Often, one switch is not enough to control the lighting, for example, when you need to turn on the light at the beginning of a long corridor and turn it off when you reach the end. This is realized by installing pass-through switches, quite simply, you just need to lay a three-core cable between them. But if you need to implement lighting control from more places, there are difficulties with laying wires to the cross switches, their connection ... It is much easier to use a special relay in such schemes. In this article we will consider what a pulse relay is and how to work with it.

Conventional relays work simply when voltage is applied to the coil - the contacts close (or open), when not, they return to their original position. In pulse relays, or as they are also called - bistable - this is not the case. When a voltage pulse is applied to the relay, it turns on; when the next pulse is applied, it turns off. Conventional bistable relays are used in automation and security systems, when applying a pulse of the same polarity ...

If physics was well taught at your school, then you probably remember the experience that clearly explained the phenomenon of electromagnetic induction.

Outwardly, it looked something like this: the teacher came to the classroom, the attendants brought in some appliances and placed them on the table. After explaining the theoretical material, a demonstration of experiments began, which clearly illustrates the story.

To demonstrate the phenomenon of electromagnetic induction, a very large inductor, a powerful direct magnet, connecting wires and a device called a galvanometer were required.

The appearance of the galvanometer was a flat box a little larger than a standard A4 sheet, and behind the front wall, which was closed by glass, a scale with a zero in the middle was placed. Behind the same glass one could see a thick black arrow ...

In the second part of the article, we talked about conditional graphic designations of logical elements and about the functions performed by these elements.

To explain the principle of operation, contact circuits performing the logical functions of AND, OR, NOT and AND-NOT were given. Now you can begin to practical acquaintance with the K155 series microcircuits.

The basic element of the 155th series is the K155LA3 chip. It is a plastic case with 14 leads, on the upper side of which is marked and a key that indicates the first output of the chip.

The key is a small round mark. If you look at the microcircuit from above (from the side of the case), then the conclusions should be counted counterclockwise, and if from below, then clockwise ...

Electrical shield…. What is it? This is the beginning of the entire electrical part of the building, and it doesn’t matter if it’s a huge factory in a metropolis or a modest grandmother’s house in the village. Everywhere there is an electric shield.

In this article we will get acquainted with the most common electrical panels that can be found in everyday life. For example, take the most ordinary apartment building.

So where does the electrical part of the house begin? Depending on the project, on the power that is supplied to the house, the electrical part begins with an electrical panel. In the switchboard there can be a switchgear (input distribution device) or main switchboard (main switchboard). It is to these installations that power cables from a transformer substation (TP) come ...

UPS is a guarantee of the safety of your computer.An article about why uninterruptible power supplies are needed, what types they are and how to service them.

Given the relatively high cost of computer equipment and the low quality of electric energy in our homes, an uninterruptible power supply (UPS) is simply an irreplaceable thing.

Under certain circumstances, an uninterruptible power supply can not only ensure the operation of the computer in the event of a power failure, but also save it from damage. In addition, due to the built-in protection, the uninterruptible power supply saves the equipment connected to it during a thunderstorm from possible surges ...

How and where is the best place for sockets and switches.

Everyone, sooner or later, thinks about repairing a house, an apartment. When planning a repair, the question arises about the location of sockets, switches, lamps. As a rule, during repair, the old wiring is completely replaced with a new one. In this article, we will consider options for the most optimal placement of sockets and switches.

There are no uniform rules, standards and formulas for determining the number of outlets. Each apartment, each house with its inhabitants is individual and requires an individual approach to determining places for the location of sockets, switches ...

Protective grounding, purpose and principle of action.

Currently, there are several different power supply systems for consumers with voltages up to 1000 V, however, in Russia, the main one in this case is a system with a grounded neutral. It is such a system that is used in each of our homes.

With the apparent complexity of the name, everything is extremely simple. In such a system, the neutral point of the transformer at the substation is directly connected to the ground. The main measure of protection against accidental undervoltage in this case is protective grounding, that is, a special connection of any metal part of the household appliance with the neutral of the transformer ...

Did the house lamp burn out? The easiest way is to throw it in the trash, but you can make it ... another, and if there are several lamps that have burned down, then you can do it .... by repair.

If you at least once held a soldering iron in your hands, then this article is for you.

You can turn on the fluorescent lamp up to 30 watts, without a starter and throttle, using a small scarf removed from our economy lamp. At the same time, it will light up instantly, with a decrease in voltage will not ‘Blink’. This lamp burns out in two ways ...

Electricity supply to apartment buildings and private houses.

How many of us think about how electricity gets into our home. Remembering school physics lessons, you can draw about the following diagram:

Electricity is generated at power plants, then transmitted through the high-voltage power lines (high-voltage power lines), then it gets to city and regional distribution zones.

After the RES, electricity goes to the transformer substations, where it drops to the required 380/220 Volts. And these same 380/220 volts we get in the end at home. Here we will consider the last step in more detail ...

What are touch switches? Initially, the concept of touch switches meant switches with a contact plate, when touched, the load turned on and off. There are no mechanical moving parts in the touch switches.

With the advent of new devices, the concept of touch switches has changed a bit.Now, the concept of a touch switch includes all devices for which control is not required to use any direct physical impact.

The most common touch switches include: IR sensors (motion sensors), volume sensors, acoustic sensors (responsive to sound), touch switches in the form of an ordinary switch, but without a movable key ...

An electrician is the science of contacts ... Almost every electrician knows, or at least heard this phrase. And the fact that this phrase is not taken from the ceiling, many learn in practice.

Almost all the problems associated with electricity arise due to congestion in the wiring, which is quite relevant today, or because of poor contact in the soldering (dose) boxes or in the end devices (sockets, switches, lamps) themselves.

How is it better to connect the wires so that there is a reliable contact and so as not to have problems in the future? To begin, let's look at which compounds are most often found ...

Logical elements operate as independent elements in the form of microcircuits of a small degree of integration, and they are included as components in microcircuits of a higher degree of integration. Such elements can be counted more than a dozen.

But first, we’ll only talk about four of them - these are the elements AND, OR, NOT, AND-NOT. The main elements are the first three, and the AND-NOT element is already a combination of the AND AND NOT elements. These elements can be called "bricks" of digital technology. First you need to consider what is the logic of their action?

Recall the first part of the article on digital circuits. It was said that the voltage at the input (output) of the microcircuit within 0 ... 0.4 V is a logic zero level, or a low voltage level. If the voltage is within 2.4 ... 5.0 V, then this is the level of a logical unit or a high level voltage ...