Before entering fully into establishing the meaning of the term direct current, we are going to discover the etymological origin of the two words that give it its name:
-Current derives from Latin, specifically from "curren, currentis" which can be translated as "he who runs." It is the result of the sum of two clearly delimited components: the verb "currere", which means "to run", and the suffix "-nte", which is used to indicate "agent".
-Continua also derives from Latin, in its case from "continuus", which can be translated as "that lasts without interruption." It was formed from the sum of three elements: the prefix «con-«, which is synonymous with «together»; the verb "tenere", which means "to retain", and the suffix "-uo".
Direct current is the electric current that, while flowing, maintains the same direction. In this way it differs from alternating current , which periodically changes its direction.
It should be noted that electric current is the flow of charges through a conductor (a material that, due to its characteristics, facilitates the passage of electricity ). Electric charge, for its part, is a physical property possessed by particles such as electrons and protons, manifested by the forces of attraction and rejection that exist between them.
When the flow of electric current through a conductor does not change direction, it is a direct current. This means that, regardless of the time that passes, the direction of current flow does not vary: electric charges always flow in the same direction.
It is important to keep in mind that direct current (abbreviated as CC for its acronym, or as DC for the English expression direct current ) is not necessarily constant in terms of its intensity . An electric battery discharges and loses intensity, even when it has direct current because it maintains the same polarity.
With direct current, in short, the subatomic particles always move in the same direction, from the positive pole to the negative pole. If you want to transform alternating current into direct current, you can use the element known as a rectifier , which can be full wave or half wave.
In general, equipment that uses direct current does not have protection against a change in polarity. That is why it is key to respect the positive and negative poles when using batteries , for example.
Other data of interest about direct current are the following:
-It can also be called galvanic current.
-The first commercial electrical network , developed by Thomas Edison at the end of the 19th century, was known to use direct current.
-The transformation of direct current into alternating current is really complex but not the other way around.
-As a general rule, direct current is used in applications where a low voltage is needed. This can happen, for example, in systems where energy is produced by photovoltaic cells and even batteries.
-Currently, unlike centuries, alternating current is what is most used in transportation networks due to the advantages it brings.