Telexplainer is a technical and business blog about telecommunications and IT networking developments.
Also see current, voltage, and direct current. In electricity, alternating current (AC) occurs when charge carriers in a conductor or semiconductor periodically reverse their direction of movement. Household utility current in most countries is AC with a frequency of 60 hertz (60 complete cycles per second), although in some countries it is 50 Hz. The radio-frequency (RF) current in antennas and transmission lines is another example of AC. An AC waveform can be sinusoidal, square, or sawtooth-shaped. Some AC waveforms are irregular or complicated. An example of sine-wave AC is common household utility current (in the ideal case).
The power to the wires alternates in polarity and varies in potential from 0 - 170 volts (120 volts RMS) depending at which point in the generation cycle you analyze. At one point in time, the white wire will be at negative with reference to the black wire while 180Â° later in the cycle the opposite is true.he frequency of alternating current is 50 or 60 Hz, varying by country, meaning that this equipotential occurs 100 or 120 times per second, respectively. In the US, national standards call for the hot side of the line to be a black wire, or in the case of 120-240 VAC, the second hot wire (2nd phase) is to be red.