Electronics is the study of the flow of charge through various materials and devices such as
semiconductors,
resistors,
inductors,
capacitors, nano-structures and
vacuum tubes. Although considered to be a theoretical branch of
physics, the design and construction of
electronic circuits to solve practical problems is an essential technique in the fields of
electronic engineering and
computer engineering.
The study of new semiconductor devices and surrounding technology is sometimes considered a branch of
physics. This article focuses on
engineering aspects of electronics.
Electronic systems are used to perform a wide variety of tasks. The main uses of electronic circuits are:
- The controlling and processing of data.
- The conversion to/from and distribution of electric power.
Both these applications involve the creation and/or detection of
electromagnetic fields and
electric currents. While
electrical energy had been used for some time prior to the late 19th century to transmit data over
telegraph and
telephone lines, development in electronics grew exponentially after the advent of
radio.
One way of looking at an electronic system is to divide it into 3 parts:
- Signal processors – These circuits serve to manipulate, interpret and transform inputted signals in order to make them useful for a desired application. Recently, complex signal processing has been accomplished with the use of Digital Signal Processors.
- Outputs – Actuators or other devices (such as transducers) that transform current/voltage signals back into useful physical form (e.g., by accomplishing a physical task such as rotating an electric motor).
For example, a
television set contains these 3 parts. The television's input transforms a broadcast signal (received by an antenna or fed in through a cable) into a current/voltage signal that can be used by the device. Signal processing circuits inside the television extract information from this signal that dictates
brightness,
colour and
sound level. Output devices then convert this information back into physical form. A
cathode ray tube transforms electronic signals into a visible
image on the screen. Magnet-driven
speakers convert signals into audible sound.
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http://en.wikipedia.org/wiki/Electronics