The economic efficiency of using thermoelectric refrigerators in comparison with other types of refrigerating machines increases the more, the smaller the volume of the cooled volume. Therefore, the most rational at the present time is the use of thermoelectric cooling for household refrigerators, in food liquid coolers, air conditioners, in addition, thermoelectric cooling is successfully used in chemistry, biology and medicine, metrology, as well as in commercial cold (maintaining the temperature in refrigerators) , refrigeration transport (refrigerators), and other areas

The effect of the occurrence of thermoEMF in soldered conductors is widely known in the art, the contacts (junctions of junctions) between which are maintained at different temperatures (Seebeck effect). In the case when a constant current is passed through a circuit of two dissimilar materials, one of the junctions starts to heat up, and the other starts to cool. This phenomenon is called the thermoelectric effect or the Peltier effect ...

In this article we will consider the basic schemes for switching on single-phase and three-phase electric meters. I want to note right away that the switching circuits of induction and electronic electric meters are absolutely identical.

The mounting holes for fixing both types of electric meters should also be exactly the same, however, some manufacturers do not always adhere to this requirement, therefore, sometimes there may be problems installing an electronic electric meter instead of induction in terms of mounting on the panel.

The clamps of the current windings of electric meters are indicated by the letters G (generator) and N (load). In this case, the generator clamp corresponds to the beginning of the winding, and the load clip corresponds to its end.

When connecting the meter, it is necessary to ensure that the current through the current windings passes from their beginnings to the ends. To do this, the wires from the power supply side must be connected to the generator terminals (terminals G) of the windings, and the wires extending from the meter to the load side must be connected to the load terminals (terminals H) ...

Daedalus is the pseudonym for the English scientist David Jones. For many years he led the Daedalus column in New Scientist magazine, where he shared his ideas and inventions with readers of the magazine.

Daedalus’s inventive fantasy is always based on scientific reality. And strangely enough, approximately 17% of inventions in one form or another were subsequently taken seriously, patented, implemented, and some, as it turned out, had already been implemented before! Some of Daedalus’s ideas published in the magazine were demonstrated “in practice” - in television popular science programs ...

The homopolar theory of terrestrial magnetism states that in the convection currents of molten iron moving in the Earth’s core under the influence of the planet’s magnetic field, an electric current arises, which in turn supports this field.

Daedalus sees in the existence of these currents the key to solving the energy problem - you just need to lower the electrodes so deep as to connect to the deep currents ...

In the beginning of the twentieth century, fierce debates between specialists over the advantages and disadvantages of using direct and alternating current circuits for power supply. It so happened that preference was given to three-phase AC circuits.Industrialists, calculating the volume of capital costs for the creation of power supply systems, have chosen, it would seem, the most optimal option.

The decisive role in the ubiquity of three-phase AC networks was played by the simplicity of obtaining torque with a minimum number of phases. Against direct current, such arguments were put forward as the high cost and low reliability of engines, the complexity of energy conversion. But that was then. What now? The practical experience gained over many years of the development of the electric power industry gives, in my opinion, devastating results.

The first one. From the course of the theoretical foundations of electrical engineering, it is known that in order to transfer maximum power to the load in alternating current circuits, the condition of equal source resistance to line resistance and load resistance must be met. It follows that the theoretically achievable efficiency for AC circuits is 33% ...

An electronic counter is a converter of an analog signal to a pulse repetition rate, the calculation of which gives the amount of energy consumed.

The main advantage of electronic meters compared to induction ones is the absence of rotating elements. In addition, they provide a wider range of input voltages, make it easy to organize multi-tariff metering systems, and have a retrospective mode - i.e. allow you to see the amount of energy consumed for a certain period - usually monthly; they measure power consumption, easily fit into the configuration of ASKUE systems and have many more additional service functions.

A variety of these functions lies in the software of the microcontroller, which is an indispensable attribute of a modern electronic electricity meter.

Structurally, the electric meter consists of a housing with a terminal block, a current measuring transformer and a printed circuit board on which all electronic components are installed.

The main components of a modern electronic meter are ...

The need to establish electrical equipment is not as obvious as, say, the need to mount it. And the results of the adjustment are not so tangible, tangible as during installation. It would seem that it is simpler: apply voltage to the mounted electrical equipment and, by pressing a button, put it into action.

However, this can only be done in the simplest cases, for example, when lighting is turned on in residential buildings; in the vast majority, electrical circuits after installation are subject to adjustment.

First of all, the electrical equipment must be checked. This is explained by the fact that during the manufacture, transportation and installation of equipment and apparatus, their damage, deviations from the project, latent defects and, finally, just errors, especially when making connections in complex circuits, are possible. If you neglect the check, the result is likely to be a failure in work or a serious accident.

In commissioning, the sequence of operations is of great importance. First, they study the design and technical documentation for the electrical equipment of the launch complex, which is usually represented by the capital construction department of the customer enterprise. Then check the completeness of equipment delivery, compliance with its design. At the same time, the installers not only get acquainted with the design solutions, but also identify shortcomings and errors of the circuit diagrams and correct the wiring diagrams if they are not consistent with the principal ...

The first association that comes to mind with the phrase “smart home” is the automatic inclusion of light in a room when a person appears there and the automatic lighting off when people leave this room. In this article I will give detailed instructions on how to create such an automatic inclusion of light with your own hands, making your home a little smarter.

To implement this idea, the LX-01 motion sensor was taken. The principle of its action is simple - when there is movement in the detection zone, it closes the circuit, thereby including devices connected to it. In the absence of movement, the circuit automatically opens, turning off all devices.

The motion sensor also has the ability to configure, there are three of them - the time interval for switching off, the level of illumination and sensitivity. The time interval for shutdown sets the time during which the sensor will work since the last motion detection. Values ​​are set between 5 seconds and approximately 2 minutes ...

In 1951, the English scientist Lissman studied the behavior of the fish of the gymnasium. This fish lives in opaque opaque water in lakes and swamps of Africa and therefore can not always use sight for orientation. Lissman suggested that these fish, like bats, are used for orientation echolocation.

The amazing ability of bats to fly in complete darkness, without bumping into obstacles, was discovered a long time ago, in 1793, that is, almost simultaneously with the discovery of Galvani. Did it Lazaro Spallanzani - Professor at the University of Pavia (the one where Volta worked). However, experimental evidence that bats emit ultrasounds and are guided by their echoes was obtained only in 1938 at Harvard University in the USA, when physicists created equipment for recording ultrasounds.

Having tested the ultrasonic hypothesis of the orientation of the gymnast experimentally, Lissman rejected it. It turned out that the gymnarch is oriented somehow differently. Studying the behavior of the gymnast, Lissman found out that this fish has an electric organ and begins to generate very weak current discharges in opaque water. Such a current is not suitable for either defense or attack. Then Lissman suggested that the gymnarch should have special organs for the perception of electric fields - sensor system ...