The term “direct current” has several types of definitions, and each of them deserves special attention. Most often, this concept is called an electric current, which has properties, directions and parameters that are unchanged from time to time. The existence of direct current is only possible in a closed circuit. This is due to the need to maintain a constant voltage, which is fundamental for this phenomenon. Despite various direct current sources, this definition always remains unchanged.
Direct current has a number of sources that are actively used in everyday life. The main ones are electric machine generators. Photocells, galvanic cells and thermoelements also serve as sources. The simplest type of direct current source can be called batteries (galvanic cells). In this case, direct current has a distinctive feature - the possibility of its multiple use, which makes such elements quite useful and cheap in everyday use. Agree, if every time you buy ordinary batteries on the camera, then the cost of photographs will increase significantly. This process can be achieved due to the property of reversibility of chemical reactions.
Electric machines and DC generators are electromechanical DC sources. DC power supply - the conversion of mechanical current into electric current. Various electrical equipment of cars and other vehicles is based on this. And on the same basis is the production of electricity by alternative methods - wind and hydro.
There are several types of DC / DC converters. The most common option is a rectifier, which is most often used in devices operating from an electrical network. Rectifiers are classified depending on the power, on the main rectification circuit, depending on the number of phases that are used in its operation. Also, DC amplifiers are used with them. In addition, classification options are possible for controlling the output parameters, for the presence of stabilization devices. It is almost impossible to list all possible classification options. But, one way or another, almost all of them are present in our houses and apartments, since without them it is almost impossible to use modern equipment.
Direct current is mainly used in the work of various equipment. The power source of almost all electronic circuits is precisely the electric current. For the existence of direct current, the presence of two mandatory conditions is sufficient - free electric charges and electric field.
In today's world, electricity is mainly generated by special power plants. This happens solely on the basis of technical and economic considerations. Thanks to the operation of power plants, direct current is distributed between numerous receivers that consume AC, not DC power. And only upon reaching a specific destination, the alternating current is converted to direct current, thanks to simple devices. Another area of application of direct current in the modern world is railways. Many models of electric locomotives work mainly due to the consumption of electric current.
As you can see, from all of the above, we can conclude that direct current reliably took leading places in the process of human life. It’s hard to imagine what will happen to humanity if electricity and direct current disappear overnight!