Continuing the study of electrical processes, a circuit was built on the disk, according to which a smooth transition was made from the general concepts of electrical engineering to more specific and detailed ones. In the second part of the course, the main emphasis is placed on a deep study of electronics, showing the operation and arrangement of semiconductor devices, as well as their use in frequently encountered electronic circuits.

The science of electronics began to take shape at the beginning of the century, when the first electronic devices were created. Compared to other sciences, such as physics and chemistry, which have accumulated knowledge for hundreds of years, electronics is quite young. However, the practical results of research in this area have brought about a technological revolution that has revolutionized the world ...

Many of us from childhood remember that a bare tattered wire that fell to the ground is very dangerous. I remember various passions-muzzles about wet weather and about unfortunate victims who did not even have “happiness” to touch the metal, which was energized and caused their injury. All in all, they managed to pass in dangerously close to the damaged line - and this was more than enough.

But what kind of phenomenon is it, thanks to which a wire that lies “innocently” lying to one side becomes a deadly threat? Everyone knows that an electric shock to a person can only be caused by an electric current passing through his body. And electric current needs a clear path. You need at least two points of application on the body of someone who is unlucky: one of them is the phase from where the current can come, and the second is zero, where it can freely go ...

From earlier articles posted on bgv.electricianexp.com, you can see that as soon as the question relates to the methods of connecting the wires, disputes immediately arise over which of the connection options is better and more reliable. The best quality contact connection will always be one that provides the lowest transition contact resistance for as long as possible.

Contact connections in large numbers are included in all electrical circuits and devices and are their very important elements. Since the trouble-free operation of electrical equipment and wiring depends to the greatest extent on the state of electrical contacts, in this article, let’s take a look at what “transition contact resistance” is and what factors depend on it. Lean wherein will be on theory of electrical apparatus ...

How badly will a person be injured by electric shock when they come under voltage? It depends on many factors, such as the type of current in the network, the path of the current passing through the victim’s body, the electrical resistance of the body, and, of course, the touch voltage.

Here about the last factor and I would like to talk in more detail. At one time I had to listen to lectures on electrical safety from a professor at a local university. From year to year I had to see how the professor performs the same trick in front of an audience.

The trick was this: the professor, a respected man of advanced years, openly hooligans, bending a metal paper clip and shoving it with his bare hands alternately in both sockets of a 220-volt electrical outlet. There were no health consequences for the professor ...

Reed switches have a number of mechanical and electrical parameters that characterize their properties.These parameters can be divided into two large groups: mechanical and electrical.

The mechanical parameters include the magnetomotive actuation force. This parameter shows at what value of the magnetic field the contact is released and released. In technical documentation, this is referred to as the magnetomotive actuation force (denoted by Vav) and the magnetomotive releasing force (denoted by Vsp).

Important parameters of the reed switch, in some cases the main ones, is the speed of its operation and release. These parameters are usually measured in milliseconds and are designated respectively as tav and totp, which generally characterize the speed of the reed switch ...

Switching devices or just contacts are very widely used in various electrical and radio equipment. In order to improve operational properties, first of all, the service life and reliability of the connection, magnetically controlled sealed contacts called reed switches were developed.

The first samples of such contacts appeared in the 30s of the last century, and the first magnetically controlled contact was invented in 1922 in St. Petersburg by Professor V. Kovalenkov, for which he was issued the USSR copyright certificate No. 466.

In fact, this was the very first magnetically controlled contact, only without a sealing shell. A similar contact was first placed in the sealing shell by an American engineer W.B. Ellwood only in 1936 ...

The article discusses various types of electric motors, their advantages and disadvantages, development prospects.

Electric motors, at present, are an indispensable component of any production. In utilities and in everyday life, they are also used very often. For example, these are fans, air conditioners, pumps for heating, etc. Therefore, a modern electrician needs to be well versed in the types and design of these units.

DC motors. This type of motor was previously used very widely, but at present it is almost completely replaced by asynchronous electric motors, due to the comparative cheapness of the application of the latter. A new direction in the development of DC motors are DC valve motors with a permanent magnet armature ...

Each of us, of course, had to turn on the light bulb, repair the burned cord on the iron, and tighten the contacts in the outlet. Moreover, it is not necessary to have a special electrical engineering education. About the same as it is not necessary to know to the smallest detail the device of an internal combustion engine in order to become a car enthusiast.

It is exactly the same with electricity: it is completely optional to invite an electrician from the ZhKO to replace an unusable switch or socket. But at the same time, one must know the danger of electricity, and what rules must be observed so as not to lose forever the desire for such work. First you should get acquainted with the rules of electrical safety. So why is electricity dangerous to the human body? ...