# What is alternating current?

The alternating current is a type of electrical current that is characterized by change over time, either in intensity or direction at regular intervals.

The voltage varies between maximum and minimum values cyclically, the value of positive voltage is half the time (semicicle semiperíode positive or positive) and the other half negative. This means that half the time the current flows in one direction, the other half the time the other way.

The most common way to curl follows a trigonometric function sine type, since it is the most efficient and practical to produce electricity using alternators. However there are some applications you use other waveforms, such as triangular wave or square wave.

Generally the electric current is distributed in the form of alternating current at 50 Hz (50 updates per second).

Last review: March 15, 2017

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