Electronics

The electronic is a branch of the physics applied which treats devices whose operation depends on the circulation of electrons.

The “electronic” term also indicates what is in connection with the electron.

One generally dates the beginnings from electronics with the invention of the electron Tube in 1904.

Because of the success of the apparatuses functioning thanks to electronics and their impact on the everyday life, the general public amalgamates often electronic with Cybernétique (science of the Automatisme S), as well as with Informatique.

Definition

Electronics is a Science Technique or science of the Engineer, which studies and conceives the structures carrying out of the treatments of electrical signals, i.e. of current or electric tensions , carrying information or energy.

In this definition the notion of information is considered in the broadest direction: it indicates any size (Physique, the such Température or the Speed, or abstracted, a such its, a Image, a code) which can evolve/move in real-time according to a unknown Loi in advance.

Like all the automatisms, the well conceived electronic systems comprise two parts:

  • one, operative, manages the signals of power carrying energy (high tension currents);
  • the other, informational, manages the signals carrying information (low currents).

In the traditional electronic systems processing the data, this one is coded by the tensions and the electric currents. The applications of electronics can be subdivided according to the finality of the action which they aim: the data processing strictly speaking or orders it. The first include the fields like the Informatique, the Télécommunications, the measurement S (taking away and storage of the Information), etc

The applications of order have as an aim the control of the operation of a natural system or technogene. A control generally implies a measurement of the controlled parameter, its comparison with the model and, in the event of error, the generation of an instruction of correction. Thus, a control can be seen like a succession of operations of treatment of the signal: this returns to the general standard given higher.

Disciplines of electronics

Electronics is a family of disciplines being distinguished according to the type of signal treaty, the family of application or the hierarchical level which the element studied in the total system occupies.

Types of treated signals

Analogical informational signal

See also: electronic analogical

The discipline being interested in the treatment of the analogical signals, i.e. evolving/moving in a continuous way in time and being able to take values belonging to a space of values continuous (or continuous by intervals) is called “analogical electronics”. The majority of the physical systems are it, because the physical sizes generally evolve/move in a continuous way (for example, the temperature).

Numerical informational signal

See also: electronic numerical

By opposition, numerical electronics is interested in the treatment of the signals whose space of values is discrete. Thus the number of values which these signals can take is limited. Those are coded by binary Nombre S . In the simplest case, a numeric signal can take only two values: 1 and 0. Numerical electronics is used in particular in the systems containing a Microprocesseur or a Microcontrôleur. For example, a Ordinateur is an apparatus made up in major part by numerical electronics.

At the present time numerical electronics tends more and more to replace analogical electronics, so as to facilitate the development of the circuits and to bring a better integration and a greater flexibility in use. In the general public applications, this evolution is particularly remarkable in the fields of the audio and the video (Caméscope S, Télévision) where analogical electronics was for a long time widespread - the case of photography is separately a little insofar as the acquisition of the signal was not electronic but chemical before. On the other hand, it should not be forgotten that as the discrete values do not exist physically, of the phenomena of analogical electronics can occur in the digital circuits, in particular in the high frequencies. Moreover certain functions as measurement or amplification is intrinsically analogical and will be able to never become numerical. All the sensors are in general analogical.

The numeric signals being also discrete signals in time, one uses in general an oscillator with quartz (clock) so as to synchronize the various parts of one circuit between them. One calls the circuits having a clock (or more) synchronous circuits. The Fréquence (or frequency of clock), expressed in Hertz (Hz) of a digital circuit represents the number of possible changes of state of a value a second. However, it is completely possible to work in an asynchronous way of a clock if the operation of the circuit is organized so that its various parts are synchronized between they by exchanges of signals of control (one speaks about handshaking ). One then speaks about electronic asynchronous.

Mixed electronics

One also speaks about mixed electronics, it is then about a system in which coexist the numeric signals and analogical. The modules particular to this discipline are the Analog-to-digital Converter (EDGE) and the Digital-to-analog converter (CNA). They make it possible to transform an analogical signal into numeric signal and vice versa, by thus making an interface between the purely analogical modules (like the sensors) and purely numerical.

For example, a thermometer with digital display takes the temperature (which is an analogical size), measurement its value, codes it in a numerical sequence and then the poster on a screen. Thus, the first two operations are carried out by modules of analogical electronics, the third requires an analog-to-digital conversion and the last changing of a digital processing.

Signal of power

See also: electronic of power

The electronics of power is the whole of the techniques which are interested in the energy contained in the electrical signals, contrary to the other electronic disciplines, which they are interested mainly in the Information contained in these signals. The range of power treated in electronics of power varies some micro Watt with several Méga Watts.

The electronics of power rests on devices making it possible to change the shape of electrical energy, (converters) and of the devices Transducteur S (most usually of the Turbine S and the electrical motors). The electronics of power has like field of application the electrotechnical domestic and industrial where it replaces the old solutions electromechanical S.

Hierarchy of the object of study

In a way independent of the application, certain disciplines of electronics are defined according to the place which the object of the study in the hierarchy of an electronic system occupies.

Physics of the components

At the level low a Composant, or an electronic device is located. The branch being interested in the design and the study of an elementary electronics component is called “physics of the components”. It is related with the technological know-how, which gathers the whole of knowledge and necessary tools to him to manufacture a component. One speaks thus about the “technology of electronics”. The fields of the technology and the physics of the electronics components call primarily upon competences in fundamental sciences, such as the Physics chemical proceeded and solid state . Even if these activities are vital for electronics, they have to see little with electronics as a genius of the Treatment of the signal. One should rather regard them as a main door of the world of fundamental physics towards the science applied which is electronics. The basic components of electronics are the Transistor S, the resistance S, the condensing S, the Diode S, etc

Electronic engineering

An electronic circuit is the main object of study of the science of electronics. An electronic circuit is a system including several associated electronics components. The word circuit comes owing to the fact that the treatment is carried out thanks to electric currents circulating in the inter-connected components. The branch studying the properties of the electronic circuits is called “theory of the circuits”. The discipline which studies methodology making it possible to fulfill a particular function of treatment containing a circuit calls “design of the electronic circuits”. The modern electronic systems comprise hundreds of elementary million components. For this reason the genius of the electronic circuits is interested only in the realization of functions (or modules) relatively simple, requiring a few tens of components.

Cut electronic circuits

The preceding classification is recut with a classification according to the size of the electronic circuits considered.

Electronics of the vacuum tubes

As its name indicates it, she resorts to vacuum tubes , or electron tubes like elementary active components (diodes with vacuum, triodes, tetrodes, pentodes…). She hardly remains today than in the shape of the cathode tubes of and certain the component television receivers of radio operator transmitters of very strong power, and these tubes are besides them also in the process of disappearance. Remain however the technology of the vacuum tubes used in audio, in the amplifiers guitar in particular.

The vacuum tubes, in their simplest configuration (diode), are composed of two electrodes, are called cathode and anode installed in a tube of glass where the vacuum was created. Cathode is heated by a heater, which makes it possible to create a “cloud” of electrons near cathode. When the electronic circuit to which the tube is connected creates a positive potential with the anode compared to cathode, it occurs an electric current (electrons) between cathode and the anode (called cathodic current). It is possible to incorporate metal grids between cathode and the anode. Various potentials applied to these grids will cause to control the cathodic current. The tubes equipped with a grid are called three-electrode (three electrodes).

The design of the vacuum tubes makes it extremely tolerant to the overloads. This characteristic positions still today the vacuum tube like an important candidate for the extreme applications, such as the radio operator transmitters (MY and MF) of power and the tubes of emission to x-rays.

Lastly, let us note that the light (only one photon) directed towards cathode is sufficient to generate a cathodic current, and this, without same using heater. The “dynodes” use this principle cascades about it to detect the photons in certain applications of medical imagery.

Individual electronics

She resorts to individual or “discrete” elementary components (in opposition to integrated) generally assembled on electronic charts . This type of electronic design hardly is used than for breadboard constructions or within the framework of the entertainment electronics, because it was supplanted by the micro-electronics. On a current electronic chart, although the integrated circuits achieve the principal functions, one however always finds the components discrete necessary to their implementation (resistances and condensers primarily).

Micro-electronic

This term was born from the process of the miniaturization of the elementary electronics components. This miniaturization started in the the Fifties with the birth of the Semi-conducteur S, it reached an almost extreme phase today. Indeed, for six decades the size of the elementary components has not ceased decreasing, to reach dimensions about a few tens of Nanomètre S. This progress became possible thanks to the projections in the processes of treatment of the semiconductor materials, in particular of the Silicium, which made it possible to carry out several million elementary components on a surface of a few square meters. Thus, the micro-electronics is interested in the electronic systems using of the components of micrometric and nanometric size. The integrated “electronic” expression is a synonym of this term: it evokes a whole of components “integrated” on only one chip of semiconductor, commonly called integrated circuit.

Nano-electronics and molecular electronics

In addition, while speaking about the systems of modern electronics, the “micro” prefix starts to be obsolete, insofar as one sees appearing components whose size is measured in Nanomètre S and sometimes comparable with that of the Molécule S. nano-electronics, the Nanotechnologie S and molecular electronics are thus evoked. Recent technical projections even make it possible to consider the design of components based on the property of the electron S and of their Spin: the Spintronique.

Microsystems

For a few years, with progress in the microphone and nano-technologies, one has observed a fusion of the systems belonging to various technical fields (mechanical, thermal, optical…) around the circuits and electronic systems. These fusions are often called “systems with signal processing multi-field”, or “systems multi-fields”. At the origin of this progress are the processes of Usinage silicon very advanced, which make it possible to carry out three-dimensional structures on the same silicon crystals with the electronic circuits. This proximity offers an interpenetration of the treatments traditionally proceeding in different fields, and a coexistence of the signals of various physical nature (thermics, mechanics, optics…) in the same system.

electromechanical Microsystem

Thus, in the Années 1990 the true technological revolution took place with the appearance of the electromechanical Microsystems (in English MEMS like MicroElectroMechanical Systems). They are traditional mechanisms such as resonators, beams, micro engines, etc realized on silicon on a micrometric scale. These various machine elements are put moving (actuated) thanks to the forces generated by Transducteur S electromechanics. Those are fed by tensions produced with neighbouring electronic circuits. The electromechanical transducers play then the part of the Interface between the fields mechanics and electric. The electrostatic or capacitive transducers are generally used there, although one can meet electromechanical interfaces based on magnetic and thermomechanical phenomena.

History

Since the beginning of the 19 {{E}} century, progressively of the discoveries of the possibilities of the electricity, the electronic Component S and applications were born, (sometimes without possibility of immediate application or manufacture Industrie it, these discoveries will be used only later).

Without electronics and obviously the supply electricity essential to its operation, the life in our modern company would be quite different.

See also the electronics components in general.

Theoretical base

A component is an element making it possible to build a Electrical circuit where a Electric current circulates.

Passive components

  • a component is known as " passif" when he obeys the Loi of Ohm generalized, i.e. when the tension U at the boundaries of the component varies linearly with the intensity I of the current which circulates there, or which:

U = R \ cdot I in continuous mode (R = resistance)
U = Z \ cdot I in any mode (Z = impedance)
  • They do not have as a function to modify the nature of the electric current which crosses them.
  • the component known as passive (resistance, condensing, winds, Connecteur) saw their techniques manufacture to evolve/move very appreciably, following close the technological improvements.
  • On the other hand their basic principles were never given in question.

Active components

  • a component is known as " actif" when the purpose of this one is to modify the currents which crosses it. For example, the Diode S, Three-electrode S, the Transistor S, the Thyristor S, etc are active components.

  • At the beginning, the active components included/understood only electron tubes.
  • Since with the use of the Semiconductor S and inter alia the invention of the Transistor in 1948, consumer electronics invaded our Maison S, our Automobile S, the Téléphone and all the Machine S of the everyday life.
  • the integrated circuits, evolution integrated of the transistor, gain day in day in Densité. Those supported the explosion of modern electronics: Analogical and especially Numerical.
  • the miniaturization of the applications sees the emergence of electronics low power, discipline which makes it possible to create portable electronic devices, at the beginning the watches (since 1967), then medical apparatuses (auditive assistances) and maintaining the computers and cellphones.
  • the era of the microcomputers could see the day thanks to the projections of the numerical electronic .
  • During the two last decades of the 20th century, electronics was associated with the possibilities of the Lumière and the Optique (Laser and Fiberoptic): the Opto-electronic , to manufacture electronic new generations of machines.

See too

Internal bonds

  • Trades of electronics

    • Bep of the trades of electronics
    • Electronics specialist
    • Electronics engineer
    • Technician in electronic manufacture
    • Technician of research department in electronics
    • High-level technicien of applications in electronics

External bonds

  • Treated of electronics by F6CRP
  • Resources electronic engineering
  • Interactive Power Electronics Online race

Simple: Electronics

Random links:Intermediate Common Format | ACE Vita Club (Kinshasa) | Bernt Haas | Knightsbridge | A dispenser of justice in the city