Indicators and signaling devices on an adjustable zener diode TL431


Indicators and signaling devices on an adjustable zener diode TL431The TL431 integrated stabilizer is mainly used in power supplies. However, for it you can find many more applications. Some of these schemes are provided in this article.

This article will talk about simple and useful devices made using the TL431 chip. But in this case, you should not be afraid of the word “microcircuit”, it has only three conclusions, and outwardly it looks like a simple low-power transistor in the TO90 package.

TEXAS INSTRUMENTS was at the forefront of the semiconductor era. All this time, she has been in the first place in the list of world leaders in the production of electronic components, firmly holding herself in the top ten or, as they say more often, in the world ranking TOP-10. The first integrated circuit was created back in 1958 by Jack Kilby, an employee of this company.

Among the very first in the list of “magic” microcircuits, one should probably consider the adjustable voltage regulator TL431 ...

 

Pulse relays for lighting control and their use

Pulse relays for lighting control and their useOften, 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 circuit breakers, 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 ...

 

How to detect closed loops

How to detect closed loopsIf physics was well taught at your school, then you probably will 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 galvanometer in appearance 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 ...

 

Logic chips. Part 3

Logic chipsIn the second part of the article, we talked about the 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 panels

Electrical panelsElectrical 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 ...

 

Uninterruptible power supply for your computer


Uninterruptible power supply for your computerUPS 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 voltage surges ...

 

Placement of sockets and switches


Placement of sockets and switchesHow 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 ...

 

What is protective grounding and how does it work


protective groundingProtective 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 dead-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 ...