What does the term „electronics“ mean?
Electronics is an engineering science which aims at using the controlled motion of electrons through various media. The possibility to control the flow of electrons is most often used for manipulating information or controlling different devices. Electronics is a branch of electrical engineering, which has a wider scope, including the generation, distribution, control and application of electricity. What is the history of electronics? The history of electronics began in the middle of the last century, when the electronic tube was invented. Until the mid-20th century, this part of engineering was called radio-engineering since its major applications using mainly electronic tubes are connected with the transmission and reception of radio signals. Today, most electronic devices use semiconductor components and are used in a wide range of practice areas. The first electronic components appeared at the beginning of the 19th century, along with the discovery of electricity and its properties, but they became widely used as late as a century later. The development of electronics in the coming decades and until today has followed two basic directions – reducing the size of the basic components (transistors, and similar devices), allowing more effective integration, larger capacities and wider application, and the growing complexity of the methods used in electronic devices (e.g. the transition from analogue to digital signal processing). As a result, electronic devices have become more sophisticated and are used in most fields of engineering and in everyday life.
Electronics and its objectives. The purpose of electronics is to create practically applicable devices. Based on a constant source of energy through passive electrical and electronic components, actively managing the flow of electrons in an electrical circuit, it is possible to transform non-electrical values to electrical and vice versa, electrical signals are controlled and amplified, the creation of electromagnetic field in space becomes possible, thereby establishing a wireless connection at large distances. Historically, there are different generations of devices, and the dimensions of their single components and the power consumption have been progressively reduced. These devices are divided into: 1. Devices based on electronic tubes. 2. Devices based on discrete semiconductors 3. Devices based on mechanisms with dimensions of the order of nanometers (nanoelectronics). 4. Devices based on relays. 5. Devices based on semiconductor integrated circuits (micro-electronics)
The main task of these devices is the transfer and processing of signals and information. Electronic component is any physical entity in an electronic system, which is intended to influence the electrons or their fields in the desired manner consistent with the function of the electronic system. In most cases, the elements are connected electromechanically by soldering onto a printed circuit board in order to create an electronic circuit with a particular function (e.g. an amplifier, a radio receiver, or a generator). The components may be separate or in a complex group such as integrated circuits. Depending on whether they process analog or digital signals, electronic circuits and respectively the devices made of them are divided into analog and digital. What are electronic signals?
The main task of electronics is processing by physical components, sometimes triggered by embedded software, of electronic signals – physical quantities considered as a carrier of information. Most often, this function is performed by electric voltage or electric current, but also by other variables, such as electric or magnetic field. Electronic signals are usually divided into three main groups according to the reporting of the signal and its use – analog, digital and power signals. In many cases it is appropriate the signals to be divided into two components – a useful signal containing the requested information, and noise. This signal is divided into analog, digital, mixed and power signal.
Analog circuits.In analogue circuits the physical quantity used for transferring information is considered continuous over time, in contrast to digital circuits, where the signal has discrete values. The possible values of the analog signal are infinitely many and form a continuous interval. This feature of analog signals impedes the storage of information and the arithmetic operations of the data, which is the main advantage of digital circuits. The main application areas of analog circuits are radio-engineering, audio and video-engineering. Examples of analog circuits are vacuum tubes and transistor amplifiers, operational amplifiers and generators.
Digital circuits. Digital signals, as opposed to analog ones, may take only a certain set of discrete values that can be encoded in integers. In the simplest case the digital signal can take only two values – 0 and 1. Digital circuits are physical realization of Boolean algebra and are the basis of modern computing. The terms „digital circuit“, „digital system“ and „logic“ are synonymous in the context of digital circuits. Digital circuits are mostly used in integrated circuits, especially microprocessors and microcontrollers, and contemporary computers are composed almost entirely of digital electronic devices. Nowadays, digital circuits increasingly displace analogue ones because they can be easily elaborated, they have higher degree of integration and more flexible usage.
Mixed-signal circuits. Mixed-signal circuits belong to integrated circuits (ICs), which contain both analog and digital circuits combined into a single semiconductor substrate or over a printed circuit board. Mixed-signal circuits are normally used for controlling analog devices with digital logic, for example for adjusting the rotations of an engine. Microelectronic engineering. Microelectronic engineering is part of electronics, which is connected with the studying and the production of miniature electronic components. The production process is based on a planar technology, it is connected with the manufacture of integrated circuits and takes place in plants that are specially constructed for this purpose, where there are special precautions against dirt and dust because the slightest speck of dust can damage the finished product. A lot of electronic components have their miniature equivalents in integrated circuits: transistors, capacitors, resistors, diodes.
Undoubtedly electronics and electronic devices are an integral part of our daily lives. 99% of XXI century people use mobile phones, computers, tablets and television every day. We live in a time of continuous technical progress. Technologies and solutions that have recently been difficult to achieve for the average person are already part of our everyday lives. It is impossible to imagine life without a refrigerator or a microwave. And the TV is an absolute necessity. From an objective point of view, home appliances serve to meet our different needs, and over the years we have witnessed a huge increase in sales.