Some basics: direct current and alternating current. What are?

Electric current is the orderly flow of electric charges through a conductor. Current can be of two types: direct or alternating. In this article we will see what the difference is between these two current regimes, how they are generated, who discovered and theorized them and what their main uses are.

What is direct current

Direct current (DC or DC) is a current that has a constant direction and intensity over time. This means that the electric charges always move in the same direction, from the negative pole to the positive pole of the voltage source. Direct current is generated by devices that maintain a constant potential difference between the two poles, such as batteries, photovoltaic panels or dynamos. Direct current is used to power devices that require a stable and constant voltage, such as electronic circuits, watches, computers, portable household appliances, car electrical systems, etc.

What is alternating current

Alternating current (AC or AC) is a current that changes direction and intensity over time, following a sinusoidal pattern. This means that the electric charges move back and forth between the two poles of the voltage source, reversing direction periodically. Alternating current is generated by devices that produce a potential difference that varies over time, such as rotating electric generators that exploit mechanical energy or turbines in power plants. Alternating current is used to transmit electrical energy over long distances, as it allows the voltage level to be easily varied via transformers. Alternating current is also used to power devices that require variable voltage or that can adapt to different voltage levels, such as electric motors, fluorescent light bulbs, electrical appliances, etc.

Who discovered and theorized direct and alternating current

Direct current was first discovered by Alessandro Volta in 1800, when he invented the voltaic pile, the first direct current generator. Volta demonstrated that it was possible to produce a constant current by connecting disks of different metals separated by fabric soaked in saline solution. Volta was also the first to define the concept of potential difference between two points of a circuit.

Alternating current was later discovered by Michael Faraday in 1831, when he observed that moving a magnet inside a coil produced a current that varied over time. Faraday formulated the law of electromagnetic induction, which explains how an electromotive force is generated in a closed circuit when the magnetic flux passing through it varies.

The theory of alternating current was developed by James Clerk Maxwell in 1865, when he published his four fundamental equations of electromagnetism, which mathematically describe the behavior of electric and magnetic fields and their interactions. Maxwell proved that light is an electromagnetic wave and predicted the existence of other waves with different wavelengths and frequencies.

Conclusion

Direct current and alternating current are two different current regimes that have different characteristics, origins, discoverers and applications. Direct current has a constant direction and intensity over time and is generated by devices that maintain a constant potential difference. Alternating current changes direction and intensity over time following a sinusoidal trend and is generated by devices that produce a variable potential difference. Direct current was discovered by Volta and alternating current by Faraday, while the theory of electromagnetism was developed by Maxwell.

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The article Some basics: direct current and alternating current. What are? comes from Economic Scenarios .

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This is a machine translation of a post published on Scenari Economici at the URL https://scenarieconomici.it/un-po-di-basi-corrente-continua-e-corrente-alternata-cosa-sono/ on Wed, 04 Oct 2023 19:08:22 +0000.