Selection and comparison of various backup power sources with specific parameters, consumer capabilities and prices.

Unfortunately, the solution to the problem of sudden blackouts (electricity) in our country is completely transferred to the shoulders of homeowners. Yes, emergency services still exist, but the deadline for fulfilling the application for the restoration of electricity supply is practically unlimited by anyone and can range from hours to weeks. If, God forbid, the substation transformer burned out in your collective farm, then you can assume that the end of the world has come.

The only good news is that in the courtyard of the 21st century and with the general decline of the Russian economy, energy sources appear in stores that can help in this situation. If you do not have alternative energy sources in mind: a wind generator, a solar battery, a compact hydroelectric station, which were discussed in previous ...

What is a time relay? The algorithm of the time relay is quite simple, but sometimes it can cause admiration. If we recall the old washing machines, which were affectionately called the "bucket with a motor", then the action of the time relay was very clear: they turned the knob a few ticks, something started to tick inside, and the engine started.

As soon as the handle pointer reached zero scale division, the wash ended. Later, cars with two timers appeared - washing and spinning. In such machines, the time relays were made in the form of a metal cylinder, in which the clock mechanism was hidden, and outside there were only electrical contacts and a control knob.

Modern washing machines - automatic machines (with electronic control) also have a time relay, and it became impossible to make it out as a separate element or part on the control board. All time delays are obtained ...

In order to correctly understand the various power supply schemes of residential buildings, you need to know about three categories of ensuring the reliability of power supply of electrical installations. The simplest category is the third. It provides for the power supply of a residential building from a transformer substation via a single electric cable. In this case, in the event of an emergency, the break in the power supply of the house should be less than 1 day.

In the second category of reliability of power supply, the residential building is powered by two cables connected to different transformers. In this case, when a single cable or transformer fails, the power supply of the house for the duration of the troubleshooting is carried out through one cable. A break in the power supply is allowed for the time required by the on-duty electrical personnel to connect the loads of the whole house ...

Heat-shrinkable materials are widely used in many industries and primarily in electrical engineering, due to a sufficiently high electrical resistance. In addition to electrical engineering, they are also used in many other industries. This is a new promising and easy to use material with very good performance properties. First of all, it is a high electrical resistance, resistance to low temperatures and aggressive environments: acids, alkalis and oil products.

The most well-known and common heat-shrinkable tubes, or as they are called heat shrink. The main property of the tubes is the ability to compress under the influence of high temperature.Moreover, compression occurs only in the transverse direction (the diameter of the tube decreases), but there is no noticeable increase in length. Such tube properties are obtained ...

The article considers the main criteria for choosing a cable section, gives examples of calculations.

In the markets, you can often see hand-written signs indicating which cable the customer needs to purchase depending on the expected load current. Do not believe these signs, as they mislead you. The cable cross-section is selected not only by operating current, but also by several parameters.

First of all, it must be borne in mind that when using a cable at the limit of its capabilities, the cable cores heat up several tens of degrees. The current values ​​shown in the figure assume heating of the cable cores to 65 degrees at an ambient temperature of 25 degrees. If several cables are laid in one pipe or tray, then due to their mutual heating (each cable heats all other cables), the maximum allowable current is reduced by 10 - 30 percent. Also, the maximum possible current is reduced ...

Many, making repairs, do not even think about the need to order a project for the electrical network of their apartment. And in vain. If there is a power grid project made by a qualified designer, the likelihood of making mistakes in building a network is significantly reduced.

A qualified electrician can often make a good electrical network for a small apartment by selecting the required cables for the permissible current, but in the future the lack of a project often leads to big trouble. Problems appear when a fault occurs in the wiring. Finding a malfunction in a furniture-laden apartment in the absence of a project can be so difficult that you first have to move all the furniture in search of the missing contact, and then hammer the walls in a well-repaired room. If you are repairing a large apartment with long electric lines ...

Until recently, two types of electric underfloor heating could be found on sale: based on heating cables and heating mats. They did not have differences in the principle of operation, and the choice between them depended only on the features of the room in which floor heating is required.

A few years ago, a brand new infrared film-based warm floor appeared on the market. Manufacturers unanimously declare the numerous advantages of this type of electric underfloor heating. Many people who carry out repairs in their apartments are interested in the question: “What kind of electric underfloor heating to lay?”.

The main argument of sellers in favor of heating films is the beneficial effect of infrared radiation on the human body. Indeed, medical research has established the healing properties of infrared radiation. It is used in physiotherapy to treat many diseases ...

One of the significant inventions of the XX century is considered to be the invention of the transistor, which came to replace electronic tubes.

For a long time, lamps were the only active component of all electronic devices, although they had many shortcomings. First of all, it is a large power consumption, large dimensions, short life and low mechanical strength. These shortcomings were felt more and more sharply with the improvement and sophistication of electronic equipment.

A revolutionary revolution in radio engineering took place when outdated lamps were replaced by semiconductor amplifying devices - transistors, devoid of all the mentioned disadvantages. The first operable transistor was born in 1947, thanks to the efforts of employees of the American company Bell Telephone Laboratories. Their names are now known throughout the world. These are scientists - physicists W. Shockley, D. Bardin and W. Brighten ...