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Switchhook
A telephone hook or switchhook is an electrical switch which indicates when the phone is hung up, often with a lever or magnetic button inside the cradle or base where a telephone handset resides. It takes its name from old wooden wall telephones and candlestick telephones, where the mouthpiece was mounted on the telephone box and, due to sidetone considerations, the receiver was separate, on a cable. When the telephone was not in use, the receiver was hung on a spring-loaded hook; its weight would cause the hook to swing down and open an electrical contact, disconnecting something, but not the telephone from the line or the phone could not ring. When the handset is on the cradle, the telephone is said to be "on-hook", or ready for a call. When the handset is off the cradle, the telephone is said to be "off-hook", or unable to receive any (further) calls. Pushing the switchhook quickly is termed a "hook flash". Purpose Telephone switchhook separates calling and transmitting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Off-hook
In telephony, on-hook and off-hook are two states of a communication circuit. On subscriber telephones the states are produced by placing the handset onto or off the hookswitch. Placing the circuit into the off-hook state is also called ''seizing the line''. ''Off-hook'' originally referred to the condition that prevailed when telephones had a separate earpiece (''receiver''), which hung from its switchhook until the user initiated a telephone call by removing it. When off hook the weight of the receiver no longer depresses the spring-loaded switchhook, thereby connecting the instrument to the telephone line. Off-hook The term off-hook has the following meanings: * The condition that exists when a telephone or other user instrument is in use, i.e., during dialing or communicating. * A general description of one of two possible signaling states at an interface between telecommunications systems, such as tone or no tone and ground connection versus battery connection. Note that if ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On-hook
In telephony, on-hook and off-hook are two states of a communication circuit. On subscriber telephones the states are produced by placing the handset onto or off the hookswitch. Placing the circuit into the off-hook state is also called ''seizing the line''. ''Off-hook'' originally referred to the condition that prevailed when telephones had a separate earpiece (''receiver''), which hung from its switchhook until the user initiated a telephone call by removing it. When off hook the weight of the receiver no longer depresses the spring-loaded switchhook, thereby connecting the instrument to the telephone line. Off-hook The term off-hook has the following meanings: * The condition that exists when a telephone or other user instrument is in use, i.e., during dialing or communicating. * A general description of one of two possible signaling states at an interface between telecommunications systems, such as tone or no tone and ground connection versus battery connection. Note that if ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hook Flash
On analog telephone lines with special services, a flash or register-recall signal is used to control functions on the public telephone exchange, PBX or VoIP ATA. The term "register-recall" in Europe refers to sending a discrete signal to alert the "register" — the logical system controlling a telephone exchange, that it should accept commands from the end user in the middle of a call. The register was normally disconnected from the circuit once a call was setup. In contemporary telephone systems, the functions of the register are carried out by software and computer hardware, but in previous generations of electromechanical exchanges, using technology such crossbar or Reed relay, the register was often a system of analog electronics or even relay logic. The term "Flash" or "Hook Flash" is commonly used in North America, while in Europe a similar signal is referred to as a register-recall or more commonly "Recall" or simply the "R" button. These signals perform similar functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from el, τῆλε (''tēle'', ''far'') and φωνή (''phōnē'', ''voice''), together meaning ''distant voice''. A common short form of the term is ''phone'', which came into use early in the telephone's history. In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business, government, and in households. The essential elements of a telephone are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfsonian-FIU Museum - IMG 8151
The Wolfsonian–Florida International University or The Wolfsonian-FIU, located in the heart of the Art Deco District of Miami Beach, Florida, is a museum, library and research center that uses its collection to illustrate the persuasive power of art and design. For fifteen years, The Wolfsonian has been a division within Florida International University. The Wolfsonian's two collections comprise approximately 180,000 pieces from the period 1885 to 1945 — the height of the Industrial Revolution until the end of the Second World War — in a variety of media, including: furniture; industrial-design objects; works in glass; ceramics; metal; rare books; periodicals; ephemera; works on paper; paintings; textiles; and medals. The museum is an affiliate within the Smithsonian Affiliations program, sharing affiliation with the Frost Art Museum. The countries most strongly represented are Germany, Great Britain, Italy, the Netherlands, and the United States. There are also significant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candlestick Telephone
The candlestick telephone (or pole telephone) is a style of telephone that was common from the late 1890s to the 1940s. A candlestick telephone is also often referred to as a desk stand, an upright, or a stick phone. Candlestick telephones featured a mouth piece (transmitter) mounted at the top of the stand, and a receiver (ear phone) that was held by the user to the ear during a call. When the telephone was not in use, the receiver rested in the fork of the switch hook protruding to the side of the stand, thereby disconnecting the audio circuit from the telephone network. Design and features Candlestick telephones were designed with varying features. Most recognizable, candlesticks featured a base with a vertical cylindrical neck extending upright for up to in length. At the top of the stand was mounted a carbon microphone (''transmitter'') to speak into, and a switch hook extending sideways upon which an ear piece (''receiver'') was hung. To make or answer a telephone call, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidetone
Sidetone is audible feedback to someone speaking or otherwise producing sound as an indication of active transmission. Sidetone is introduced by some communications circuits and anti-sidetone circuitry is used to control its level. Sidetone is expected behavior for telephone systems. Absence of sidetone can cause users to believe the call has been dropped or cause them to speak loudly. Too much sidetone can cause users to speak softly. Telephony In telephony, sidetone is the effect of sound picked up by the telephone's transmitter (mouthpiece) and instantly introduced at a low electronic signal level into the receiver (earpiece) of the same handset, a form of electrical feedback through the telephone hybrid.AT&T, ''Bell System Practices'', Section C30.001 Issue 1 (March 16, 1932) ''Common Battery Anti-Sidetone Stations'' Sidetone in early 19th century telephones was strong due to the type of circuit used in instruments. Anti-sidetone circuitry in the telephone hybrid brought sideto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transceiver
In radio communication, a transceiver is an electronic device which is a combination of a radio ''trans''mitter and a re''ceiver'', hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. These two related functions are often combined in a single device to reduce manufacturing costs. The term is also used for other devices which can both transmit and receive through a communications channel, such as ''optical transceivers'' which transmit and receive light in optical fiber systems, and ''bus transceivers'' which transmit and receive digital data in computer data buses. Radio transceivers are widely used in wireless devices. One large use is in two-way radios, which are audio transceivers used for bidirectional person-to-person voice communication. Examples are cell phones, which transmit and receive the two sides of a phone conversation using radio waves to a cell tower, cordless phones in which both the phone handset and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas A
Thomas may refer to: People * List of people with given name Thomas * Thomas (name) * Thomas (surname) * Saint Thomas (other) * Thomas Aquinas (1225–1274) Italian Dominican friar, philosopher, and Doctor of the Church * Thomas the Apostle * Thomas (bishop of the East Angles) (fl. 640s–650s), medieval Bishop of the East Angles * Thomas (Archdeacon of Barnstaple) (fl. 1203), Archdeacon of Barnstaple * Thomas, Count of Perche (1195–1217), Count of Perche * Thomas (bishop of Finland) (1248), first known Bishop of Finland * Thomas, Earl of Mar (1330–1377), 14th-century Earl, Aberdeen, Scotland Geography Places in the United States * Thomas, Illinois * Thomas, Indiana * Thomas, Oklahoma * Thomas, Oregon * Thomas, South Dakota * Thomas, Virginia * Thomas, Washington * Thomas, West Virginia * Thomas County (other) * Thomas Township (other) Elsewhere * Thomas Glacier (Greenland) Arts, entertainment, and media * ''Thomas'' (Burton novel) 1969 nove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hilborne Roosevelt
Hilborne Lewis Roosevelt (December 21, 1849 – December 30, 1886) was a pioneering organ builder, telecommunication engineer, and a member of the Roosevelt family. Life Roosevelt was born in New York City to Silas Weir Roosevelt, a son of Cornelius Roosevelt and Mary West. He was thus a cousin of Presidents Theodore Roosevelt and Franklin D. Roosevelt. Roosevelt did not take to either business or politics, the traditional Roosevelt family occupations. Instead, he was musically and mechanically inclined and wanted to be an organ builder from early childhood, entering an apprenticeship at an organ factory. He later traveled to Europe for further training in the field. His relatives frowned upon a mechanical occupation, but when he began to make money, his family was reassured. Roosevelt was particularly interested in the electric action organ, and was one of the first to study the application of new electrical devices to the manufacture of organ actions. He took out the first p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edwin Holmes (inventor)
Edwin Holmes (April 25, 1820 – 1901)John Fischer, DGA Security Systems, Inc. Updated May 5, 2010 was an American businessman who is credited with inventing, commercializing the electromagnetic burglar alarm and with establishing the first burglar alarm networks. Biography Holmes was born in West Boylston, Massachusetts, to Sally Graves and Thomas Holmes. His father was from New Hampshire where he served as the town postmaster. Holmes married Eliza Ann Richardson. They had four children (two boys and two girls). One girl was Titanic survivor Ella Holmes White. Edwin started his business in 1849 in Boston, as a seller of household items and entrepreneur, and acquired skills which later helped him in establishing the burglar alarm industry. Burglar alarm The alarm was patented in 1853 by the Reverend Augustus Russell Pope (1819–1858) of Somerville, Massachusetts. Edwin Holmes acquired Pope's patent rights in 1857 for US$1500 and manufactured the device in his factory in Bost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Off The Hook (radio Program)
''Off the Hook'' is a hacker-oriented weekly talk radio program, hosted by Emmanuel Goldstein, which focuses on the societal ramifications of information technology and the laws that regulate how people use them. It airs Wednesday nights at 8:00 p.m. Eastern Time in New York City on the community radio station WBAI 99.5 FM. It is also simulcast online via streaming MP3, rebroadcast on various other radio stations, and has been made available as a podcast (since long before that term was coined). History Premiere ''Off the Hook'' first aired on Thursday, October 7, 1988. It was originally set to debut Friday, August 12, 1988, but a fire on the radio transmitter floor of the Empire State Building forced a postponement. Notable events Some notable events in the program's history include: * On November 30, 1999, journalist Amy Goodman reported live from the World Trade Organization protests, while being repeatedly approached by police and tear-gassed. * As an April Fool's Day p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
