direct current

In a conductor such as an electric wire, this refers to a situation where electric current flows in only one direction and voltage is applied in only one direction. Usually, the voltage magnitude remains constant, but it may also vary in forms such as full-wave rectified waveform, half-wave rectified waveform, or pulsating waveform. Compared to alternating current, direct current has advantages such as efficient use of electric wire due to the absence of reactive power and skin effect. However, it also has disadvantages like difficulty in changing the magnitude of voltage or current. While alternating current is mainly used in power transmission and distribution circuits that handle large electrical power, direct current is mainly used in electronic circuits that handle very small power.