What is an Alternating Current?

Alternating current refers to the current whose current direction changes periodically with time, and the average current in a period is zero. Unlike direct current, its direction changes over time, while direct current does not change periodically.

When found

The value of AC at a certain moment is called

according to

The AC power phases currently used in various countries are mainly single-phase and three-phase. ^[4]

"Direct Current" (DC for short), also known as "Constant Current". Constant current is a type of direct current. It is a direct current with the same size and direction. It was discovered by Edison. In 1747, Franklin in the United States experimentally proposed the law of conservation of charge and defined the terms positive and negative. ^[2]

Constant current means that the size (high and low voltage) and direction (positive and negative) do not change with time (relative range), such as dry batteries. Pulsating direct current means that the direction (positive and negative) does not change, but the size changes with time. For example: 50Hz AC is rectified by a diode to obtain a typical pulsating DC. Half-wave rectification is 50Hz pulsating DC Full-wave or bridge rectification can obtain 100Hz pulsating DC power. They only become smooth DC power after filtering (using inductor or capacitor). Of course, there is still a pulsating component (called ripple coefficient), depending on the size of the filter circuit. Filter effect. ^[2]