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General Radio
General Radio Company (later, GenRad) was a broad-line manufacturer of electronic test equipment in Massachusetts, U.S. from 1915 to 2001. History On June 14, 1915, Melville Eastham and a small group of investors started General Radio Company in Cambridge, Massachusetts, a few blocks northwest of Massachusetts Institute of Technology. During the 1950s, the company moved to West Concord, Massachusetts, where it became a major player in the automatic test equipment (ATE) business, manufacturing a line of testers for assembled printed circuit boards. It also produced extensive lines of electrical component measuring equipment, sound and vibration measurement and RLC standards. In 1975, the company name was changed to GenRad. In 1991, a startup QuadTech was founded as spinoff of GenRad's Instrumentation division and Precision Product lines, as well as the rights to use the "GenRad" and "General Radio" names. In 2000, IET Labs acquired from QuadTech the GenRad RLC standards, imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vintage Audio-Frequency Microvolter, General Radio Co
Vintage, in winemaking, is the process of picking grapes and creating the finished product—wine (see Harvest (wine)). A vintage wine is one made from grapes that were all, or primarily, grown and harvested in a single specified year. In certain wines, it can denote quality, as in Port wine, where Port houses make and declare vintage Port in their best years. From this tradition, a common, though not strictly correct, usage applies the term to any wine that is perceived to be particularly old or of a particularly high quality. Most countries allow a vintage wine to include a portion of wine that is not from the year denoted on the label. In Chile and South Africa, the requirement is 75% same-year content for vintage-dated wine. In Australia, New Zealand, and the member states of the European Union, the requirement is 85%. In the United States, the requirement is 85%, unless the wine is designated with an AVA, (e.g., Napa Valley), in which case it is 95%. Technically, the 85% r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductance
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the current, and follows any changes in current. From Faraday's law of induction, any change in magnetic field through a circuit induces an electromotive force (EMF) (voltage) in the conductors, a process known as electromagnetic induction. This induced voltage created by the changing current has the effect of opposing the change in current. This is stated by Lenz's law, and the voltage is called ''back EMF''. Inductance is defined as the ratio of the induced voltage to the rate of change of current causing it. It is a proportionality factor that depends on the geometry of circuit conductors and the magnetic permeability of nearby materials. An electronic component designed to add inductance to a circuit is called an inductor. It typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1915 Establishments In Massachusetts
Events Below, the events of World War I have the "WWI" prefix. January *January – British physicist Sir Joseph Larmor publishes his observations on "The Influence of Local Atmospheric Cooling on Astronomical Refraction". *January 1 ** WWI: British Royal Navy battleship HMS ''Formidable'' is sunk off Lyme Regis, Dorset, England, by an Imperial German Navy U-boat, with the loss of 547 crew. **Battle of Broken Hill: A train ambush near Broken Hill, New South Wales, Australia, is carried out by two men (claiming to be in support of the Ottoman Empire) who are killed, together with 4 civilians. * January 5 – Joseph E. Carberry sets an altitude record of , carrying Capt. Benjamin Delahauf Foulois as a passenger, in a fixed-wing aircraft. * January 12 ** The United States House of Representatives rejects a proposal to give women the right to vote. ** '' A Fool There Was'' premières in the United States, starring Theda Bara as a ''femme fatale''; she quickly becomes one o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics Companies Established In 1915
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow. Electronics has hugely influenced the development of modern society. The central driving force behind the entire electronics industry is the semiconductor industry sector, which has annual sales of over $481 billion as of 2018. The largest industry sector is e-commerce, which generated over $29 trillion in 2017. History and development Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics Companies Of The United States
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow. Electronics has hugely influenced the development of modern society. The central driving force behind the entire electronics industry is the semiconductor industry sector, which has annual sales of over $481 billion as of 2018. The largest industry sector is e-commerce, which generated over $29 trillion in 2017. History and development Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon Standard Identification Number
An Amazon Standard Identification Number (ASIN) is a 10-character alphanumeric unique identifier assigned by Amazon.com and its partners for product identification within the Amazon organization. They were originated in 1996 by Rebecca Allen, an Amazon software engineer, when it became clear that Amazon was going to sell products other than just books. The 10-character format of the ASIN was adopted so that Amazon databases and software, which were designed to expect a 10-character International Standard Book Number (ISBN) field, would not have to be changed to accommodate the new identification format. Usage and structure Each product sold on Amazon.com is given a unique ASIN. For books with a 10-digit International Standard Book Number (ISBN), the ASIN and the ISBN are the same. The Kindle edition of a book will not use its ISBN as the ASIN, although the electronic version of a book may have its own ISBN. The ASIN forms part of the URL of a product detail page on Amazon's webs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Worldwide Diagnostic System
Worldwide may refer to: * Pertaining to the entire world * Worldwide (rapper) (born 1986), American rapper * Pitbull (rapper) (born 1981), also known as Mr. Worldwide, American rapper * ''Worldwide'' (Audio Adrenaline album), 2003 * ''Worldwide'' (The Death Set album), 2016 * ''Worldwide'' (Everything but the Girl album), 1991 * "Worldwide", a song by Big Time Rush from ''BTR'', 2010 * "World Wide (Remix)", a song by Outlawz from ''Novakane'', 2001 * World-Wide Shipping, a Hong Kong-based shipping company that merged with Norwegian company Bergesen to form BW Group * Worldwide magazine, a magazine for the Austin Motor Company by the in-house Nuffield Press See also * Cosmopolitanism * International (other) * Global (other) * World (other) The world is a common name for the whole of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth. World, worlds or the world may also refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Kilton Clapp
James Kilton Clapp (December 30, 1897 – 1965) was an American electrical engineer who worked for General Radio Corporation. He was born in Denver, Colorado and graduated from Massachusetts Institute of Technology in 1923, obtaining a master's degree there in 1926. He taught at MIT and then joined General Radio Corporation in 1928, until his retirement in 1957. He became a member of the IRE in 1928 and in 1933 was named "Fellow". Several of Clapp's inventions became the basis of General Radio products. He invented a quartz-crystal oscillator frequency standard in 1930, and patented a temperature control oven for crystal oscillators. Clapp's name is best known in the field of electronics for his description in 1948 of an improved form of Colpitts oscillator known as the Clapp oscillator The Clapp oscillator or Gouriet oscillator is an LC electronic oscillator that uses a particular combination of an inductor and three capacitors to set the oscillator's frequency. LC oscillator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GR Connector
The GR connector, officially the General Radio Type 874, was a type of RF connector used for connecting coaxial cable. Designed by Eduard Karplus, Harold M. Wilson and William R. Thurston at General Radio Corporation. It was widely used on General Radio's electronic test equipment and some Tektronix instruments from the 1950s to the 1970s. The connector had several desirable properties: * Good control of the electrical impedance across a wide range of frequencies, therefore low reflection * Reliable mating * Hermaphrodism, so there were no "male" or "female" connectors; any GR connector could mate with any other GR connector. This last characteristic was achieved by having both the inner and outer conductors made from four leaves, two of which were displaced slightly outwards and two of which were displaced slightly inwards. By rotating one connector by 90 degrees, its inner leaves would mate with the other connector's outer leaves and vice versa. When frequently mated, the inne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binding Post
A binding post is a connector commonly used on electronic test equipment to terminate (attach) a single wire or test lead. They are also found on loudspeakers and audio amplifiers as well as other electrical equipment. History A binding post contains a central threaded metal rod and a cap that screws down on that rod. Binding posts slowly evolved from 19th century general purpose fasteners into 20th century electrical binding posts. Examples of binding posts used during the 19th century are telegraph key and blasting machine devices. Caps are commonly insulated with plastic and color-coded: red commonly means an active or positive terminal; black indicates an inactive (reference or return) or negative terminal; and green indicates an earth (ground) terminal. Caps during the 19th century were typically bare metal until synthetic plastic, such as Bakelite, became available in the early 20th century. During the late 1940s, General Radio created a new binding post that had a j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autotransformer
An autotransformer is an electrical transformer with only one winding. The "auto" (Greek for "self") prefix refers to the single coil acting alone, not to any kind of automatic mechanism. In an autotransformer, portions of the same winding act as both the primary winding and secondary winding sides of the transformer. In contrast, an ordinary transformer has separate primary and secondary windings which have no metallic conducting path between them. The autotransformer winding has at least three taps where electrical connections are made. Since part of the winding does "double duty", autotransformers have the advantages of often being smaller, lighter, and cheaper than typical dual-winding transformers, but the disadvantage of not providing electrical isolation between primary and secondary circuits. Other advantages of autotransformers include lower leakage reactance, lower losses, lower excitation current, and increased VA rating for a given size and mass. An example of an ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Level Meter
A sound level meter (also called sound pressure level meter (SPL)) is used for acoustic measurements. It is commonly a hand-held instrument with a microphone. The best type of microphone for sound level meters is the condenser microphone, which combines precision with stability and reliability. The diaphragm of the microphone responds to changes in air pressure caused by sound waves. That is why the instrument is sometimes referred to as a sound pressure level meter (SPL). This movement of the diaphragm, i.e. the sound pressure (unit pascal, Pa), is converted into an electrical signal (unit volt, V). While describing sound in terms of sound pressure, a logarithmic conversion is usually applied and the sound pressure ''level'' is stated instead, in decibels (dB), with 0 dB SPL equal to 20 micropascals. A microphone is distinguishable by the voltage value produced when a known, constant root mean square sound pressure is applied. This is known as microphone sensitivity. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
