Electronics is that branch of science and technology which makes use of the controlled motion
of electrons
through different media and vacuum. The ability to control electron flow is
usually applied to information handling or device control. Electronics is
distinct from electrical
science and technology, which deals with the generation, distribution, control
and application of electrical power. This distinction started around 1906 with
the invention by Lee De
Forest of the triode, which made
electrical amplification possible
with a non-mechanical device. Until 1950 this field was called "radio
technology" because its principal application was the design and theory of radio
transmitters, receivers and vacuum tubes.
Most electronic devices today use semiconductor components to perform electron
control. The study of semiconductor devices and related technology is considered
a branch of physics, whereas the
design and construction of electronic circuits to solve practical
problems come under electronics engineering. This article
focuses on engineering aspects
of electronics.
An electronic component is any physical entity in an electronic system used to
affect the electrons or their associated fields in a desired manner consistent
with the intended function of the electronic system. Components are generally
intended to be connected together, usually by being soldered to a printed circuit
board (PCB), to create an electronic circuit with a particular function (for
example an amplifier, radio receiver, or oscillator). Components may be packaged
singly or in more complex groups as integrated
circuits. Some common electronic components are capacitors, resistors, diodes, transistors, etc. Components are often categorized
as active (e.g. transistors and thyristors) or passive (e.g. resistors and
capacitors).
Most analog
electronic appliances, such as radio
receivers, are constructed from combinations of a few types of basic circuits.
Analog circuits use a continuous range of voltage as opposed to discrete levels
as in digital circuits.
The number of different analog circuits so far devised is huge, especially
because a 'circuit' can be defined as anything from a single component, to
systems containing thousands of components.
Analog circuits are sometimes called linear circuits although many non-linear effects
are used in analog circuits such as mixers, modulators, etc. Good examples of
analog circuits include vacuum tube and transistor amplifiers, operational
amplifiers and oscillators.
One rarely finds modern circuits that are entirely analog. These days analog
circuitry may use digital or even microprocessor techniques to improve
performance. This type of circuit is usually called "mixed signal" rather than
analog or digital.
Sometimes it may be difficult to differentiate between analog and digital
circuits as they have elements of both linear and non-linear operation. An
example is the comparator which takes in a continuous range of voltage but only
outputs one of two levels as in a digital circuit. Similarly, an overdriven
transistor amplifier can take on the characteristics of a controlled switch having essentially two levels of
output.
Electronics engineering, [1] also referred to as
electronic engineering[2][3] is
an engineering discipline
which uses the scientific knowledge of the behavior and effects of electrons to develop components,
devices, systems, or equipment (as in electron tubes, transistors, integrated
circuits, and printed circuit boards) that uses
electricity as part of its driving force. Both terms denote a broad engineering
field that encompasses many subfields including those that deal with power, instrumentation engineering, telecommunications, semiconductor circuit design,
and many others.[4]
The term also covers a large part of electrical engineering degree courses as
studied at most European universities. In the U.S., however, electrical
engineering encompasses all electrical disciplines including electronics. The Institute of
Electrical and Electronics Engineers is one of the most important and
influential organizations for electronics engineers.
Electronic engineering as a profession sprang from technological improvements
in the telegraph
industry in the late 1800s and the radio
and the telephone industries in
the early 1900s. People were attracted to radio by the technical fascination it
inspired, first in receiving and then in transmitting. Many who went into
broadcasting in the 1920s were only 'amateurs' in the period before World War I.[9]
The modern discipline of electronic engineering was to a large extent born
out of telephone, radio, and television equipment development and the large
amount of electronic systems development during World War II of radar, sonar,
communication systems, and advanced munitions and weapon systems. In the
interwar years, the subject was known as radio engineering
and it was only in the late 1950s that the term electronic engineering
started to emerge.[10]
The electronic laboratories (Bell
Labs in the United States for instance) created and subsidized by large
corporations in the industries of radio, television, and telephone equipment
began churning out a series of electronic advances. In 1948, came the transistor
and in 1960, the IC to revolutionize the electronic industry. [11][12] In the UK, the
subject of electronic engineering became distinct from electrical
engineering as a university
degree subject around 1960. Before this time, students of electronics and
related subjects like radio and telecommunications had to enroll in the electrical
engineering department of the university as no university had departments of
electronics. Electrical engineering was the nearest subject with which
electronic engineering could be aligned, although the similarities in subjects
covered (except mathematics and electromagnetism) lasted only for the first year
of the three-year course.
Consumer electronics include electronic equipment intended for
everyday use. Consumer electronics are most often used in entertainment, communications and office productivity. Some products classed as consumer
electronics include personal computers, telephones, MP3 players, audio equipment, televisions, calculators, GPS automotive navigation systems, digital cameras and
playback and recording of video media such as DVDs, VHSs or camcorders. Currently, the global
consumer electronics industry is partly dominated by American, Japanese and two majors South Korean companies. These American companies
include Microsoft, Apple Inc., Seagate, Intel, AMD, Texas Instruments, Cisco, HP, Dell, Western Digital, Xerox, Lexmark, Vizio,
Whirlpool, Motorola, Kodak, IBM, Imation, EMC Corporation,SanDisk, Bose, Kingston
Technology, Monster Cable Products, Qualcomm, Garmin. These Japanese companies include Sony, Toshiba,
Panasonic, Mitsubishi
Electric, Hitachi, Sharp, NEC, Brother Industries, Canon, Casio, Konica Minolta, Fujitsu, Olympus Corporation.These two Korean
companies are Samsung and LG.
The CEA (Consumer Electronics Association) estimates 2007 US Consumer
Electronics sales at 150 billion dollars.[1]
Consumer electronics are manufactured throughout the world, although there is
a particularly high concentration of research and development activity in Japan and South Korea. The latest consumer electronics are
previewed yearly at the Consumer Electronics Show in Las
Vegas, Nevada, at which many
industry pioneers speak.
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