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Electronics is the study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles in devices such as thermionic valves and semiconductors. The pure study of such devices is considered as a branch of physics, while the design and construction of electronic circuits to solve practical problems is called electronic engineering.

The main uses of electronic circuits are the controlling, processing and distribution of information, and the conversion and distribution of electromagnetic power. Both of these uses involve the creation or detection of electromagnetic fields and electric currents.

While electricity had been used for some time to transmit data over telegraphs and telephones, the development of electronics truly began in earnest with the advent of radio. Today, electronic devices perform a much wider variety of tasks.

One way of looking at an electronic system is to divide it into the following parts:

  1. Inputs - Electrical or mechanical sensors (or transducers), which take signals (in the form of temperature, pressure, etc.) from the physical world and convert them into current/voltage signals.
  2. Signal processing circuits - These consist of electronic components connected together to manipulate, interpret and transform the signals.
  3. Outputs - Actuators or other devices (also transducers) that transform current/voltage signals back into useful physical form.

Take as an example a television. Its input is a broadcast signal received by an antenna or fed in through a cable. Signal processing circuits inside the television extract the brightness, colour and sound information from this signal. The output devices are a cathode ray tube that converts electronic signals into a visible image on a screen and magnet driven audio speakers.

See also: computer engineering, electrical engineering, integrated circuit, list of electronics topics, microelectronics, optoelectronics, point-to-point construction, printed circuit board, semiconductor, transducer, wire wrap

Table of contents
1 Electronic Test Equipment
2 Interconnecting Electronic Components
3 Passive Components
4 Active Components (solid-state)
5 Active Components (thermionic)
6 Electromechanical Sensors and Actuators
7 Thermoelectric devices
8 Photoelectric devices
9 Antennae etc.
10 Analog circuits
11 Digital circuits
12 Mixed-signal circuits
13 Noise
14 Electronics Theory
15 See also
16 External links

Electronic Test Equipment

Interconnecting Electronic Components

Passive Components

Active Components (solid-state)

Active Components (thermionic)

Electromechanical Sensors and Actuators

Thermoelectric devices

Photoelectric devices

Antennae etc.

Analog circuits

analog electronic appliances, such as radio receivers, are constructed from arrays of a few types of circuits.

Digital circuits

Computers, electronic clockss, and programmable logic controllers (used to control industrial processes) are constructed of digital circuits. Digital Signal Processors are another example.

Mixed-signal circuits

Mixed-signal circuits, also known as hybrid circuits, are becoming increasingly common. Mixed circuits contain both analog and digital components.
analog to digital converterss and digital to analog converterss are the primary examples. Other examples are transmission gates and buffers.


Associated with all electronic circuits is noise. Types of noise include

Electronics Theory

See also

External links

Tutorials and Projects

Some other good sites