Introduction to Alternating Current
Alternating current refers to the current whose current direction changes periodically with time, and the average current in a cycle is zero. Unlike direct current, its direction changes with time, and direct current does not change periodically.
Usually the alternating current (AC) waveform is sinusoidal. Alternating current can effectively transmit power. But in fact there are other waveforms applied, such as triangular waves and square waves. The mains electricity used in life is alternating current with a sinusoidal waveform.