If we consider a direct current, then it can not always be perfectly constant: the voltage at the source output may depend on the load or on the degree of discharge of the battery or galvanic battery. Even with a constant stabilized voltage, the current in the external circuit depends on the load, which confirms Ohm's law. It turns out that this is also not quite a constant current, but such a current cannot be called variable either, since it does not change direction.

A variable is usually called voltage or current, the direction and magnitude of which does not change under the influence of external factors, such as a load, but is completely "independent": this is how the generator generates it. In addition, these changes should be periodic, i.e. repeating over a certain period of time called a period. If the voltage or current changes anyhow, without worrying about the frequency and other regularities, such a signal is called noise ...

In the article "Capacitors: purpose, device, principle of action" was talked about electrolytic capacitors. They are mainly used in DC circuits, as filter capacities in rectifiers. Also, they can not do without decoupling power supply circuits of transistor cascades, stabilizers and transistor filters. Moreover, as was said in the article, they do not allow direct current, but do not want to work on alternating current.

Non-polar capacitors exist for AC circuits, and many of their types indicate that the operating conditions are very diverse. In those cases when high stability of parameters is required, and the frequency is high enough, air and ceramic capacitors are used. The parameters of such capacitors are subject to increased requirements ...

The phrase that learning is never too late is now more relevant than ever. It is no secret that in today's rapidly changing world, competition in the labor market is intensifying significantly. And now, when hiring, organizations require much more from their employees.

Already now the old scheme does not work, when, having studied once at the institute, it is possible to work at one workplace almost all of life. According to sociologists, in the next 40-50 years, a job change by one person will occur on average once every 10-12 years. And that means that you will have to intensively study, retrain, improve qualifications, competence in your field of activity.

How many middle and older people would like to study? Admit it - you want to keep up to date, do you want to learn and learn new things? This is where various techniques and ways of teaching adults come to the first place ...

Having contacted the electrical installation at your own site or in your own apartment, you can very soon notice that the cables and wires used in the installation are mainly copper, less often aluminum. With all the variety, there are simply no other materials. Further, you can notice that the structure of the cores of these cables also varies: the core can consist of many wires, but it can be whole. The core structure affects the flexibility of the cable, but does not affect its conductivity.

It seems that the spectrum of cable characteristics ends there. But where then is such a variety of brands? VVG, SIP, PVS, ShVVP - how do they differ from each other? For the most part, insulation properties. Let's talk about this in more detail. VVG cable marking means: external insulation from polyvinyl chloride, core insulation - also from polyvinyl chloride, flexible cable conductors. Although the flexibility of the VVG cable is relative ...

Any electrical circuit consists of a source and a receiver of electrical energy, interconnected by wires. What is a wire, it is understandable, but as a receiver and source can be any combination of various devices.

The source of electrical energy can be a conventional battery or a powerful transformer substation. The energy receiver shown in the figure is also the most diverse - from a flashlight for a flashlight to an apartment building. Connecting wires will also correspond to power consumption. Further, only low-power sources and receivers will be considered not more powerful than the mentioned light bulb.

For a power source, the receiver is a load. That is what it is most often called. Further in the article, resistors will be used as a load, in some cases light bulbs ...

An electrician in the course of his professional activity very often has to perform many complex calculations of various parameters of electrical systems, depict electrical circuits, choose various equipment. This work is time consuming. There are many useful programs for electricians, which are designed to calculate various parameters, drawing circuits, etc.

The main goal of these programs is to greatly simplify the work of an electrician, minimizing the time spent on performing calculations or drawing diagrams, which is often faced by an electrical engineer. In this article, we will consider the most common programs for electricians. We begin the review of programs with the multifunctional program "Electric". The capabilities of this program are very wide. So, in this program you can ...

The modern assortment of wires and cables is quite wide. The buyer is presented with a large assortment of cable and wire products of various designs of cores, as well as with different insulation coatings. As a rule, all conductors and cables are specially marked, which shows the characteristics of a product. Below is a breakdown of the most common brands of wires and cables.

Electrical cables and wires are marked with letters and numbers. Consider the letter abbreviations, that is, the marking that is used to designate cables with polyvinyl chloride (PVC) and rubber insulation in accordance with GOST 16442-80, TU 16.K71-335-2004, TU16.71-277-98. “A” (first letter) - indicates the material of the core, in this case aluminum, and in the absence of this letter the material is copper ...

In this article, we will consider the question of how to find the phase and zero using a probe and a multimeter.

If it is necessary to service apartment electricians, in particular replacing sockets, lighting switches or conducting minor repairs, it becomes necessary to determine the phase and zero. If a person has some knowledge in the field of the basics of electrical engineering, then it will not be difficult for him to find phase and zero. But what if you do not have these skills? Finding phase and zero is not as complex a process as it might seem. Consider several methods for determining phase and zero.

First, we will determine what phase and zero are. Our entire energy system is three-phase, including low-voltage lines that feed residential buildings and apartments. As a rule, the voltage between any two phases is 380 volts - this is a linear voltage ...