For the purpose of switching loads in alternating current circuits, it is convenient to use triacs, which are a type of thyristor, but differing from the thyristor by the ability to conduct current in both directions in the open state. The first designs of triacs were already considered in 1963, then, for example, the Mordovian Research Electrotechnical Institute already filed a patent for a symmetric thyristor (Patent SU 349356 A, Dumanevich AN and Evseev Yu.A.), and General Electric was engaged in commercial implementation of the same product called "Triac" in the west.

Whereas the thyristor has a clearly defined cathode, anode, and control electrode, the triac has a cathode and anode changing their positions during its operation, depending on the current direction at the current moment. Of course, the signal to the control electrode (gate) of the triac is always supplied relative to a specific conditional cathode, but the current ...

Modern digital technology requires high accuracy, so it is not surprising that almost any digital device, which would not catch the attention of the average man today, contains a quartz resonator inside. Quartz resonators for various frequencies are necessary as reliable and stable sources of harmonic oscillations, so that the digital microcontroller could rely on the reference frequency and operate with it in the future, during the operation of the digital device. Thus, a quartz resonator is a reliable replacement for an oscillatory LC circuit.

If we consider a simple oscillatory circuit, consisting of a capacitor and an inductor, it quickly becomes clear that the quality factor of such a circuit in the circuit does not exceed 300, moreover, the capacitance of the capacitor will float depending on the ambient temperature, the same will happen with the inductance ...

Most people, one way or another confronted with electronics, the basic device of field-effect and bipolar transistors should be known. At least from the name “field effect transistor”, it is obvious that it is controlled by the field, the electric field of the gate, while the bipolar transistor is controlled by the base current.

Current and field are a cardinal difference. For bipolar transistors, the collector current is controlled by changing the control current of the base, while to control the drain current of the field effect transistor, it is enough to change the voltage applied between the gate and the source, and no control current is needed anymore. The advantage of field-effect transistors, in comparison with bipolar ones, is obvious: field-effect transistors have a high input resistance in direct current, and even control at a high frequency does not lead to significant ...

The New Year is coming soon! On the shelves of stores next to tangerines, sweets and champagne, Christmas toys appear: colorful balls, tinsel, all kinds of flags, beads and, of course, electric garlands. Perhaps the usual garland of multi-colored light bulbs cannot be bought. But various flashing lights, mainly of Chinese manufacture, simply can not be counted. Microscopic bulbs can be placed on a piece of cardboard or woven into a carpet of wires, which can decorate an entire window immediately.

Christmas tree garlands are also very diverse, especially the external design, design. The cost of such garlands is small, as, in fact, the power of the bulbs.Most garlands have a small plastic box with one button, a cord with a power plug and wires going to a garland of colorful lights. Garland design can be the most diverse. ...

New Year holidays come as always unexpectedly and bring with them a lot of pleasant trouble. It’s time to think about gifts, first of all for children, for adults to set the table, pick up good music and be sure to put a Christmas tree, which to dress up, so that the guests would have fun and cozy. And the first thing to hang on the tree is, of course, Christmas tree garlands. All other toys, as a rule, are hung after garlands. Next, we will talk about the device of a variety of different Christmas garlands - old and modern.

In ancient times, when there was no electricity, and the New Year was already celebrated, special New Year candles were lit on the Christmas tree. This decoration was very fire hazard. But these times have already passed, everyone began to use electric garlands. These were ordinary small bulbs from a flashlight or from the backlight of a scale in a radio receiver, connected in series. From such bulbs, garlands were made by enthusiasts ...

The term “sensor” itself means a mechanism designed to measure a parameter in order to further process the measurement result. The sensor circuit generates a signal in a convenient form for transmission, then the signal is converted, processed or stored. Without sensors in some modern areas of industry, and in many equipment of various kinds, just can not do.

Electronics today makes it possible to manufacture electronic sensors capable of monitoring processes by several parameters at once, which greatly expands the possibilities for constructing complex measuring and actuating devices. The sensor necessarily contains in its design a sensitive element and often a converter part. The main characteristics of electronic sensors are their sensitivity and measurement error. To date, analog and digital sensors ...

In this article, we will discuss the topic of selecting analogues of bipolar and field effect transistors. What parameters of the transistor should you pay attention to in order to choose the appropriate replacement? What is it for? It happens that when repairing a device, say, a switching power supply, the user is forced to go to the nearest store of electronic components, but the assortment does not contain just such a transistor that failed in the device circuit. Then you have to choose from what is available, that is, select an analogue.

And it also happens that the burned-out transistor on the board was one of those that have already been discontinued, and then it’s just the right thing to do is the datasheet available on the network, where you can see the parameters and select the appropriate analogue from those currently available. One way or another, you need to know what parameters to choose, and this will be discussed later.First, let's talk about bipolar transistors ...

An article “What is a switching power supply and how does it differ from a regular analogue”, which tells about the UPS device, has already been published on the site. This topic can be supplemented with a little story about the repair. Under the acronym UPS is often referred to uninterruptible power supply. In order to avoid discrepancies, we agree that in this article it is a Switching Power Supply.

Almost all UPSs used in electronic equipment are built according to two functional schemes. According to the half-bridge scheme, as a rule, fairly powerful power supplies, for example computer ones, are carried out.According to the two-stroke scheme, power supplies for high-power UMZCH pop art and welding machines are also manufactured. Anyone who has ever repaired amplifiers with a capacity of 400 or more watts knows perfectly well what weight they have. It is, of course, about UMZCH with the traditional ...