In many descriptions, the comparator is compared with conventional lever scales, as in a bazaar: a standard is placed on one bowl - weights, and the seller begins to put goods, such as potatoes, on the other. As soon as the weight of the product becomes equal to the weight of the weights, more precisely a little more, the cup with weights rushes up. Weighing is over.

The same thing happens with the comparator, only in this case the role of weights is played by the reference voltage, and the input signal is used as a potato. As soon as a logical unit appears at the output of the comparator, it is considered that the voltage comparison has occurred. This is the very “a bit more”, which in the directories is called the “threshold sensitivity of the comparator”. Novice hams - electronics engineers often ask how to check a particular part. To check the comparator, you don’t need to collect any complex circuit ...

The name comparators comes from the Latin compare - compare. Devices in which measurement is carried out by comparing with a standard work on this principle. For example, equal-arm scales or electric potentiometers.

The principle of action distinguishes between electrical, pneumatic, optical and even mechanical comparators. The latter are used for checking end length measures. The first comparator was used in Paris by Lenoir in 1792.

In this article we will not consider in detail mechanical and other comparators, since our task is voltage comparators. At present, comparators are mainly used in integrated design. Few people would think of assembling a comparator from discrete transistors. Moreover, comparators are used as part of some chips ...

If you collect all the systems and standards of a smart home that are offered on the Internet today in one place, you will have to urgently measure IQ (the amount of intelligence) and decide who is the boss in the house. Products of the modern Z-Wave standard such a procedure will not hinder.

The created alliance, or open consortium, to support the new standard impresses with its composition: from the world leader in the production of Intel chips to the world electrical leader Danfoss A / S. And among 200 members of the consortium, Panasonic, Logitech, and dozens of well-known companies, often fiercely competing with each other, “were modestly lost”.

What led them all to a modest market niche (or abode) of home automation? To answer this question, let us take a closer look at the very concept of the Z-Wave standard and its prospects and its prospects. The technology was developed at the beginning of the 21st century by the small company Zensys ...

The need for a re-earthing device at the entrance to the country house is dictated by the current regulations of the PUE. In accordance with paragraph 1.7.61 of these rules, it is recommended to install a grounding device with a current spreading resistance of 30 Ohms for a three-phase network and 60 Ohms for a single-phase network at the input to any electrical installation of the TN grounding system. These recommendations can be neglected only in the case of the presence and use of natural grounding conductors (metal structures partially located in the ground and meeting the requirements of the PUE for resistance).

Since it is far from always possible to choose a suitable natural grounding conductor, the device of a separate grounding device (charger) at the entrance to the newly built country house becomes the most rational technical solution. Moreover, it does not require special material costs. The grounding device includes a grounding conductor ...

Almost everyone who was interested in energy heard about the prospects of MHD generators. But the fact that these generators have been in the status of promising for more than 50 years is known to few. The problems associated with plasma MHD generators are described in the article.

The story with plasma or magnetohydrodynamic (MHD) generators is surprisingly similar to the situation with thermonuclear fusion.

It seems that you need to take only one step or make a little effort, and the direct conversion of heat into electrical energy will become a familiar reality. But another problem pushes this reality indefinitely. First of all, about the terminology. Plasma generators are one of the varieties of MHD generators. And those, in turn, got their name by the effect of the appearance of an electric current ...

In a previous article, we started introducing a semiconductor diode. In this article we will consider the properties of diodes, their advantages and disadvantages, various designs and features of application in electronic circuits.

The current-voltage characteristic (CVC) of a semiconductor diode is shown in the figure. Here, in one figure, the I – V characteristics of germanium (blue) and silicon (black) diodes are shown. It is easy to notice that the characteristics are very similar. There are no numbers on the coordinate axes, since for different types of diodes they can vary significantly: a powerful diode can pass a direct current of several tens of amperes, while a low-power one can only transmit several tens or hundreds of milliamps. There are a great many diodes of different models, and all of them can have different purposes, although their main task, the main property is ...

Diodine - the simplest device in the glorious family of semiconductor devices. If we take a plate of a semiconductor, for example Germany, and introduce an acceptor impurity into its left half, and into the donor right, then on the one hand we get a type P semiconductor, respectively, on the other type N. In the middle of the crystal we get the so-called P-N junction.

The figure below shows the conventional graphic designation of the diode in the diagrams: the cathode output (negative electrode) is very similar to the “-” sign. It’s easier to remember. In total, in such a crystal there are two zones with different conductivities, from which two leads come out, therefore the resulting device is called a diode, since the prefix "di" means two. In this case, the diode turned out to be a semiconductor, but similar devices were known before: for example, in the era of electron tubes there was a tube diode called a kenotron ...

Integral timer 555 found another application in three-phase inverters, or as they are often called frequency-controlled drives. The main purpose of "chastotnikov" is the regulation of the speed of three-phase asynchronous motors. In the literature and on the Internet you can find many schemes of home-made frequency drives, the interest in which has not disappeared to date.

The whole idea is this. The rectified mains voltage with the help of the controller is converted to three-phase, as in an industrial network. But the frequency of this voltage can change under the influence of the controller. The methods of change are different, from simple manual control to regulation by an automation system.

The block diagram of a three-phase inverter is shown in the figure. Points A, B, C show the three phases to which the induction motor is connected. These phases are obtained by switching transistor switches ...