Why to this day in the energy industry for the transmission and distribution of electricity everywhere have frequencies of 50 and 60 Hz been selected and remain accepted? Have you ever thought about this? But this is not at all accidental. In the countries of Europe and the CIS, the standard 220-240 volts of 50 hertz is adopted, in the North American countries and in the USA - 110-120 volts of 60 Hz, and in Brazil 120, 127 and 220 volts of 60 Hz. By the way, directly in the USA in the outlet sometimes it can turn out, say, 57 or 54 Hz. Where do these numbers come from?

Let's turn to the story to understand this topic. In the second half of the 20th century, scientists from many countries of the world actively studied electricity and searched for its practical application. Thomas Edison invented his first light bulb, thereby introducing electric lighting. The first DC power plants were built. The beginning of electrification in the USA ...

In fact, all these electrical products are designed to perform a common task: the transmission of electricity from a voltage source to a consumer. They must perform their functions for a long time and reliably without creating emergency situations and malfunctions. Wires and cables work in all fields of human practice, when it is necessary to create a closed loop for the passage of electric current, to eliminate its loss through unforeseen leaks.

Due to the similarity of the issues being addressed, many ordinary people do not distinguish their differences, they belong to the same category. However, cables, wires and cords operate in different operating conditions, are used on different sections of electric current mains, and differ in purpose. Therefore, they have a different internal structure and design. On electric transmission lines, there are cases when electricity is transmitted ...

With the advent of LEDs, back in the seventies, LED ceiling lighting began to gain more and more popularity. And if earlier radio amateurs experimented with a sharp spectrum of ordinary LEDs, where the choice of color was small, now, with the advent of more advanced LEDs, softer spectra, the scope for creativity has expanded significantly.

Now LED strips and special controllers are widely available, as well as power supplies for every taste, for any required power. Today, you can smoothly adjust the brightness and color, create light scenarios. In principle, any person who is knowledgeable in technology will be able to design and install LED illumination of a suspended or suspended ceiling. Most often, they implement one of four popular options: contoured diffused illumination, directional illumination, figured backlight ...

A substance known to scientists for more than a hundred years, only today, at the beginning of the XXI century, it turned out to be very promising material for the production of cheap and effective solar cells. Perovskite, or calcium titanate, first found in the form of a mineral by the German geologist Gustav Rosa in the Ural Mountains back in 1839, and named after Count Lev Alekseevich Perovsky, a glorious statesman and collector of minerals, the hero of the Patriotic War of 1812, turned out to be the most suitable contender for the role of the alternative to silicon in the production of solar cells.

As a substance, until recently, calcium titanate was widely used only as a dielectric for multilayer ceramic capacitors. And now they are trying to apply it to build highly efficient solar panels, since it turned out that this material perfectly absorbs light ...

We all know that magnets are attracted by opposite poles and repelled by the same name.And if you take two magnets, for example, from furniture latches, and simply put them on the table so that their magnetization vectors are directed in different directions (one magnet with the north pole up, the other with the south), and try to bring the magnets closer, then it’s easy to detect, that they will be attracted, and there is nothing surprising in this.

Now let's move on. Take a few magnets from furniture latches, and make high stacks of them, which we place in a similar way. Obviously, the picture is similar. Now take a stack and a single magnet - a single magnet is attracted to the stack. But what will happen if the stack is not solid, but divided in the middle by a gasket, for example a cardboard, the thickness of a single magnet? In this case, we get additional poles ...

When designing any energy system, specially trained electrical engineers using technical manuals, tables, graphs and computer programs perform its analysis on the operation of the circuit in various modes, including. idling, rated load and emergency situations.

A special danger is the third case when a network malfunctions occur that can damage the equipment. Most often, they are associated with “metallic” shorting of the supply circuit, when electrical resistances with a dimension of a fraction of Ohm are randomly connected between different potentials of the input voltage. Such modes are called short-circuit currents or abbreviated as "short circuit". They arise in case of malfunctions in the operation of automation and protection, errors of staff, natural disasters ...

In modern society, there is a paradoxical situation where people use electricity on a massive scale, but for the most part they do not fully represent the degree of risk to their own life and health that they constantly expose themselves to. Even among electricians who have undergone professional training and constantly pass exams in accordance with safety rules to regulatory authorities, there is not always a clear and complete understanding of the dangers surrounding them of electric shock in everyday life.

For the urban population living in high-rise buildings, periodically serviced by teams of electricians and on the balance of housing organizations, general security issues are supported by the service of the chief engineer. And in the private sector, unfortunately, everything is left to chance. Owners of cottages, individual residential buildings independently solve a lot of construction issues ...

The power supply of any facility should be uninterrupted, but sudden power outages, unfortunately, are not excluded. For such important facilities as hospitals, defense industry facilities, and for many others, accidents at power plants or in power supply networks are in great trouble, for this reason much attention has always been paid and is being paid to the design and construction of backup power supply systems.

Often uninterrupted power supply is ensured by the fact that the consumer has two sources independent from each other, the main and the backup. The main source is the substation line, and the backup is another line that receives power from another power station, or from an autonomous power source, for example, from an industrial generator for liquid fuel or from a battery of batteries, as is often the case ...