Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other electrically charged particles. Electronics is a subfield of physics and electrical engineering which uses active devices such as transistors, diodes, and integrated circuits to control and amplify the flow of electric current and to convert it from one form to another, such as from alternating current (AC) to direct current (DC) or from analog signals to digital signals.
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal. 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 proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is defined as a circuit that has a power gain greater than one.
Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequencies between 300 MHz and 300 GHz, broadly construed. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz, or between 1 and 3000 GHz . The prefix micro- in microwave is not meant to suggest a wavelength in the micrometer range; rather, it indicates that microwaves are small, compared to the radio waves used in prior radio technology.
A transistor is a semiconductor device used to amplify or switch electrical signals and power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits. Because transistors are the key active components in practically all modern electronics, many people consider them one of the 20th century's greatest inventions.
A vacuum tube, electron tube, valve, or tube is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
Complementary metal–oxide–semiconductor is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions. CMOS technology is used for constructing integrated circuit (IC) chips, including microprocessors, microcontrollers, memory chips, and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors, data converters, RF circuits, and highly integrated transceivers for many types of communication.
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Following the invention of the transistor in 1947—which revolutionized the field of consumer electronics by introducing small but powerful, convenient hand-held devices—the Regency TR-1 was released in 1954 becoming the first commercial transistor radio. The mass-market success of the smaller and cheaper Sony TR-63, released in 1957, led to the transistor radio becoming the most popular electronic communication device of the 1960s and 1970s. Transistor radios are still commonly used as car radios. Billions of transistor radios are estimated to have been sold worldwide between the 1950s and 2012.
Popular Electronics was an American magazine published by John August Media, LLC, and hosted at TechnicaCuriosa.com. The magazine was started by Ziff-Davis Publishing Company in October 1954 for electronics hobbyists and experimenters. It soon became the "World's Largest-Selling Electronics Magazine". In April 1957, Ziff-Davis reported an average net paid circulation of 240,151 copies. Popular Electronics was published until October 1982 when, in November 1982, Ziff-Davis launched a successor magazine, Computers & Electronics. During its last year of publication by Ziff-Davis, Popular Electronics reported an average monthly circulation of 409,344 copies. The title was sold to Gernsback Publications, and their Hands-On Electronics magazine was renamed to Popular Electronics in February 1989, and published until December 1999. The Popular Electronics trademark was then acquired by John August Media, who revived the magazine, the digital edition of which is hosted at TechnicaCuriosa.com, along with sister titles, Mechanix Illustrated and Popular Astronomy.
Lafayette Radio Electronics Corporation was an American radio and electronics manufacturer and retailer from approximately 1931 to 1981, headquartered in Syosset, New York, a Long Island suburb of New York City. The company sold radio sets, Amateur radio (Ham) equipment, citizens band (CB) radios and related communications equipment, electronic components, microphones, public address systems, and tools through their company owned and branded chain of retail outlets and by mail-order.
Forrest M. Mims III is an American amateur scientist, magazine columnist, and author of Getting Started in Electronics and Engineer's Mini-Notebook series of instructional books that were originally sold in Radio Shack electronics stores and are still in print. Mims graduated from Texas A&M University in 1966 with a major in government and minors in English and history. He became a commissioned officer in the United States Air Force, served in Vietnam as an Air Force intelligence officer (1967), and a Development Engineer at the Air Force Weapons Laboratory (1968–70).
An electronic symbol is a pictogram used to represent various electrical and electronic devices or functions, such as wires, batteries, resistors, and transistors, in a schematic diagram of an electrical or electronic circuit. These symbols are largely standardized internationally today, but may vary from country to country, or engineering discipline, based on traditional conventions.
An active-pixel sensor (APS) is an image sensor, which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a photodetector and one or more active transistors. In a metal–oxide–semiconductor (MOS) active-pixel sensor, MOS field-effect transistors (MOSFETs) are used as amplifiers. There are different types of APS, including the early NMOS APS and the now much more common complementary MOS (CMOS) APS, also known as the CMOS sensor. CMOS sensors are used in digital camera technologies such as cell phone cameras, web cameras, most modern digital pocket cameras, most digital single-lens reflex cameras (DSLRs), mirrorless interchangeable-lens cameras (MILCs), and lensless imaging for cells.
Electronics Illustrated was an American magazine started in May 1958 by Fawcett Publications, the publishers of Mechanix Illustrated. The magazine was published monthly from 1959 to 1961 then bi-monthly until November 1972. Charles Tepfer was the first editor and Robert Beason was the editor for rest of the magazine's run. The headquarters was in Greenwich, Connecticut.
A transistor is a semiconductor device with at least three terminals for connection to an electric circuit. In the common case, the third terminal controls the flow of current between the other two terminals. This can be used for amplification, as in the case of a radio receiver, or for rapid switching, as in the case of digital circuits. The transistor replaced the vacuum-tube triode, also called a (thermionic) valve, which was much larger in size and used significantly more power to operate. The first transistor was successfully demonstrated on December 23, 1947, at Bell Laboratories in Murray Hill, New Jersey. Bell Labs was the research arm of American Telephone and Telegraph (AT&T). The three individuals credited with the invention of the transistor were William Shockley, John Bardeen and Walter Brattain. The introduction of the transistor is often considered one of the most important inventions in history.
The first hearing aid was created in the 17th century. The movement toward modern hearing aids began with the creation of the telephone, and the first electric hearing aid was created in 1898. By the late 20th century, the digital hearing aid was distributed to the public commercially. Some of the first hearing aids were external hearing aids. External hearing aids direct sounds in front of the ear and block all other noises. The apparatus would fit behind or in the ear.
Norman B. Krim (1913–2011) was an American electronics engineer and engineering executive. His drive to create a transistor product for the electronics experimenter-hobbyist market contributed to paving the path for a generation of American electronics engineers and technicians during the Space Race between the United States and the Soviet Union.
This article details the history of electronics engineering. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon".
The 2N107 is an early germanium alloy junction PNP transistor developed by General Electric (GE) in 1955, to become GE's entry into the electronic hobbyist market successfully started with the CK722 transistor. Like the CK722, it enjoyed a long-standing popularity. General Electric decided to designate it with a JEDEC 2N- series identification. This is unusual for a hobby device. Soon after, other manufacturers got involved in the hobby business like Sylvania, Tung-Sol and RCA.
In electronics, power amplifier classes are letter symbols applied to different power amplifier types. The class gives a broad indication of an amplifier's characteristics and performance. The first three classes are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a signal waveform applied to the input. This metric is known as conduction angle (θ). A class A amplifier is conducting through all the period of the signal (θ=360°); Class B only for one-half the input period (θ=180°), class C for much less than half the input period (θ<180°). Class D amplifiers operate their output device in a switching manner; the fraction of the time that the device is conducting may be adjusted so a pulse-width modulation output can be obtained from the stage.
