Alternating Current

AC is the common form of electricity that we get in the United States when we plug an appliance into the wall.  It is an electrical current for which the current direction, or positive to negative flow (known as polarity), changes back and forth over a specified period of time. The frequency with which the current direction alternates is measured in cycles per second and is referred to as ‘hertz.’ In North America, the common frequency is 60 hertz, which indicates that the current direction or polarity changes back and forth 60 times per second.