The difference between alternating current and direct current

Electric current is an ordered movement of electric charges.

Electricity has different properties and parameters, including the current form. If the shape of the electric current is straight (the voltage is a constant value) we are talking about direct current. For example, a battery is a source of direct current. If the form of the electric current is different to the right (the value of the voltage is variable in time) we are talking about alternative current.

AC is mainly characterized by two dimensions (shape and frequency):
* It has a sinusoidal shape (symmetrical, harmonic shape). This is the ideal way in which electricity is produced from the national grid power supply.
* The voltage oscillation frequency is between the frequency of 50 Hz (line frequency) to various frequencies of GHz (cell phone, radio, etc.)

In the beginning, both types of current were used to transmit electricity. Over time, it was shown that AC can carry power over longer distances without any loss. Also, the AC voltage can be changed easily by using a transformer. It is very effective in transporting power over long distances at a very high voltage, but for use inside houses and plants, a lower voltage is needed for safety. A series of transformers can adjust the voltage as needed.

For some users it is irrelevant whether AC or DC is used. For example, electric lighting uses both types of current, but some applications must use a particular type of current.

Direct current is used in low voltage applications. Batteries and solar systems only produce direct current. Most electronic devices also run on direct current. If these devices must be powered by household alternative current, you must install an adapter. This adapter converts alternating current into direct current, avoiding damaging electronic devices.