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 ...

An article “What is a switching power supply and how does it differ from a regular analogue”, which tells about the UPS device, has already been published on the site. This topic can be supplemented with a little story about the repair. Under the acronym UPS is often referred to uninterruptible power supply. In order to avoid discrepancies, we agree that in this article it is a Switching Power Supply.

Almost all UPSs used in electronic equipment are built according to two functional schemes. According to the half-bridge scheme, as a rule, fairly powerful power supplies, for example computer ones, are carried out. According to the two-stroke scheme, power supplies for high-power UMZCH pop-up artists and welding machines are also manufactured. Anyone who has ever repaired amplifiers with a capacity of 400 or more watts knows perfectly well what weight they have. It is, of course, about UMZCH with the traditional ...

Thyristors belong to semiconductor devices of the p-n-p-n structure, and, in fact, belong to a special class of bipolar transistors, four-layer, three (or more) transition devices with alternating conductivity. The thyristor device allows it to work like a diode, that is, to pass current in only one direction. And also like a field-effect transistor, the thyristor has a control electrode. Moreover, as a diode, the thyristor has a peculiarity - without injection of minority working charge carriers through the control electrode it will not go into a conducting state, that is, it will not open.

A simplified model of the thyristor allows us to understand that the control electrode here is similar to the base of a bipolar transistor, however, there is a limitation that unlocks the thyristor ...

The British company Pavegen Systems Ltd., whose director is Lawrence Kemball-Cook, the author of the technology, successfully produces and sells unique paving tiles around the world that generate electricity thanks to pedestrians walking along it. The idea was realized by Lawrence Kemboll-Cook in 2009, when he studied at the University of Loughborough kinetic solutions for energy networks. Cambell-Cook came up with this idea for tiles while working for one very large energy company.

Since the founding of Pavegen, Lawrence began his move into the market leaders in the energy-harvesting pedestrian sector, generating interest in technology globally. A number of commercial objects at the implementation stage picked up Lawrence's idea, transforming his concept and design into real products ...

Why is the transformer humming? Have you ever thought about this? Someone will say that this is because the coils are poorly fixed between themselves or the windings oscillate, knocking on iron. Maybe the core area turned out to be less than required by the calculations, or did too many volts per turn result in winding? Does the frequency supplied correspond to this core material? Let’s understand, however.

In fact, the cause of transformer humming is initially magnetostriction. Magnetostriction is the phenomenon of changes in the size and shape of a ferromagnetic body under the influence of an alternating magnetic field. In addition to magnetostriction, noise can be caused by working oil pumps and fans of cooling systems of powerful transformers. The electrodynamic forces in the windings and the electromechanical devices that regulate the voltage under load also create noise ...

Before installing a two-tariff electricity meter, everyone wonders how profitable it will be, and whether it will be profitable at all? In fact, not everyone will experience the economic effect of installing a two-rate meter. For some, the benefit will immediately become apparent, for someone it will appear after a while. Let’s figure out how things really are with two-tariff electricity meters, and in which cases the transition is not at all advisable, and it’s more profitable to leave a single-rate meter.

Continuously, throughout the day, everywhere there is a dynamics of electricity consumption, and this applies both to apartment buildings of megacities, and to private houses. Most people sleep at night, and during the period from midnight to 5 a.m., electricity consumption is minimal. Waking up in the morning, getting ready for work, people begin to use electrical appliances ...

When designing a lighting system, after repair or construction of an office or residential premises, it is necessary to make calculations so that there is enough light. It does not matter whether conventional incandescent lamps, compact fluorescent lamps or LED lamps are used, it is required to obtain such a luminous flux as a result so that it provides comfortable conditions for a person.

If we are talking about replacing incandescent lamps with LED ones, then in principle there is no problem in choosing LED lamps for the corresponding luminous flux, there are tables for this, since the average luminous flux for typical incandescent lamps for each specific rating is known, and the luminous flux of LED lamps can also be easily recognized simply by reading the inscription on the package.But what to do if you want to get a modern lighting system based on LEDs ...

If someone still believes that there is nothing better for connecting the wires than stripping their ends with a knife, twisting them, and wrapping them with electrical tape, then he is behind the times. Today, there are already plenty of alternative devices that greatly facilitate the process of connecting wires, and at the same time are quite reliable. Times of twisting will soon sink into oblivion, for they are replaced by a variety of terminals.

Why are the terminals good? How, for example, to connect an aluminum wire with a copper wire so that the connection is reliable and durable? It is absolutely impossible to twist copper with aluminum, because then a galvanic pair is formed, and corrosion will simply destroy the connection, it does not matter what size the current will pass through the twist, it will break down sooner or later, and if the current is greater, turn on and off the devices more often, then twisting resistance will increase faster, with time heating ...

When deciding on the power supply of a newly built building, its owner is faced with numerous tasks that need to be solved by technical and organizational methods. In this case, you should initially decide on the necessary number of phases required to power electrical appliances. Usually people are satisfied with a single-phase power supply, and a certain category selects a three-phase, guided by the tasks they face. When choosing a circuit, one should take into account its effect on the wiring design and operating conditions created by different systems.

There is a hope among individual homeowners that switching to three-phase power can increase the allowed power consumption and use electricity more intensively. However, this issue must be addressed in the sales organization ...

Modern electrical equipment in its work uses numerous technological processes that proceed according to various algorithms. An employee engaged in its operation, maintenance, installation, commissioning and repair, you must have reliable information about all their features. Providing the events in graphical form with the designation of each element in a specific, standard way, greatly facilitates this process, allows you to transfer the intentions of the developers to other specialists in an understandable form.

Electrical circuits are created for electricians of all specialties, have various design features. Among the methods of their classification, the division into principal and assembly is used. Both types of circuits are interconnected. They complement each other’s information, are carried out according to uniform standards ...

Sometimes, when there is no marking on the capacitor or there is no confidence in the parameters indicated on its case, it is necessary to somehow find out the real capacity. But how to do it without special equipment?

Of course, if at hand there is a multimeter with the ability to measure capacitance or a C-meter with a suitable range of capacitance measurements, then the problem ceases to be such. But what to do if only a simple household multimeter and some kind of power supply are available, and it is necessary to measure the capacitance of the capacitor here and now? In this case, the well-known laws of physics will come to the rescue, which will allow measuring capacitance with a sufficient degree of accuracy.

Let us first consider a simple way to measure the capacitance of an electrolytic capacitor using available tools. As you know, when charging a capacitor from a constant voltage source through a resistor, there is a pattern by which the voltage across the capacitor ...

The word "transistor" is formed from two words: transfer and resistor. The first word is translated from English as "transmission", the second - "resistance." Thus, a transistor is a special kind of resistance, which is regulated by the voltage between the base and emitter (base current) of bipolar transistors, and the voltage between the gate and source of field-effect transistors.

Initially, several names were proposed for this semiconductor device: a semiconductor triode, a crystalline triode, a lotatron, but as a result, they focused on the name “transistor” proposed by John Pierce, an American engineer and science fiction writer, friend of William Shockley. To begin with, we will plunge a little into history, then we will consider some types of transistors from the electronic components that are common on the market today. William Shockley, Walter Brattain and John Bardin ...