physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter / From Wikipedia, the free encyclopedia

Electronics is the study of electricity (the flow of electrons) and how to use that to build things like computers. It uses circuits that are made with parts called components and connecting wires to do useful things. The science behind Electronics comes from the study of physics and gets applied in real-life ways through the field of electrical engineering.

A printed circuit board.

Many people can name several simple electronic components, such as transistors, fuses, circuit breakers, batteries, motors, transformers, LEDs and bulbs, but as the number of components starts to increase, it often helps to think in terms of smaller systems or blocks, which can be connected together to do something useful.

One way of looking at an electronic system is to separate it into three parts:

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

A television set, for example, has as its input a broadcast signal received from an antenna, or for cable television, a cable.

Signal processing circuits inside the television set use the brightness, colour, and sound information contained in the received signal to control the television set's output devices. The display output device may be a cathode ray tube (CRT) or a plasma or liquid crystal display screen. The audio output device might be a magnetically driven audio speaker. The display output devices convert the signal processing circuits' brightness and colour information into the visible image displayed on a screen. The audio output device converts the processed sound information into sounds that can be heard by listeners.

Analysis of a circuit/network involves knowing the input and the signal processing circuit, and finding out the output. Knowing the input and output and finding out or designing the signal processing part is called synthesis.