How is AC and DC generated

AC and DC power: these are the differences

AC current: Abbreviation for Alternating Current

The abbreviation AC comes from English and stands for Alternating Current. AC power is therefore alternating current. This means that its charge carriers change their direction of movement periodically and in continuous repetition. AC current is measured at a frequency that indicates the number of reversals per second. In Europe, AC electricity has a frequency of 50 Hz (i.e. 50 reversals of the charge carriers) per second.

AC power covers general electricity supply - it comes from the wall socket. Thus, alternating current powers all devices in the house: from the refrigerator to the ceiling light. In contrast to DC current, AC current has the advantage that its voltage can be changed inexpensively. Power transmission over long distances is also much more efficient, as less energy is lost than with direct current.

DC current: Abbreviation for Direct Current

The abbreviation DC stands for Direct Current and is the equivalent of the German term DC. The voltage source of direct current is always the same polarity. This means that the electric current always flows constantly in the same direction. However, the voltage level does not always have to be the same: The voltage level can decrease in the course of a discharge.

DC power is mainly used in low-voltage technology: the best-known example of a direct current source is the battery. Batteries for laptops, smartphones and the like can only be charged with DC power. Before that is possible, however, a power supply unit that connects the device to the socket converts the electricity. The advantage of DC power is that it can be stored using rechargeable batteries and batteries - and this stored electrical energy enables the use of mobile devices in everyday life. In contrast to AC power, this is only possible with DC power.

A historical digression: How was AC-DC current discovered?

As for the differences in AC-DC current detection, there are several theories. The first discoverer of electricity could have been the English doctor William Gilbert, who first used the word "electricus" in 1600. It may also be the English scientist Thomas Browne who coined the word "electricity" a few years later. In 1752 Benjamin Franklin succeeded with his kite experiment to investigate the electrical charge of lightning - the later lightning rod was born. However, there is also evidence that the ancient Greeks knew about electricity.

Whoever is said to have been the first to know about electricity, it was always direct current (DC current). Alternating current (AC current) was only discovered in the 19th century - by the English physicist Michael Faraday. In 1831 he found out from a coil made of conductive wire that it generates electrical current by moving a magnet back and forth in the coil. Based on his resulting finding that the current changed direction when it again adjusted the direction of the magnet, the French instrument maker Antoine-Hippolyte Pixii built the first alternator a year later.

AC Current vs. DC Current: What's the Difference in Charging?

Back to the present: E-mobility also deals with the difference between AC and DC power. This is because it plays an important role when charging e-cars. This is the difference between AC and DC power in the charging station. Basically, e-cars only consume DC power - therefore the AC power from the grid has to be converted beforehand. If this conversion from AC current to DC current takes place via the on-board charger in the e-car, it is known as AC charging. If the conversion is done by a rectifier in the charging station, this is called DC charging.