How to make a DC from a DC? Which current is more dangerous - permanent or variable?

The use in everyday life of various electrical appliances and devices working with electricity, obliges us to have minimal knowledge of electrical engineering. This is knowledge that keeps us alive. Answers to questions about how to make a variable from DC, what voltage should be in the apartment and what current is dangerous, a modern person should know in order to avoid defeat and death from it.

Ways of obtaining electricity

Today it is impossible to imagine your life without electricity. Every day the entire population of our planet uses millions of watts of electricity to ensure normal life. But once again, including an electric kettle, a person does not think about what way it was necessary to do electricity, so that he could make himself a morning cup of fragrant coffee.

There are several ways to get electricity:

• From thermal energy;
• From the energy of water;
• From atomic (nuclear) energy;
• From wind energy;
• From solar energy, etc.

In order to understand the nature of the origin of electrical energy, let us consider several examples.

Electricity from wind power

An electric current is a directed movement of charged particles. The easiest way to get it is the energy of natural forces.

In this example, the wind energy. The natural phenomenon of the blower with different wind power people have learned to use for a long time. Tames the wind a simple windmill, equipped with a drive and connected to the generator. The generator generates electrical energy.

Excess current can be accumulated in batteries when the windmill is used constantly. The developed constant ecologically pure current in a life and manufacture is not applied.

Received and converted to alternating current, it goes for household use. The accumulated surplus electricity is stored in rechargeable batteries. In the absence of wind, electricity reserves stored in batteries are converted and supplied to human needs.

Electricity from water

Unfortunately, this kind of natural energy, which makes it possible to receive electricity, is not always available. Let's consider a method of obtaining electricity where there is a lot of water.

The simplest hydropower plant, made of wood on the principle of a mill, the size of which is about 1.5 meters, is able to provide electricity, used for heating, private farming. Such a powerless hydropower plant was made by the Russian inventor, native of Altai - Nikolai Lenev. He created a hydroelectric station, which can be carried by two adult men. All further actions are similar to obtaining electricity from the windmill.

Generate electricity and large power plants and hydroelectric power stations. For the industrial production of electricity, huge boilers are used to produce steam. The temperature of the steam reaches 800 degrees, and the pressure in the pipeline rises to 200 atmospheres. This superheated steam with a high temperature and huge pressure enters the turbine, which starts to rotate and produce a current.

The same thing happens in hydroelectric power plants. Only here the rotation occurs due to the high speed and volume of water falling from a huge height.

The designation of current and its use in everyday life

The DC current is denoted by DC. In English it is written as Direct Current. He does not change his properties and direction in the course of time. The frequency of the direct current is zero. Designate it on drawings and equipment with a straight short horizontal dash or two parallel dashes, one of which is dotted.

A constant current is used in the usual batteries and batteries used in a huge number of different types of devices, such as:

• Counting machines;
• Kids toys;
• Hearing Aids;
• Other mechanisms.

Every day they use a mobile phone. Charging it takes place through a power supply, a compact DC / AC converter, included in a household outlet.

Electrical appliances consume a variable single-phase current. Electrical appliances will work only with the connection of a transformer and a rectifier. Many manufacturers install a DC / AC converter directly into the unit itself. This greatly simplifies the operation of electrical equipment.

How to make a DC from a DC?

Above it was said that all batteries, batteries for flashlights, TV consoles have a constant current. To convert the current, there is a modern device called an inverter, it will easily make a variable DC current. Consider how this applies in everyday life.

It happens that when you are in a car, you need to urgently print a document on the copier. Xerox is available, the machine is working and, having included a cigarette lighter adapter on the inverter, it can connect to it a copier and print documents. The converter circuit is quite complicated, especially for people who have a remote understanding of the operation of electricity. Therefore, for safety reasons, it is better not to try to build an inverter on your own.

Alternating current and its properties

Flowing, alternating current for one second changes direction and value 50 times. The change in the current is its frequency. The frequency in hertz is indicated.

We have a current frequency of 50 hertz. In many countries, for example the USA, the frequency is 60 hertz. Also there is a three-phase and single-phase alternating current.

For household needs, electricity comes to 220 volts. This is the effective value of AC. But the current amplitude of the maximum value will be greater by the root of the two. That in the end will give 311 volts. That is, the actual voltage of the household network is 311 volts. To change the direct current to an alternating current transformers are used, in which different converter circuits are used.

Transmission of current through high-voltage lines

All electrical external networks carry alternating current of different voltage through their wires. It can range from 330,000 volts to 380 volts. Transmission is carried out only by alternating current. This method of transportation is the simplest and cheapest. How to make AC out of constant, has long been known. Putting the transformer in the right place, we get the necessary voltage and current.

Diagrams of converters

The simplest scheme for solving the problem of how to make a variable 220 V from a direct current does not exist. This can make a diode bridge. The DC / AC converter circuit has four powerful diodes in its composition. A bridge assembled from them creates a current flow in one direction. The bridge cuts the upper boundaries of the variable sinusoids. The diodes are assembled in series.

The second circuit of the AC converter is a parallel connection to the output from a bridge assembled from diodes, a capacitor or a filter that will smooth out and correct the dips between the peaks of the sinusoids.

It perfectly converts direct current to an inverter. Its scheme is complex. Used parts are not from the cheap order. Because the price of the inverter is rather big.

Which electric current is more dangerous - permanent or variable?

In everyday life, we are constantly confronted at work and at home with electrical appliances plugged into sockets. The current running from the electrical panel to the socket, single-phase variable. There are cases of electric shock. Safety measures and knowledge of electric shock are necessary.

What is the fundamental difference between falling under AC voltage and constant? There is a statistic that AC variable one-phase current is five times more dangerous than a constant AC current. Electric shock, regardless of its type, is in itself a negative fact.

Consequences from electric shock

Negligence in the handling of electrical appliances can, to put it mildly, have a negative impact on human health. Therefore, do not experiment with electricity, if there is no special skills.

The effect of current on a person depends on several factors:

• Resistance of the victim's body;
• Tension, under which man fell.
• From the strength of the current at the moment of human contact with electricity.

In view of all of the above, it can be said that the action of an alternating current is much more dangerous than a constant one. There are experimental data confirming the fact that in order to obtain an equal result in a lesion the force of a direct current must be four to five times higher than that of a variable current.

The very nature of alternating current adversely affects the work of the heart. When an electric shock occurs, involuntary contraction of the cardiac ventricles occurs. This can lead to its suspension. Especially dangerous is contact with stripped veins to people who have a heart stimulant.

At a constant current the frequency is absent. But high voltage and current can also lead to death. Getting out of contact with a constant electric current is easier than from under contact with a variable.

This small survey of the nature of the electric current, its transformation, should be useful to people far from electricity. Minimal knowledge of the origin and operation of electricity will help understand the essence of the work of ordinary household appliances, which are so necessary for a comfortable and peaceful life.