Telephone sockets

Ultradur Highspeed nanopolymer modified PBT (BASF) is used to manufacture a telephone socket. 

Table 14.11 Telephone Socket Terminal Identification. Terminals 1 and 6 are Frequently Unused, and Therefore Four-Core Cable May Normally Be Installed. Terminal 4, on the Incoming Exchange Line, Is Only Used on a PBX Line for Earth Recall...

An extension bell may be connected to the installation by connecting the two bell wires to terminals 3 and 5 of a telephone socket. The extension bell must be of the high impedance type having an REN rating. All equipment connected to a BT exchange line must display the green circle of approval. 

Table 3.9 Telephone socket terminal identification. Terminals 1 and 6 are frequently unused, and therefore four-core cable may normally be installed. Terminal 4, on the incoming exchange line, is only used on a PBX line for earth recall...

Typically, polyester resins are used for high-end applications that require excellent electrical and thermal resistance. When dimensional stability under load is more critical, glass fibers are incorporated to increase the heat distortion temperature and the stiffness of the part. Examples of glass fiber reinforced parts include electrical housings, electrical adapters, computer components, telephone housings, and light bulb sockets. When impact modified, polybutylene terephthalate can be injection molded to make car bumpers. 

Apart from the outer boundary the inner boundary, i.e. the degree of detail of the analysis, must be determined. With reference to the telephone example this implies the question whether screws, coils, cables etc. have to be considered or not. Does the analysis have to address the molecular or atomic level or go even further Obviously not. In practical cases the degree of detail is determined by the objective of the analysis. If we intend to find out the consequences of a pump failure, it suffices to consider the pump as a unit. This unit comprises the motor, the impeller, the power transmission and the easing as well as the local control boards and the cables to the sockets in the wall. Should, however, the failure of the pump itself be examined, the piece-parts mentioned must be eonsidered individually or even be broken down to smaller units. 

Sitting rooms will require between six and ten double sockets with one double socket situated next to any telephone outlet to power telecommunication equipment and two double sockets adjacent to the TV aerial outlet for TV, video and DVD supplies. 

Hallways - two double sockets with one situated next to any telephone outlet. 

On new premises the electrical contractor may install sockets and the associated wiring to the point of intended line entry, but the connection of the incoming line to the installed master socket must only be made by the telephone company s engineer. 

On existing installations, additional secondary sockets may be installed to provide an extended plug-in facility as shown in Fig. 14.62. Any number of secondary sockets may be connected in parallel, but the number of telephones which may be cormected at any one time is restricted. 

The multi-core cable used for wiring extension socket outlets should be of a type intended for use with telephone circuits, which will normally be between 0.4 and 0.68 mm in cross-section. Telephone cable conductors are identified in Table 14.10 and the individual terminals in Table 14.11. The conductors should be connected as shown in Fig. 14.62. 

Applications boots, conveyor belts, electrician s gloves, gloves, heels and soles, hoses. Instrument panels, latex foams, machined components, pipes, plugs, pumps, shock absorbers, sockets, storage-battery cases, switchboard panels, telephone receivers, tire cord Impregnation, tires, toys, tubes, valves, vibration dampers, waterproof clothing and bathing apparel, wire and cables ... 

Uses of polycarbonates The electric sector consumes ca. 44 % of the produced PC. Applications are housings for telephones, distribution equipment, lamp sockets, safety switches,... 

PBT is used in E E applications for its electrical insulation properties, good heat resistance and chemical resistance. The main applications or PBT in the electrical and electronics industry include specialist light bulbs and lamp holders, housings for sockets and switches, printed circuit board connectors and sockets, junction boxes, capacitor housings, electronic coimectors, fans and coil formers. Other applications include keytops for telephone keypads and LED displays. 

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