If we take a brand-new lithium-ion battery, let's say size 18650 with a nominal capacity of 2500mAh, bring its voltage to exactly 3.7 volts, and then connect it to an active load in the form of a 10-watt resistor with a value of R = 1 Ohm, then what is the constant current we expect to measure through this resistor?

What will happen there at the very first moment of time, until the battery almost starts to discharge? In accordance with Ohm's law, it would seem that there should be 3.7A, since i = U / R = 3.7 / 1 = 3.7 [A]. In fact, the current will be slightly less, namely, in the region of I = 3.6A. Why is this going to happen? The reason is that not only the resistor, but the battery itself has some internal resistance, since the chemical processes inside it cannot occur instantly. If you imagine a battery in the form of a real two-terminal, then 3.7V - this will be its EMF ...

If you think hard, then all kinds of applications for such a seemingly simple thing as an inductor simply can not be counted. In one article, we recall only a few of them. Meanwhile, human ingenuity and talent do not tire of creatively expressing themselves by inventing and developing more and more new devices and mechanisms based on inductors.

It would seem that here you can build? A simple coil of wire, it can be a core of a certain shape, and the current passing through the wire in a constant, variable or pulsed form. And yet, without inductors, all modern electrical engineering simply could not exist. Let's take a closer look. Elevator washers have been used worldwide for many years to load ferromagnetic waste. The electromagnet just clings to a crane hook ...

Fluorescent lamps (LL) are used for lighting and now, despite the fact that LED lamps make them a strong competition. Linear tubular lamps are more often installed in offices, garages, at enterprises, compact fluorescent lamps (CFLs) are installed in everyday life and in the same types of premises as listed above. For them there are characteristic malfunctions, so in this article we will consider how to fix a fluorescent lamp.

Fluorescent lamps differ in the shape of a tubular bulb, they are linear and curly. It is typical for CFL, where the flask is a tube twisted into a spiral or U-shaped. This is necessary to reduce the size while maintaining the length and area of ​​the emitted surface. In the general case, the LL flask is a glass tube into which mercury vapor and inert gases are pumped. Two spirals are installed in the flask, one at each of its ends ...

Each house has a mass of household appliances, costing from units to tens and even hundreds of thousands of rubles. In order for her to serve as long as possible, she needs to be monitored, taken care of and carry out all maintenance work, if any. However, only power surges remain a danger.

In household electrical networks, they occur frequently, they can be caused by switching of powerful electrical equipment, as well as problems on the lines, such as poor contact, dilapidated supports, and so on. To reduce the risk of equipment failure due to poor power supply, you can use voltage stabilizers 220V. In this article we will consider what they are and how they differ.Before starting a review of the types of electric stabilizers, we will consider what an autotransformer is, because it underlies most modern stabilizers. Autotransformer - differs from the usual prefix "auto" in the name ...

From time to time on the Internet you can find reports about how one of the cyclists was hurt by electric shock from his own bicycle when he was driving under a high-voltage power line with a voltage of 100 kV or more. No one can give exact and intelligible answers to such requests: on the forums, disputes arise on this issue, but many network users have guesses on this subject.

It’s one thing when it comes to step voltage, it would be quite understandable if the wire detached from the power line were in contact with the ground, and then standing on the ground someone could accidentally find themselves in the wrong place at the wrong time dangerous step voltage. This is a well-known phenomenon, for its reason in 1928 three horses died on the Leningrad pavement in one day. But in the messages given by the cyclists, the speech about the step voltage does not seem to go ...

Sensors are used in a wide variety of circuits and projects. No automation can do without them. We are interested in them, because to simplify the design and popularization of electronics, the Arduino project was created. This is a finished board with a microcontroller and everything you need to work with it and program it. In this article, we will consider sensors for Arduino, but they can also be used with other microcontrollers.

What are the sensors? Sensors are the eyes, ears, and other sensory organs of a microcontroller or other control device. They are distinguished by the nature of the signal and by purpose. By the nature of the signal, they are divided into analog and digital. If we talk about Arduino, then, when receiving information from sensors, we processed a digital signalor we measure the voltage from the analog output of the module. As already mentioned, sensors are digital and analog...

One of the most common tasks for an “apartment” electrician is to install one or more fixtures. Usually this does not create any problem, because connecting one switch is quite simple. But often you need to make sure that the bulb turns on from several places, for example, from two, more - less often. In this article, we will consider lighting control schemes with the help of several switches.

This problem is often found in private houses on a precinct, for example, near the front door and gate, at the entrance to the courtyard, as well as in houses with several floors, so that it is possible to turn on the light from any floor and safely go down the stairs. The main problem is that if you install two ordinary switches on one lamp, then no matter how you connect them, either they must be turned on, or both off. Therefore, it will not work to control the lighting ...

If there is a marking on the transformer, then the question of determining its parameters is settled by itself, you just need to drive this data into the search engine and instantly get a link to the documentation for our transformer. However, marking may not be, then we need to calculate these parameters ourselves.

To determine the rated current and power of an unknown transformer by its appearance, it is necessary first of all to understand what physical parameters of the device are determining in this context. And such parameters are primarily the effective cross-sectional area of ​​the magnetic circuit (core) and the cross-sectional area of ​​the wires of the primary and secondary windings.We will talk about single-phase transformers, the magnetic cores of which are made of transformer steel, and are designed specifically for operation from a network of 220 volts 50 Hz ...