Soldering is the process of joining parts by introducing molten material between them - solder, the temperature of which, as a rule, is lower than the melting temperature of the parts being joined. The purpose of soldering is to obtain a mechanical connection or electrical contact. Further, the article will mainly deal with the soldering of electronic components.

The soldering of metals was used in ancient times. It is believed that this technological operation has existed for at least 5000 years. Even when humanity did not know iron and steel, copper, gold and their alloys became widespread. But even then, master chasers used the connection of parts of products using soldering. Archaeologists have found gold vessels, the handles of which were soldered with gold, as well as alloys of gold and silver. Gold items with traces of soldering were found during excavations of the tombs of the ancient state of Babylon. Scientists dated finds 3200 BC ...

With electricity you need to be on you !!! (time-tested wisdom).

Many probably heard that a real electrician is not one that is not afraid of electricity, but one that is able to avoid direct contact with electricity. According to statistics, from electric shock, most often die electricians with experience of ten years or more. It is at this age that a sense of danger is dulled. Some experienced electricians test the presence of electricity by touch, yes, it is by touch. But why risk your own life when there are devices showing the presence of voltage?

There are a lot of devices showing the presence of voltage - from the simplest voltage indicator on a gas discharge lamp (neonka) to devices showing not only the presence of voltage but also many other parameters. In this article we will consider indicators and voltage indicators ...

Not so long ago, in our markets, on the Internet, in some print media and even on television, an advertisement for a miracle device appeared, which, according to advertisers, can save up to 30-35% of electricity. What kind of device is this? How is it arranged? And is it really true that he is able to save so much energy?

At about the same time, in different regions, these devices appeared under different names. Here are the approximate names of these devices: SberBox, smartbox, Energy Saver, Pover Saver, Saving-box, Economy, etc. According to manufacturers, and accordingly distributors, it is enough to simply plug the device into a power outlet, and it starts to work, that is, save our hard-earned money.

The cost of this device, depending on the region of distribution and the "generosity" of sellers, ranged from $ 10 to $ 70. So, we purchased one of these devices in order to try to deal with it ...

Electronic devices can be divided into two groups: mobile and stationary. The first of them use the so-called primary power sources, - galvanic batteries or accumulators that have a supply of electricity.

It immediately recalls mobile phones, cameras, remote controls and many other portable devices. In this case, rechargeable batteries and batteries are beyond competition, since there is simply nothing to replace them with. The only inconvenience, the cost of mobility is that the duration of such devices is limited by the capacity of the batteries, and, as a rule, is small. An exception to this rule are, perhaps, watches. Their energy consumption is very low, which is incorporated at the design stage, so the clock can go on a single battery for a whole year, or even more. Stationary devices, as a rule, receive power from secondary sources ...

Remember how in the cartoon “three from Prostokvashino”, Uncle Fedor’s mother said: “I’m so tired at work that I can’t even watch TV!” Apparently, this phrase is the answer to the question why all modern household equipment has infrared remote controls (RC). But, if you look, it all started much earlier.

The first work on remote control was carried out by the Germans in the late 30s of the twentieth century, even before the outbreak of World War II. The object of automation was a tube receiver. The control panel was a separate metal panel with buttons. Pressing the button triggered the actuator, - relay, electromagnet or motor. The connection between such a remote control and the receiver was made by a multicore cable, which still tied the listener to a specific place. Similar remotes were in the Soviet first-class tube TVs ...

Network interference as they arise. Network filter device, the purpose of its elements. Features of network filters.

Alternating current in a household network is sinusoidal. This means that changes in voltage, and, consequently, in current, occur along a sinusoid, that is, along a smooth arc oscillating symmetrically around the time axis. In one second, the voltage in the outlet changes its value from +310 to -310 volts fifty times. So, in theory, an AC network of 220 volts 50 hertz works.

However, if we look at the voltage waveform in our outlet, we will see that it is far from ideal. What is there a sinusoid !? Continuous peaks, impulses, shape distortions, amplitude changes, throws and jumps - this is what we will see. All this very spoils the picture and is able to disable household appliances ...

In this article, we will consider a device that is sold in electrical goods stores as a dimmer control. It's about a dimmer. The name "dimmer" comes from the English verb "to dim" - to darken, become dull. In other words, a dimmer can adjust the brightness of the lamp. Moreover, it is remarkable that the power consumption decreases proportionally.

The simplest dimmers have one rotary knob for adjustment, and two terminals for connection, and are used to adjust the brightness of incandescent and halogen lamps. Recently, dimmers have also appeared to adjust the brightness of fluorescent lamps.

Previously, rheostats whose power was not less than the load power were used to adjust the brightness of incandescent lamps. Moreover, when lowering the brightness, the remaining power was not saved in any way, but was dispersed useless ...

Switching devices or just contacts are very widely used in various electrical and radio equipment. In order to improve operational properties, first of all, the service life and reliability of the connection, magnetically controlled sealed contacts called reed switches were developed.

The first samples of such contacts appeared in the 30s of the last century, and the first magnetically controlled contact was invented in 1922 in St. Petersburg by Professor V. Kovalenkov, for which he was issued the USSR copyright certificate No. 466.

In fact, this was the very first magnetically controlled contact, only without a sealing shell. A similar contact was first placed in the sealing shell by an American engineer W.B.Ellwood only in 1936 ...