RCD - a residual current device or differential current switch is installed to protect a person from electric shock. However, not everyone knows that there are two types of RCDs: electronic and electromechanical. In this article we will talk about what are the differences between RCDs of different types and how to determine the type when buying.

In general terms, the principle of operation of the RCD is as follows: when the current through the phase wire differs from the current through the neutral wire, a relay is activated that disconnects the load. The current is detected using a differential transformer and a polarized relay. A situation where currents of different sizes flow through a phase and neutral wire can occur if a device has a leak on the housing. A leak to the housing occurs if the insulation of one of the conductors of the electrical appliance is damaged and touches the housing ...

When repairing an apartment, lighting issues are usually considered without special responsibility, and they install lamps as you like, estimating the brightness of the light "by eye". However, lighting is an important part of any construction, both from a design and from an engineering point of view. Moreover, there are state documents that regulate these issues, such as SNIP 23-05-95 "Natural and artificial lighting."

This article will talk about how to calculate LED lighting for the home. Although the calculations for industrial and other types of premises, as well as using other types of light sources, are generally similar. The purpose of calculations and lighting design is to achieve normalized lighting for a particular room. Each room has its own lighting standard. It can be calculated based on the class of visual work ...

In electronics, signals are divided into: analog, discrete and digital. To begin with, all that we feel, see, hear, for the most part, is an analog signal, and what a computer processor sees is a digital signal. It doesn’t sound very clear, so let's deal with these definitions and how one type of signal is converted to another.

In electrical representation, an analog signal, judging by its name, is an analog of a real value. For example, you feel the temperature of the environment constantly, throughout your life. There are no breaks. At the same time, you feel not only two levels of “hot” and “cold”, but an infinite number of sensations that describe this value.For a person, “cold” can be different, this is autumn coolness and winter frost, and light frosts, but not always “cold” is a negative temperature, like “heat” ...

In all power grids, voltage surges periodically occur that can damage electrical equipment. Network surges for electronics are especially dangerous. To protect themselves from them, people use stabilizers and voltage relays. Voltage relay - a device that disconnects the mains from the load with abnormal voltage values ​​in it.

On modern common voltage relays there is a display or a group of seven-segment LED indicators and several buttons for setting the operating mode. The display or indicators usually show voltage. Less often, there are two of them, and the second displays the current. You can configure the extreme voltage values ​​(upper and lower limits) at which you need to turn off the power to consumers.Depending on the model, LEDs can be installed to indicate network status, operation mode and current position in the setup menu ...

The issue of remote or remote control of electrical equipment has always been and will be relevant, regardless of whether there are automation tools in the system or not. To organize a remote control, it does not matter at all whether a microcontroller is needed; it all depends on the necessary functions assigned to the managed device. In this article, you will learn general information about how to remotely control a microcontroller.

There are two main types of remote communication. Wired - when the control of actuators located in one room (or not the room) is carried out from the control panel or from a button post located in another place. In this case, an electrical wire connection of the control circuits and actuators (relays, contactors, which include mechanisms, such as motors or systems, for example, lighting) is provided ...

To repair the old wiring or laying a new one, you need to select the cable of the desired cross section in order to withstand the expected load. If the old wiring is out of order, you need to replace it, but before changing it to a similar one, find out why there was a problem with the old one. It is possible that there was simply mechanical damage, or the insulation became unusable, and an even more significant problem is the failure of the wiring due to exceeding the permissible load.

What is the difference between cable products, what are the main characteristics? To begin with, it is determined what voltage in the network in which the cables will work. For household networks, cables and wires of the VVG, PUGNP type are often used (only it is forbidden by modern PUE requirements due to the large tolerances on the cross-section during production, up to 30%, and the permissible insulation layer thickness is 0.3 mm, against 0.4 in PUE) ШВВП and others. If you move away from the definitions, the wire from the cable differs minimally ...

Types, characteristics, marking of SMD LEDs Lighting is an important condition for work and human comfort. For a long time, incandescent lamps were used as light sources, then fluorescent lamps, halogen lamps, DRL and DNaT were used for powerful spotlights and flashlights.

In the 21st century, the generation of lighting fixtures has changed, and LED lamps occupy more than half of the market, they are often called foreign lamps or LED lamps. Depending on the design and power, they are either LED COB-matrices, or assemblies of individual LEDs. The first LED fixtures and lamps were built on the basis of 5-mm output LEDs. They were not distinguished by high energy efficiency, price and reliability, but this was the first step in the development of a new light source. For a long time, such LEDs were used as indicators ...

The thermal relay performs the function of protecting against prolonged overloads, their operation is similar to the operation of the thermal disconnector in circuit breakers. Depending on the magnitude of the overload (deviation from the nominal mode - I / Iн), it is triggered after an appropriate period of time, which can be calculated from the time-current characteristic of the thermal relay. Let's take a closer look at what a thermal relay is and how to choose it correctly.

When the motors are overloaded, the current consumption increases, and its heating increases accordingly.If the engine overheats, the integrity of the insulation of the windings is violated, the bearings wear out faster, they can jam. In this case, the thermal release of the machine may not protect the equipment. To do this, you need a thermal relay. Overloads can occur due to phase imbalance, obstructed movement of the rotor, due to both increased mechanical load ...

Adjusting the brightness of light sources is used to create comfortable illumination of a room or workplace. Adjusting the brightness, it is possible to arrange several circuits that are switched on by individual switches. In this case, you will get a stepwise change in illumination, as well as separate luminous and off lamps, which can cause inconvenience. Stylish and relevant design solutions include a smooth adjustment of the overall illumination, provided all the lamps are lit. This allows you to create both an intimate setting for relaxation, and bright for celebrations or working with small details.

Earlier, when the main light sources were incandescent lamps and spotlights with halogen lamps, there were no problems with adjustment. The usual 220V dimmer was used on the triac (or thyristors). Which was usually in the form of a switch, with a rotary knob instead of keys ...

According to clause 2.1.21. PUE, connection of wires and cables should be carried out in one of the following ways: by welding, crimping, using screw or bolt connections, or by soldering in accordance with applicable instructions approved in the established manner. As you can see, the "twist" is not mentioned here at all. We can safely conclude: twisting is practically prohibited by PUE.

However, let's see why the official attitude to twisting is so unambiguous, what could be the reason for its exclusion from the list of permitted methods of connecting wires, because it is completely clear that this was done for a reason. Allowed: crimping, soldering, welding and screw connection. To begin with, we will consider what are the features of the allowed connection methods, and what is their difference from twisting. Soldering and welding require solidity and the highest possible conductivity of the created permanent connection ...

All modern computers use ATX power supplies. Previously, AT standard power supplies were used, they did not have the ability to remotely start a computer and some circuitry solutions. The introduction of the new standard was associated with the release of new motherboards. Computer technology is rapidly developing and developing, so there was a need to improve and expand motherboards. Since 2001, this standard was introduced. Let's look at how the ATX computer power supply works.

First, take a look at the picture, all the nodes of the power supply are signed on it, then we will briefly consider their purpose. At the input of the power supply there is an electromagnetic interference filter from the inductor and capacitance. In cheap power supplies it may not be. The filter is needed to suppress interference in the power network resulting from the operation of a switching power supply.All switching power supplies can degrade the power supply ...

We already examined the device of bipolar transistors and their operation, now let's find out about what field-effect transistors are. Field effect transistors are very common in both old circuitry and modern.Nowadays, devices with an insulated gate are used to a greater extent, we will talk about the types of field effect transistors and their features today. In the article, I will make comparisons with bipolar transistors in separate places.

A field effect transistor is a semiconductor fully controllable key controlled by an electric field. This is the main difference from the point of view of practice from bipolar transistors, which are controlled by current. An electric field is created by a voltage applied to the gate relative to the source. The polarity of the control voltage depends on the type of transistor channel. There is a good analogy with electronic vacuum tubes ...