the shelf construction offig. 8Inside the uprights of the bay frame run an earth busbar and vertical cableforms; the latter are secured at intervals to a number of perforated strips, inany of whose perforations a plastic-clad aluminium strap clip can be fixedand fastened round the cable form. Branch cables run from these verticalcable forms to the various unit sockets.Shelf Mounting for UnitsThis arrangement is shown in figs. 8-10.As previously mentioned, units are placed in the bay with the card contactstrips vertical. The contacts fit into corresponding sockets, type RNV 212:these sockets are bolted as required, each with a guide plate, onto a ladderliketransverse frame, which in turn is fastened to the bay.The functions of the guide plate are to lift the rear of the unit so thatthe plug and socket mate correctly and also to provide shielding betweenadjacent sockets (fig. 10) by its backwardly-directed tongue.Fig. 10x 8240Bay seen from the rearOne of the covers has been removed to display thelayout and soldering of the cabling and to show screeningbetween adjacent sockets.121
Page 3 and 4: ERICSSON REVIEWVol. XXXVII No. 4 19
Page 5 and 6: application stage. To be sure, the
Page 7 and 8: varistors and the British Post Offi
Page 9 and 10: Gas pressure is being increasingly
Page 11 and 12: In the field of radio link and wave
Page 13 and 14: Fig. 4 X 7798Integrated time-multip
Page 15 and 16: e calculated at a reasonable cost.
Page 17 and 18: cally attractive. This means that m
Page 19 and 20: units were either connected by plug
Page 21: wiring, their soldering tags or lea
Page 25 and 26: Fig. 13Central part of the bayX7789
Page 27 and 28: Fig. 17Fig. 18Fig. 17 X 8236Coaxial
Page 29 and 30: The Centralograph Used for Producti
Page 31 and 32: Main GroupeiCODES FOR CENTRALOGRAPH
Page 33 and 34: in that machine's "output" column.
Page 35 and 36: NEWS fromAll Quarters of the "World
Page 37 and 38: LP"The Sultan of Djokjakarta operat
Page 39 and 40: UDC 621.395(047.1)LME 82, 83, 84JAC

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