Inverter: what it is and how the device works, history of appearance and classification

One of the most important scientific advances in the 19th century was the establishment of electricity. Thanks to this, a person has the opportunity to perform any work after sunset, which was previously impossible. Today there are two types of current - direct and alternating, but specialists have always been interested in the possibility of converting one into another, which led to the emergence of an inverter. What it is and how it works can be found in the relevant literature.

History of origin

In the late 80s of the XIX century, Thomas Edison received direct current in his laboratory and decided to share this discovery with everyone. The scientist argued that such a source is much better than alternating current for powering devices.

The variable current source was discovered a few years earlier by the scientist from Serbia Nikola Tesla and was actively spreading the idea among all his fans. Edison became his competitor and tried to convince people that alternating current is dangerous to people and ineffective for powering electrical appliances.

Despite all the arguments, Nikola Tesla had a lot of fans, his technique was actively used, and at that time Edison lost in the competition. Although alternating current is still needed today, direct current is considered the best option for powering electrical appliances.

It is worth noting that many devices designed to work with alternating current emit direct current. This leads to the fact that when starting such a device, a person will need an additional device for converting direct current into alternating current, that is, an inverter.

Types of electricity

Most of the teachers who provide information on electricity to students speak mostly about direct current (DC). It is a stream of electrons that follow each other at a certain distance. The most popular analogy from experienced teachers is the comparison of a stream with ants walking in a column carrying ordinary dry leaves.

This view is rather general, but the main idea is correct. The circuit resembles a solid electrical looppowering an ordinary flashlight. However, in large household appliances, electricity works differently. Wall-mounted sockets supply the appliances with an alternating current (AC) power source. In it, electricity is switched at a high speed of 50-60 times per second, that is, the frequency of such switching is 50-60 Hz.

An ordinary person who does not have knowledge in the field of electronics is not entirely clear how such a current feeds devices, if it constantly changes the direction of its movement. However, the answer to this question is simple. For example, you can take a conventional wall lamp powered by an AC source. When you plug it into an outlet, the electrons begin to actively move, change places and change the direction of movement. The whole process happens very quickly, so heat is generated in the wires.

It is this heat that will pass into the lamp, leading to its glow. Alternating current is just as efficient at powering fixtures as direct current, but the electrons in it move in place.

General information about the device

The greatest discovery of Nikola Tesla today is used by humanity everywhere. Most of the fixtures in every home are designed to operate on DC power, but AC power comes from outlets. This is why a special device or rectifier is almost always required to convert AC to DC.

The inverter, on the other hand, performs the exact opposite function. You can see how it works using an ordinary flashlight as an example. The device is small and powered by a built-in battery, which becomes a constant current source. If you remove it from the fixture, turn it over with the other pole and reinstall it, there will be no noticeable difference in operation or in the quality of lighting. However, electricity will flow differently.

This process can be compared to a mechanical converter, when human hands rotate the battery at a speed of 50-60 times per second. Of course, devices that can be purchased in specialized stores work a little differently. Magnetic switches are used to constantly change the direction of motion of the electrons. However, such a design is only for devices of a mechanical type.

Electronic inverters change direction smoothly, excluding sudden voltage drops. The second type is considered a preferable option, since constant voltage surges negatively affect the functioning of some electrical appliances. The design of such inverters is equipped with special inductors and capacitors. These parts soften the flow of energy at the inlet and outlet, due to which a smooth power supply for electrical appliances is formed.

In some cases, inverters are used for transformers in order to convert an AC source to a higher or lower frequency, depending on the needs of a particular consumer. It should be noted that the output power is always less than the input power. This is necessary for the normal functioning of the devices. Any transformer or inverter cannot generate more energy than it consumes, since some of it is lost.

Principle of operation

The inverter operates according to a simple principle, which can be understood if you give a specific example. A conventional battery works primitively and produces a constant flow of current that does not change its direction. If a switch is added to this structure, which at the output will change the direction of movement of electrons, then AC will be supplied to the device. To make it correct, the switch must work properly and operate at least 50 times within a second. There are about 3000 changes in the flow of electrons per minute.

A mechanical inverter works in a slightly different way and, using special magnets, also quickly changes the direction of the current. The principle of its functioning resembles a doorbell. When the button is pressed, a person acts on a spring, which gives a signal to change the power and flow of electricity. When released, everything returns to its original position. The device is also equipped with a special controller that performs other functions:

• voltage regulation in the device;
• synchronization of the switching frequency;
• providing protection against overloads and breakdowns.

Thanks to this, even the mechanical model of the device allows large electrical appliances to work smoothly.

Device classification

There are many models of inverters. They can be massive and equipped with special batteries. Portable models are available that are small in size and are used for different purposes. The devices are also divided according to the power they consume and produce. This parameter is considered the main one when choosing, especially if a high indicator is required, for example, in production.

It should be noted that even the most powerful inverters are not designed for long-term operation at maximum performance. Depending on the principle of operation, the devices are divided into the following:

• addicts that work only on the network;
• autonomous, equipped with a battery;
• voltage and current inverters.

Stand-alone models are usually used for short-term operation and do not depend on the power source. Individual devices are specially designed for permanent connection to the network. Sometimes devices are equipped with solar panels.

Each of the options has its own advantages. For example, stand-alone devices are suitable for any device and can help out in a difficult situation. Solar energy saves energy, and addicts do not need recharging or other conditions to function. At night, the solar battery is inappropriate and will not be able to serve the owner, so such models are rarely chosen.

There are also universal devices that can operate on the network and offline, but not simultaneously. The disadvantage of such devices will be their large size, since in order to ensure functioning in two modes, it is necessary to equip the unit with additional parts.

The devices, which were installed before 1970, used special mercury-arc valves in their work. Modern models are usually solid and are considered to be more efficient and safer.

Welding inverters

Separately, it is worth highlighting special inverters that can significantly increase efficiency. work of the welding machine and quickly connect two metal parts without effort and make a structure reliable. These inverters have many advantages:

1. They are characterized by high power and performance.
2. Reliability and durability of welded seams.
3. The ability to choose a compact model and move it to the place where the person will work.
4. High efficiency of almost 90%. This figure is much higher than that of conventional transformers.
5. Moderate consumption of electrical energy and efficiency.
6. During the operation of the welding machine, metal spatter is separated in a smaller amount, which saves not only electricity.
7. The ability to regulate the supply of current, making it smooth.
8. A welder can perform metal work even if he does not have much experience in this area.

The versatility of the device allows it to be used in different areas, and the ability to choose the best model in terms of price-quality ratio is considered one of the important advantages.

Popular varieties

Before choosing a suitable device, it is recommended that you familiarize yourself with its varieties and purpose. There are models used only for welding, and there are devices for cutting metal. It is also worth noting that devices for professional use are produced with large sizes.

For home use, you should choose non-professional or semi-professional inverters. The latter combine more functions. When choosing, consider the input voltage. The standard indicator is 220 V, but there are models that are designed to operate from a source with a voltage of 380 V.

The ease of ignition of the device can fluctuate between 40-90 V. The higher this indicator, the easier it is for a specialist to work. If a person intends to use the device at maximum voltage for a long time, it is recommended to pay attention to the numbers indicated by the manufacturer in the technical passport. A good figure is 70% or more.

If the owner knows he will be working with thin metal, it is advisable to pay attention to the lower limit of the outgoing current. This figure should not exceed 10 A. Otherwise, there is a risk that the beginner will ruin the material. Professionals rarely have such problems, so they can use any device.

Many models have additional features. For example, a hot start increases stress for a short period, which makes work easier. For those new to the inverter, there is an anti-stick mode. It prevents the electrode from being welded to the edge, which often happens if a person does not have much experience in this matter. Arc Forcing is an additional function that prevents sticking of the electrode in the event of a large drop of molten metal separating from it.

The presence of such modes greatly facilitates work for a beginner and a professional, eliminates unpleasant and emergency situations.

An inverter is a universal device that allows you to make the work of household, industrial and other devices smoother and more efficient. When choosing and using a device, you should follow the recommendations that will facilitate the process.