How can I get electricity using ordinary household gas? In order to receive electricity directly from a gas burner or other heat source, heat generators are used. Just like a thermocouple, their principle of operation is based on the Seebeck effect, discovered in 1821.

The mentioned effect is that in a closed circuit of two dissimilar conductors an emf appears if the junctions of the conductors are at different temperatures. For example, a hot junction is in a vessel of boiling water, and the other in a cup of melting ice.

The effect arises from the fact that the energy of free electrons depends on temperature. In this case, the electrons begin to move from the conductor, where they have a higher energy in the conductor, where the energy of the charges is less. If one of the junctions is heated more than the other, then the difference in the energies of the charges on it is greater ...

At first glance, new materials, superconductors, seem to be advantageous to use almost everywhere where magnetic fields and electric currents are used. But is it?

In order to navigate many technical works with superconductors, it should be borne in mind that there are no superconductors, as such, at all. These are the usual metals known to all, under special conditions exhibiting unusual properties.

Aluminum, for example, conducts electric current well at room temperature, therefore it is considered one of the best conductors. The magnetic field in it is slightly enhanced: such materials are called paramagnets. Aluminum perfectly transmits heat, which means that it can be considered a heat conductor. When cooled to extremely low temperatures, the properties of some metals change significantly ...

The general pattern of our time is the narrowing of the gap between a particular discovery and its implementation. Once this interval reached hundreds of years, now it has decreased to a minimum. For example, the introduction of photography is 112 years behind its opening. Mineral fertilizers began to be used 70 years after they were created, telephone communications - after 50 years, broadcasting - after 35, radiolocation after 15, television - after 12, atomic bomb - after 6 years, a transistor - after 3, and a laser - after only 2 of the year.

The beginning of the technical use of superconductors dates back to 1955, when the first electromagnet was created with their help. 56 years have passed since the discovery of superconductivity to its introduction. What is the matter? According to some British physicists, this delay is due to two reasons: the insufficient development of cryogenic technology and the discovery of only soft, pure superconductors ...

Before you start the story about temperature sensors, you should understand what temperature is in terms of physics. Why does the human body feel a change in temperature, why do we say that today it’s warm or just hot, and the next day it’s cool, or even cold.

The term temperature comes from the Latin word temperature, which in translation means normal condition or proper displacement. As a physical quantity, temperature characterizes the internal energy of a substance, the degree of mobility of molecules, the kinetic energy of particles in a state of thermodynamic equilibrium. An example is air, whose molecules and atoms move randomly. When the speed of movement of these particles increases, they say that the air temperature is high ...

The electrical term “anchor” is much older than the word electrical engineer. In the era of great geographical discoveries and the development of navigation in the oceans, there was an acute need for magnetic compasses, the main part of which was the magnetic needle. These arrows were made of iron and magnetized by natural magnets. There were simply no others.

Good magnetization also required good magnets. To enhance the action of natural magnets, they were reinforced with iron, attaching it to the stone using non-magnetic frames made of copper, silver and even gold.

Magnets were expensive. The magnet set also included a removable iron block, which “stuck” to the poles of the magnet. This bar had on one side a ring, hook or decorative copy of the sea anchor ...

Switching devices or just contacts are very widely used in various electrical and radio equipment. In order to improve operational properties, first of all, the service life and reliability of the connection, magnetically controlled sealed contacts called reed switches were developed.

The first samples of such contacts appeared in the 30s of the last century, and the first magnetically controlled contact was invented in 1922 in St. Petersburg by Professor V. Kovalenkov, for which he was issued the USSR copyright certificate No. 466.

In fact, this was the very first magnetically controlled contact, only without a sealing shell. A similar contact was first placed in the sealing shell by an American engineer W.B. Ellwood only in 1936 ...

For any layman in our country, the concept of energy conservation is an energy-saving light bulb and, at best (if you have a technical background), smart home electrical appliances. Basically, most people, with energy conservation issues, are faced precisely in these areas of their life (if the housing and communal services system does not work).

For the average person who does not need to delve into problems of a national scale, participation in the government’s energy conservation program means replacing the old Illich lamp with an energy-saving lamp. But energy-saving lamps, today are tens of times more expensive, but people still buy, because according to Law 261-f3 from 2012. incandescent lamps in our country will not be produced ...

Cable heating: from underfloor heating to roofs without icicles.

Recently, cable electrical heating systems are finding wider application. The range of applications of such systems is becoming wider, their use is more economical, reliable and efficient. More recently, the scope of the heating cable was limited, perhaps, to the installation of underfloor heating.

Currently, the assortment of heating cables and even thermofilms has become much more extensive, which allowed heating anything you like, from water pipes to roofs of buildings. But first, remember how it all began. The history of the development of the warm floor is rooted in the distant past and dates back several centuries, even if not millennia ...