Text a Electronics

Electronics is one of the branches of science and technology. It is different from electrical science and technology. Electrical engineering tasks are the generation, distribution, control and application of electrical power. Electronics, in its turn, uses the controlled motion of electrons through different media and vacuum. This ability has a significant importance in device control.

Today, in comparison with the first devices, most modern electronic devices have semiconductor components in the base of their construction rather than vacuum tubes and electric relays.

The study of semiconductor devices and their technology is the task of physics. The design and construction of electronic circuits are the tasks of electronic engineering. There are many different electronic components such as capacitors,resistors,diodes,transistors, amplifiers, insulators etc. These components usually have to be connected together on aprinted circuit board(PCB).

A printed circuit boardwith a great amount of electronic components is an integrated circuit (IC). There are three main advantages of ICs over discrete circuits: efficiency, low cost and performance.

The high level of flexibility and reliability of transistors have a great significance in modern microelectronics. Besides, the transistor had the potential to work faster and more reliably and to consume much less power than a vacuum tube. The integration of large numbers of tiny transistors into a single small chip will have a great advantage over the manual assembly of circuits with the use of discrete electronic components.

There are two available groups of circuits and components: analog and digital. A particular device has an analog or digital circuit or a mix of the two types.

Text b Analog and Digital Circuits

Analog circuits

Most analog electronic devices, such as radio receivers, have combinations of a few types of basic circuits.

There are a great number of different analog circuits, because 'circuits' are very different - from a single component, to systems with thousands of components.

Good examples of analog circuits are vacuum tube and transistor amplifiers, operational amplifiers and oscillators.

Modern circuits are very seldom only analog. Electronic devices usually have analog and digital circuits. In this case they are ‘mixed’ rather than analog or digital.

Digital circuits

Digital circuits are electric circuits with a number of discrete voltage levels. Digital circuits are the most common physical representation of Boolean algebraand are the basis of all digital computers.

To most engineers, the terms "digital circuit", "digital system" and "logic" are identical in the context of digital circuits. Most digital circuits have two voltage levels: "Low"(0) and "High"(1). Often "Low" will be near zero volts and "High" will be at a higher level.

Not only computers but electronic clocks, andprogrammable logic controllershavedigitalcircuits in their design.