While the light is on, and all home electrical appliances are working, everything is fine, but as soon as the machine is knocked out, you have to find and fix the malfunction. Well, if the owner of the home is an experienced electrician, then he probably has a phase indicator in the shape of a screwdriver in his home tool, or certainly a multimeter. But what if there is neither one nor the other in the household? Is there any other way to safely detect a malfunction in an electrical circuit?

As a rule, in such cases, some home craftsmen resort to the help of the so-called warning lamp, which, incidentally, is very unsafe and generally prohibited by safety regulations. For this reason, a phase indicator is still better to have on the farm. But why is the warning lamp prohibited? Let's try to understand this in detail. Incandescent lamps, which are usually used as a control lamphave a bad habit of failing at the most unexpected moment ...

From the point of view of the electromagnetic process occurring in it, any element or section of an electric circuit is primarily characterized by the ability to conduct current or impede the passage of current. This property of the circuit elements is evaluated by their electrical conductivity or magnitude, reverse conductivity - electrical resistance.

Most electrical devices consist of conductive parts made of metal conductors, usually equipped with an insulating coating or sheath. The electrical resistance of a conductor depends on its geometric dimensions and material properties. The resistivity and conductivity take into account the properties of the material of the conductor and give the values ​​of resistance and conductivity of the conductor with a length of 1 m and a cross-sectional area of ​​1 mm². By the value of resistivity ρ, all materials can be divided ...

Any private house or apartment in a multi-storey building must have its own electrical panel. In the classic form, the electrical panel looks like a metal box with a door, and various devices and a meter are installed inside (or meters, if the panel refers, for example, to several apartments located on the same platform at the entrance).

For an absolutely uninitiated person, the devices located behind the door are something transcendental, it is not clear why they are standing there. Meanwhile, an electrical panel is a necessary, but unsafe thing, so it’s better not to climb into it without the need and qualifications. The distribution and accounting board (as it is correctly called) is initially designed and installed by specially trained craftsmen (electrical engineers) during the design and electrical installation works. They design the wiring, choose the future location for the installation of the shield ...

Different parts of electrical appliances, as a rule, need a different voltage supply. In order to ensure this, transformers with several secondary windings producing different voltages are used in the power supply units of these devices, or several separate transformers are used, each of which provides its own specific voltage.

So, for example, in old TVs (with CRT tubes), 5-7 volts for powering transistors, microcircuits, or lamps were obtained from one transformer, and several kilovolts for powering the picture tube anode - from another - a high-voltage, so-called horizontal transformer.This transformer further fed the voltage multiplier, which several times increased the high voltage received from the secondary winding of the line generator. In the old days, when pulsed semiconductor technology was not ...

Depending on the purpose, on the expected operating modes and conditions, on the type of power supply, etc., all electric motors can be classified according to several parameters: by the principle of obtaining the operating moment, by the method of operation, by the nature of the supply current, by the method of phase control, by type of excitation, etc. Let us consider the classification of electric motors in more detail.

Torque in electric motors can be obtained in one of two ways: by the principle of magnetic hysteresis or purely magnetoelectric. The hysteresis motor receives torque through the hysteresis during magnetization reversal of the magnetically solid rotor, while the magnetoelectric motor torque is the result of the interaction of the explicit magnetic poles of the rotor and stator. Today, magnetoelectric motors rightfully constitute the lion's share of the total abundance of electric motors ...

In the age of integrated circuits and smartphones, chips and supercomputers, it would seem ridiculous to think about electro-vacuum devices, such as electronic radio tubes. Everywhere they were replaced by transistors, and their place in the museum has long been theirs. Of course, there is some truth in these statements, nowadays the lamps are really not as widely used as before, nevertheless, to this day there remain areas in which they are indispensable and very popular.

Indeed, the principle of operation of the kenotron, triode, and other electrovacuum devices is not so complicated. Between the electrodes inside the evacuated housing, an electron flow is initiated. The intensity and direction of this electron flow can be controlled using an electric or magnetic field. Electric current in a vacuum is striking in its properties: a lamp can generate oscillations in the widest frequency range, from sound to radio waves ...

When installing the lighting system in the entrance, it would be nice to make it as economical and automated as possible so that the light turns on only when it is really necessary, and does not burn around the clock, as was the custom in the nineties - until the light is turned off or smash.

In fact, such a system can be useful not only for entrances, but also for various utility rooms, parking lots, corridors, etc. Infrared motion sensors are very suitable here, able to respond to objects moving in their area of ​​operation. The primary task is to correctly install and configure such a sensor, and this will be discussed later. Modern models of infrared motion sensors allow the adjustment of three parameters: the threshold of illumination, indicating the onset of darkness, when the motion sensor begins to work ...

The terms "capacitive load" and "inductive load", as applied to alternating current circuits, imply a certain nature of the interaction of the consumer with an alternating voltage source.

Roughly this can be illustrated by the following example: connecting a fully discharged capacitor to the outlet, at the first moment of time we will observe an almost short circuit, while connecting the inductor to the same outlet, at the first moment of time, the current through such a load will be almost zero.This is because the coil and capacitor interact with alternating current in fundamentally different ways, which is the key difference between inductive and capacitive loads. Speaking of capacitive load, they mean that it behaves in an AC circuit like a capacitor.This means that a sinusoidal alternating current will periodically recharge ... 

Batch switches are used for switching electrical circuits. At the same time, they can be used both in direct and alternating current circuits with voltage of 220, 380 V. However, people often confuse and call circuit breakers “packets” in the old fashion, which is fundamentally wrong. Therefore, let's understand what is and what are the need for package switches, as well as how they differ from circuit breakers?

A packet switch is a switching device for turning on and off electric circuits, actually for the same purposes as circuit breakers. He got this name due to the fact that it consists of the same type of elements (packages) assembled on the same axis and secured with pins. Thus, in production from the same parts you can assemble a switching device with any number of poles (contact groups). They are characterized by a rotary movement of the handle device ...

For an electrician, switching equipment is one of the main devices that you have to work with. Circuit breakers carry both switching and protective role. Not a single modern electrical panel can do without automatic machines. In this article we will look at how a circuit breaker is designed and operated.

A circuit breaker is a switching device designed to protect cables from critical currents. This is necessary in order to avoid damage to the conductive conductors of wires and cables in case of interphase faults and earth faults. The main task of the circuit breaker is to protect the cable line from the effects of short circuit currents. The main characteristics of circuit breakers are: rated current (insert a series of currents), switching voltage, time current characteristic ...

Compared to grounding systems such as TN-C and TN-C-S, the TN-S grounding system is particularly reliable and safe. This system appeared and began to gain popularity back in the 40s, having received the first wide distribution in Europe, where to this day it continues to remain deservedly in demand.

In Russia, the TN-S grounding system is also being used more and more often, and year after year it is increasingly competing with other, less reliable, grounding systems, since it is considered today the safest and highest quality of all known approaches to grounding in consumer power networks, especially in residential buildings. Despite the fact that the cost of installing the TN-S system is more expensive than the rest (just because of the need to lay more expensive multicore cables), nevertheless it is chosen on the basis of the requirement to ensure the greatest safety ...

One of the options for a multiphase power supply system is a three-phase AC system. It operates three harmonic EMFs of the same frequency, created by one common voltage source. The EMF data is shifted relative to each other in time (in phase) by the same phase angle equal to 120 degrees or 2 * pi / 3 radians.

The first inventor of the six-wire three-phase system was Nikola Tesla, however, the Russian physicist-inventor Mikhail Osipovich Dolivo-Dobrovolsky made a significant contribution to its development, proposing to use only three or four wires, which gave significant advantages, and was clearly demonstrated in experiments with asynchronous electric motors. In a three-phase AC system, each sinusoidal EMF is in its own phase, participating in a continuous periodic process of electrification of the network, therefore the EMF data is sometimes referred to simply as “phases” ...