Various definitions

Within electrical engineering, the appellation DC is acclimated to accredit to ability systems that use alone one polarity of voltage or current, and to accredit to the constant, zero-frequency, or boring capricious bounded beggarly amount of a voltage or current.[2] For example, the voltage beyond a DC voltage antecedent is connected as is the accepted through a DC accepted source. The DC band-aid of an electric ambit is the band-aid area all voltages and currents are constant. It can be apparent that any anchored voltage or accepted waveform can be addle into a sum of a DC basic and a zero-mean time-varying component; the DC basic is authentic to be the accepted value, or the boilerplate amount of the voltage or accepted over all time.

Although DC stands for "direct current", DC generally refers to "constant polarity". Under this definition, DC voltages can alter in time, as apparent in the raw achievement of a rectifier or the clashing articulation arresting on a blast line.

Some forms of DC (such as that produced by a voltage regulator) accept about no variations in voltage, but may still accept variations in achievement ability and current.