Conversations on Electrical Engineering: Electricity - from simple to complex

A. L. Kulsky

It is possible to assert with the fullest basis that the arena of the most diverse physical processes is not only the earthly expanses, but also the stellar world and the entire infinite universe that is unimaginable in its scale. It is not surprising that the colossal number of these processes is based on the manifestation of a VERY LIMITED number of FORCE-GRAVITATIONAL, ELECTRIC, MAGNETIC, and NUCLEAR.

Gravitational forces are the most mysterious. They control the movement of galaxies, stars and planets, they also cause the attraction of all bodies on Earth to its center. But under the influence of elementary particles, atoms, molecules, small bodies, gravitational forces play a role so small that they can be completely ignored. Nuclear forces, ensuring the stability of the atomic nucleus, decrease very rapidly with distance and practically do not manifest themselves outside the atomic nucleus. But the ELECTROMAGNETIC FORCES in nature have a surprisingly wide "arena of activity."

The study and use of ELECTROMAGNETIC FORCES underlies all known electrotechnical phenomena. Which gave rise to ELECTRICAL ENGINEERING. And the development of electrical engineering gave impetus to the emergence of ELECTRONICS.

In order to visually imagine where the boundary between electrical engineering and electronics passes, it is useful to remember the following. ELECTRICAL ENGINEERING is an area of ​​science and technology that considers the laws of functioning and methods of calculating various electrical circuits.

For example, imagine chains that include light bulbs, electric motors, transformers, etc. But if the chain is able to react independently to external influence, regardless of whether it is directly electrical or even non-electric, but converted to electrical form by special conversion devices (sensors), i.e. If the electrical circuit is designed to work with an EXTERNAL signal, this is ELECTRONICS!

The external signal can be both light exposure, and thermal, as well as mechanical, chemical, biological, etc. When such a signal is electromagnetic waves, the term RADIOELECTRONICS is used.

It can be argued that the "age" of electronics is only slightly more than 100 years. All the amazing miracles that have been possible to realize due to the successes of RADIOELECTRONICS (computers, TVs, audio and video equipment, miniature movie cameras, radiotelephones, pagers, etc.) are, in fact, only the BEGINNING of electronic miracles! Radioelectronics (and the future will only confirm this) can be immeasurably greater! ...

Radio electronics can be likened to an amazing fairy-tale country, infinitely rich in a variety of miracles and mysteries. And one who once got into this country, already for anything will not want to leave it! But, as befits all fairy tales (even if they are absolutely real), in order to get to this amazing country, you need a MAGIC KEY. It is he who is able to open the doors leading to this fairy-tale world. This key, however, must still be seized.

What is he like? First of all, it is knowledge of the basic laws of electrical engineering and electronics. Understanding of the essence of the physical processes underlying these laws. Consistent and persistent study of the modern component base, design and installation methods. And of course, the manifestation of creative initiative. But even all this - EXTREMELY INSUFFICIENT! Why?

When we warm ourselves in the evening by the fire or when we put the kettle on the stove in the kitchen, we are dealing with fire. He is visible, very hot, and therefore - UNDERSTANDING! When we are dealing with an electrical circuit, at first glance, it does not carry ANY DANGER. And this is basically the case.

Correctly assembled and maintained electrical circuit - a safety sample! But we should not forget that the introduction into this chain (accidental or intentional) of foreign conductive objects is able to radically violate this blessed picture.

If the usual bonfire flares up slowly (at best it takes minutes), and its temperature, regardless of the size of the fire, is limited (just over 800 ° C), then the temperature developed in the event of an emergency in the electrical circuit instantly reaches MANY THOUSANDS of DEGREES!

The most refractory metals are transformed into steam - platinum and tungsten! Their hot sparks scatter with a high speed and are capable of inflicting severe injuries and burns. In addition, electrical circuits have another damaging effect. He is ALWAYS PRESENT in any normally functioning electrical circuit.

It's about electrical voltage. Its presence at a certain point of the chain is completely invisible! Until the moment the careless user comes into contact with him. Therefore, it is useful for future electronics enthusiasts to assimilate for the rest of their lives several rules that must be remembered always and everywhere:

1. ELECTRICITY IS A RELIABLE AND UNKNOWN FRIEND, BUT VERY TERRIBLE, DEATHLY DANGEROUS ENEMY!

2. ANY ELECTRICAL ENGINEERING WORKS ARE INCOMPATIBLE WITH FULLNESS AND NEGLIGENCE.

3. ALL ELECTRICAL WORKS WILL BE FULL ONLY WITH THE POWER SUPPLY OFF AND TURNED OUT OF THE NETWORK OF THE FORK.

4. YOU NEED TO REMEMBER THAT UNDER SOME CONDITIONS THE DANGER OF LIFE REPRESENTS THE VOLTAGE, EQUAL 12 V!

This, of course, does not mean that electronics - something extremely dangerous and inaccessible. In no case! But the concentration, concentration and attentiveness are the qualities necessary for the future of the electronics engineer. Now we can begin a detailed conversation about electricity and electronics ... We can not say exactly when people first discovered that bodies can be NAVIED.

In any case, it happened a very long time ago. This fact was documented for the first time by the philosopher from Hellas Thales of Miletus (IV century BC). According to him, weavers noticed the ability of amber to attract light objects to itself, NOT CONCERNING with them, after this amber was rubbed against the wool. Strange behavior of amber and some other substances, at first it seemed only curious curiosity. Meanwhile, the laws governing the majority of phenomena on Earth are manifested here. How does today explain the phenomenon of electrification?

According to our modern knowledge, all substances consist of atoms, which, in turn, have a complex device. In the middle of the atom there is a nucleus around which, as it is often said, ROTATING electrons.

Each of the electrons carries an ELEMENTARY negative charge. In this case, as confirmed by ALL experiments, there is no situation in which the charge of an electron can be changed in one direction or another! Another thing is the speed and energy of the electron. Here they are perfectly manageable.

Note that in reality the electrons around the atomic nucleus do NOT rotate! They seem to be present at different distances from the nucleus. And the PROBABILITY of their presence in a certain area within the atomic space is characterized by different meanings.

We add that different atoms (depending on the composition of the nucleus) have different numbers of electrons. In a neutral atom, the number of protons in the nucleus is equal to the number of neutrons. And the number of ELECTRONS is equal to the number of protons.

The electric charges of a proton and an electron are equal in magnitude and OPTICAL in sign! But their masses differ almost 1800 times. This is the ratio of the masses of the "heavy" proton and the "light" electron.

The next fundamental concept, without which it is impossible to study electrical engineering, is the laws of INTERACTION of electric charges.

First of all, we note that SINGLE electric charges always repel each other, DIFFERENT always attract. In other words, charges ALWAYS interact with each other. For hundreds of years, as the great dispute in physics continues, how is the interaction of the two charges realized?

Initially, it was believed that electric charges directly through the vacuum (vacuum) act on each other. In this case, each charge at a distance "feels" the presence of another. This point of view is known as the LONG-DAY THEORY.

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