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George Sweigert
George H. Sweigert (1920–1999) is credited as the first inventor to patent the cordless telephone. Born in Akron, Ohio, Sweigert served five years in the US Army as a radio operator in World War II in Guadalcanal, Bougainville, Fiji and New Georgia assigned to the 145th Headquarters Company under the 37th Infantry Division (United States). Following the war, Sweigert attended Bowling Green State University near Toledo, Ohio. Sweigert credited his military experience for invention of the cordless telephone, citing experimentation with various antennas, signal frequencies, and types of radios. Radio telephone With the patent application submitted on May 2, 1966 to the US Patent and Trademark Office, Sweigert submitted a working model of the phone in addition to the required description. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Plain Dealer
''The Plain Dealer'' is the major newspaper of Cleveland, Ohio, United States. In fall 2019, it ranked 23rd in U.S. newspaper circulation, a significant drop since March 2013, when its circulation ranked 17th daily and 15th on Sunday. As of May 2019, ''The Plain Dealer'' had 94,838 daily readers and 171,404 readers on Sunday. ''The Plain Dealers media market, the Cleveland-Akron Designated Market Area, has a population of 3.8 million people, making it the 19th-largest market in the United States. In August 2013, ''The Plain Dealer'' reduced home delivery to four days a week, including Sunday. A daily version of ''The Plain Dealer'' is available electronically as well as in print at stores, newspaper vending machine, newsracks and newsstands. History Founding The newspaper was established in January 1842 when two brothers, Joseph William Gray and Admiral Nelson Gray, took over ''The Cleveland Advertiser'' and changed its name to ''The Plain Dealer''. ''The Cleveland Advertise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Coil
An induction coil or "spark coil" ( archaically known as an inductorium or Ruhmkorff coil after Heinrich Rühmkorff) is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply. p.98 To create the flux changes necessary to induce voltage in the secondary coil, the direct current in the primary coil is repeatedly interrupted by a vibrating mechanical contact called an interrupter. Invented in 1836 by Nicholas Callan, with additional research by Charles Grafton Page and others, the induction coil was the first type of transformer. It was widely used in x-ray machines, spark-gap radio transmitters, arc lighting and quack medical electrotherapy devices from the 1880s to the 1920s. Today its only common use is as the ignition coils in internal combustion engines and in physics education to demonstrate induction. Construction and function An induction coil consists of two coils of insulated wire wound around a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplifiers
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the voltage or current ( power, voltage or current amplifier). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a greater amplitude signal at its output. The ratio of output to input voltage, current, or power is termed gain (voltage, current, or power gain). An amplifier, by definition has gain greater than unity (if the gain is less than unity, the device is an attenuator). An amplifier can either be a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Full Duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX). In a full-duplex system, both parties can communicate with each other simultaneously. An example of a full-duplex device is plain old telephone service; the parties at both ends of a call can speak and be heard by the other party simultaneously. The earphone reproduces the speech of the remote party as the microphone transmits the speech of the local party. There is a two-way communication channel between them, or more strictly speaking, there are two communication chann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Inventors Hall Of Fame
The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also operates a museum in Alexandria, Virginia, sponsors educational programs, and a collegiate competition. As of 2020, 603 inventors have been inducted, mostly constituting historic persons from the past three centuries, but including about 100 living inductees. Nominees must hold a U.S. patent of significant contribution to the U.S. welfare, and which advances science and useful arts. The 2020 class included 22 inventors. History The National Inventors Hall of Fame was founded in 1973 on the initiative of H. Hume Mathews, then the chairman of the National Council of Patent Law Associations (now the National Council of Intellectual Property Law Associations). It was launched by Ed Sobey, who was also the first director. In 1974, it gained a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
