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Sound-powered Telephone
A sound-powered telephone is a communication device that allows users to talk to each other with the use of a handset, similar to a conventional telephone, but without the use of external power. This technology has been used since at least 1944 for both routine and emergency communication on ships to allow communication between key locations on a vessel if power is unavailable. A sound-powered phone circuit can have two or more stations on the same circuit. The circuit is always live, thus a user begins speaking rather than dialing another station. Sound-powered telephones are not normally connected to a telephone exchange. Operation The microphone transducer converts sound pressure from a user's voice into an electric current, which is then converted back to sound by a transducer at the receiver nodes. The most significant distinction between ordinary telephones and sound-powered telephones is in the operation of the microphone. Since the microphones used in most teleph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMNZS Te Kaha Sound-powered Telephone 20080702
His or Her Majesty's New Zealand Ship (HMNZS) is the ship prefix used to identify warships and shore facilities commissioned into the Royal New Zealand Navy (RNZN). It derives from "His Majesty's Ship" (HMS) used in the United Kingdom. The British monarch is also equally and separately the Monarchy in New Zealand, New Zealand head of state. Should the monarch be female, the designation also changes to "Her" rather than "His" Majesty. On 1 October 1941, George VI of the United Kingdom, King George VI fixed his signature to the approval for the Royal New Zealand Navy and from that date all ships officially received the designation. See also *List of ships of the Royal New Zealand Navy Royal New Zealand Navy Ship prefixes {{NewZealand-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Outage
A power outage (also called a powercut, a power out, a power failure, a power blackout, a power loss, or a blackout) is the loss of the electrical power network supply to an end user. There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage to electric transmission lines, substations or other parts of the distribution system, a short circuit, cascading failure, fuse or circuit breaker operation. Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, sewage treatment plants, and mines will usually have backup power sources such as standby generators, which will automatically start up when electrical power is lost. Other critical systems, such as telecommunication, are also required to have emergency power. The battery room of a telephone exchange usually has arrays of lead–acid batteries for backup and also a socket ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, multi-mission service unique among the United States military branches for having a maritime law enforcement mission with jurisdiction in both domestic and international waters and a federal regulatory agency mission as part of its duties. It is the largest and most powerful coast guard in the world, rivaling the capabilities and size of most navies. The U.S. Coast Guard is a humanitarian and security service. It protects the United States' borders and economic and security interests abroad; and defends its sovereignty by safeguarding sea lines of communication and commerce across vast territorial waters spanning 95,000 miles of coastline and its Exclusive Economic Zone. With national and economic security depending upon open global trade a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combat Information Center
A combat information center (CIC) or action information centre (AIC) is a room in a warship or AWACS aircraft that functions as a tactical center and provides processed information for command and control of the near battlespace or area of operations. Within other military commands, rooms serving similar functions are known as command centers. Regardless of the vessel or command locus, each CIC organizes and processes information into a form more convenient and usable by the commander in authority. Each CIC funnels communications and data received over multiple channels, which is then organized, evaluated, weighted and arranged to provide ordered timely information flow to the battle command staff under the control of the CIC officer and his deputies. Overview CICs are widely depicted in film and television treatments, frequently with large maps, numerous computer consoles and radar and sonar repeater displays or consoles, as well as the almost ubiquitous grease-pencil annota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lookout
A lookout or look-out is a person in charge of the observation of hazards. The term originally comes from a naval background, where lookouts would watch for other ships, land, and various dangers. The term has now passed into wider parlance. Naval application Lookouts have been traditionally placed in high on masts, in crow's nests and tops. The International Regulations for Preventing Collisions at Sea (1972) says in part: : Every vessel must at all times keep a proper look-out by sight (day shape or lights by eyes or visual aids), hearing (sound signal or Marine VHF radio) and all available means (e.g. Radar, ARPA, AIS, GMDSS...) in order to judge if risk of collision exists. Lookouts report anything they see and or hear. When reporting contacts, lookouts give information such as, bearing of the object, which way the object is headed, target angles and position angles and what the contact is. Lookouts should be thoroughly familiar with the various types of distress signa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of its active battle fleet alone exceeding the next 13 navies combined, including 11 allies or partner nations of the United States as of 2015. It has the highest combined battle fleet tonnage (4,635,628 tonnes as of 2019) and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction, and five other carriers planned. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the United States Navy is the third largest of the United States military service branches in terms of personnel. It has 290 deployable combat vessels and more than 2,623 operational aircraft . The United States Navy traces its origins to the Continental Navy, which was established during the American Revo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Powered Telephone
A sound-powered telephone is a communication device that allows users to talk to each other with the use of a handset, similar to a conventional telephone, but without the use of external power. This technology has been used since at least 1944 for both routine and emergency communication on ships to allow communication between key locations on a vessel if power is unavailable. A sound-powered phone circuit can have two or more stations on the same circuit. The circuit is always live, thus a user begins speaking rather than dialing another station. Sound-powered telephones are not normally connected to a telephone exchange. Operation The microphone transducer converts sound pressure from a user's voice into an electric current, which is then converted back to sound by a transducer at the receiver nodes. The most significant distinction between ordinary telephones and sound-powered telephones is in the operation of the microphone. Since the microphones used in most telepho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Magneto
A telephone magneto is a hand-cranked electrical generator that uses permanent magnets to produce alternating current from a rotating armature. In early telegraphy, magnetos were used to power instruments, while in telephony they were used to generate electrical current to drive electromechanical ringers in telephone sets and activate signals on operator consoles. Telegraphy Telegraphy pre-dated telephony and magnetos were used to drive some of the early printing telegraph instruments. Manual telegraphy with keys and reception by either a needle instrument or a syphon recorder could be powered by batteries. The later automatic and printing instruments, such as the Wheatstone ABC telegraph, required greater currents that could be delivered by a hand-cranked magneto. A hand-crank was used to rotate a belt drive that increases the rotational speed of an armature with a pair of coils between the poles of a stationary horseshoe magnet. Telephony Many early manual telephones had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication
Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquiry studying them. There are many disagreements about its precise definition. John Peters argues that the difficulty of defining communication emerges from the fact that communication is both a Universality (philosophy), universal phenomenon and a Communication studies, specific discipline of institutional academic study. One definitional strategy involves limiting what can be included in the category of communication (for example, requiring a "conscious intent" to persuade). By this logic, one possible definition of communication is the act of developing Semantics, meaning among Subject (philosophy), entities or Organization, groups through the use of sufficiently mutually understood signs, symbols, and Semiosis, semiotic conventions. An im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headphones
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air for anyone nearby to hear. Headphones are also known as earspeakers, earphones or, colloquially, cans. Circumaural ('around the ear') and supra-aural ('over the ear') headphones use a band over the top of the head to hold the speakers in place. Another type, known as earbuds or earpieces consist of individual units that plug into the user's ear canal. A third type are bone conduction headphones, which typically wrap around the back of the head and rest in front of the ear canal, leaving the ear canal open. In the context of telecommunication, a headset is a combination of headphone and microphone. Headphones connect to a signal source such as an audio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
