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TXE
TXE, (telephone exchange electronic) was a family of telephone exchanges developed by the British General Post Office (GPO), designed to replace the ageing Strowger switch, Strowger systems. When World War II ended, the UK telephone exchange suppliers supported the GPO's decision to stay with Strowger until a viable electronic system became available. The GPO largely did this to protect their success in the export market, but it actually had the effect of ultimately destroying it. This allowed competitors to develop their own improved switching systems ahead of the GPO. In 1960 the situation rapidly changed when the Australian Postmaster-General's Department rejected a system from a consortium of British manufacturers who offered a register-controlled version of a motor-uniselector system in favour of a crossbar switch, crossbar system from Ericcson, LM Ericsson. Suddenly the rules had changed and the race was on to develop an electronic telephone exchange that could operate with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jim Warman
Bloomfield James Warman (25 July 1924 – 21 November 1984) was an England, English electrical engineer. He was involved with the design of electronic telephone exchanges in the 1960s and 1970s. He was responsible for the concept of both the TXE1 and TXE3 systems, which were reed switch-based electronic exchanges. The development of these exchanges was carried out by a consortium of British telecom manufacturers in conjunction with the General Post Office. The ideas in these exchanges were later developed, by others, into the TXE4 exchanges - which, at their peak in the early 1990s, catered for more than 25% of the UK subscribers. Warman was born at Westcombe Park in South London. During World War II he served in the Royal Electrical and Mechanical Engineers. His career started off Siemens Brothers at Woolwich, and he remained there when Associated Electrical Industries (AEI) took over the company. AEI was then taken over by the General Electric Company, who, in 1968, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPO Telephones
The General Post Office (GPO) of the United Kingdom carried the sole responsibility for providing telecommunication services across the country with the exception of Hull. The GPO issued a range of telephone instruments to telephone service subscribers that were matched in function and performance to its telephone exchanges. General history Until 1982 the GPO had a monopoly on the provision of all telephone lines and telephones within the UK, other than in Kingston upon Hull, and so the range was limited. Customers (known within the GPO as "subs", being short for 'subscribers') did not buy their telephones, they were rented from the GPO, together with the house wiring and the wiring connecting the house to the local network at a connection point known as a DP (distribution point). The majority of DPs were (and still are) at the top of what are still known in the UK as telegraph poles. Type 121 During the early days of telephones, in the UK, a variety of instruments were produce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reed Relay
A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them. Sealed in a long, narrow glass tube, the contacts are protected from corrosion. The glass envelope may contain multiple reed switches or multiple reed switches can be inserted into a single bobbin and actuate simultaneously. Reed switches have been manufactured since the 1930s. Compared with armature-based relays, reed relays can switch much faster, as the moving parts are small and lightweight, although switch bounce is still present. Also, they require less operating power and have lower contact capacitance. Their current handling capacity is limited but, with appropriate contact materials, they are suitable for "dry" switching applications. They are mechanically simple, making for reliability and long life. Memory device A few million reed relays were used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. Often, a ''central office'' is defined as a building used to house the inside plant equipment of potentially several telephone exchanges, each serving a certain geographical area. Such an area has also been referred to as the exchange or exchange area. In North America, a central office location may also be identified as a ''wire center'', designating a facility to which a telephone is connected and obtains dial tone. For business and billing purposes, telecommunication carriers defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System X (telephony)
System X is the digital switching system installed in telephone exchanges throughout the United Kingdom, from 1980 onwards. History Development System X was developed by the Post Office (later to become British Telecom), GEC, Plessey, and Standard Telephones and Cables (STC), and was first shown in public in 1979 at the Telecom 79 exhibition in Geneva, Switzerland. STC withdrew from the project in 1982. In 1988, the telecommunications divisions of GEC and Plessey merged to form GPT, with Plessey subsequently being bought out by GEC and Siemens. In the late 1990s, GEC acquired Siemens' 40% stake in GPT. GEC renamed itself Marconi in 1999. When Marconi was sold to Ericsson in January 2006, Telent plc retained System X and continues to support and develop it as part of its UK services business. Implementation The first System X unit to enter public service was in September 1980 and was installed in Baynard House, London and was a 'tandem junction unit' which switched tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Post Office
The General Post Office (GPO) was the state postal system and telecommunications carrier of the United Kingdom until 1969. Before the Acts of Union 1707, it was the postal system of the Kingdom of England, established by Charles II in 1660. Similar General Post Offices were established across the British Empire. In 1969 the GPO was abolished and the assets transferred to The Post Office, changing it from a Department of State to a statutory corporation. In 1980, the telecommunications and postal sides were split prior to British Telecommunications' conversion into a totally separate publicly owned corporation the following year as a result of the British Telecommunications Act 1981. For the more recent history of the postal system in the United Kingdom, see the articles Royal Mail and Post Office Ltd. Originally, the GPO was a state monopoly covering the dispatch of items from a specific sender to a specific receiver, which was to be of great importance when new forms of co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossbar Switch
In electronics and telecommunications, a crossbar switch (cross-point switch, matrix switch) is a collection of switches arranged in a matrix configuration. A crossbar switch has multiple input and output lines that form a crossed pattern of interconnecting lines between which a connection may be established by closing a switch located at each intersection, the elements of the matrix. Originally, a crossbar switch consisted literally of crossing metal bars that provided the input and output paths. Later implementations achieved the same switching topology in solid-state electronics. The crossbar switch is one of the principal telephone exchange architectures, together with a rotary switch, memory switch, and a crossover switch. General properties A crossbar switch is an assembly of individual switches between a set of inputs and a set of outputs. The switches are arranged in a matrix. If the crossbar switch has M inputs and N outputs, then a crossbar has a matrix with ''M'' × ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plessey
The Plessey Company plc was a British electronics, defence and telecommunications company. It originated in 1917, growing and diversifying into electronics. It expanded after World War II by acquisition of companies and formed overseas companies. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index. In 1989, it was taken over by a consortium formed by GEC and Siemens which split the assets of the Plessey group. The majority of Plessey's defence assets were amalgamated into BAE Systems in 1999 when British Aerospace merged with the defence arm of GEC, Marconi Electronic Systems (MES). A small portion of the defence market, mostly embedded electronic systems and circuitcards remained with GE, formerly GE Fanuc and GE Intelligent Platforms (GE-IP) and now Abaco Systems based in Huntsville, Alabama, and in Towcester, Northamptonshire. The bulk of Plessey's telecommunications assets were acquired by Ericsson through its 2005 acquisition of Marconi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dollis Hill
Dollis Hill is an area in northwest London, which consists of the streets surrounding the 35 hectares (86 acres) Gladstone Park. It is served by a London Underground station, Dollis Hill, on the Jubilee line, providing good links to central London. It is in the London Borough of Brent, close to Willesden Green, Neasden and Cricklewood, and is in the postal districts of NW2 and NW10. The area is mainly residential (Edwardian terraced and 1920s/30s semi-detached houses) with a restaurant, greengrocer and convenience stores near the underground station. The Dollis Hill ward has the highest Irish population in London. Dollis Hill played a part in the Second World War as the code-breaking computer used at Bletchley Park was built at the Post Office Research Station in Dollis Hill and the rarely used alternative Cabinet War Room bunker for Winston Churchill's government was dug underground here. History The Dollis Hill Estate was formed in the early 19th century, when the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Y
System Y is the terminology used by BT, the main operator of the telephone network in the United Kingdom, to refer to the Ericsson AXE digital switching system. In the mid-1980s, British Telecom chose the well established AXE10 digital switch to provide competition for System X developed by a consortium of Plessey, General Electric Company (GEC) (companies later combined as GPT), STC and BT's state owned predecessor, the GPO. The newly privatised BT brought in Ericsson as a competitive alternative supplier ending Plessey/GEC's monopoly on the provision of switching systems. Initially, the AXE systems installed in the UK were partially locally manufacturered in partnership with Thorn EMI and later directly by Ericsson. While System X exchanges were more widespread in BT's network, AXE10 (and subsequent versions) remain common in the classic BT PSTN until their eventual replacement when the network is closed, which at the time of the writing is expected to be in 2025 AXE10 cove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blackheath, London
Blackheath is an area in Southeast London, straddling the border of the Royal Borough of Greenwich and the London Borough of Lewisham. It is located northeast of Lewisham, south of Greenwich and southeast of Charing Cross, the traditional centre of London. The area southwest of its station and in its ward is named Lee Park. Its northern neighbourhood of Vanbrugh Park is also known as St John's Blackheath and despite forming a projection has amenities beyond its traditional reach named after the heath. To its west is the core public green area that is the heath and Greenwich Park, in which sit major London tourist attractions including the Greenwich Observatory and the Greenwich Prime Meridian. Blackheath railway station is south of the heath. History Etymology ;Records and meanings The name is from Old English spoken words 'blæc' and 'hǣth'. The name is recorded in 1166 as ''Blachehedfeld'' which means "dark, or black heath field" – field denotes an enclosure or clear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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