What is Alternating Current?

Alternating current, (AC) is the most common form of electricity. AC became the standard due to the ease of distributing power over a long distance. With AC, a simple transformer outside your house steps the voltage down from the power company supply to a usable voltage in your home. Since it’s made up of no moving parts and some coils of wire, it’s a lot less expensive than using DC power as the standard delivery method.

In alternating current, the electrons do not move in just a single direction like they do in a DC circuit. Electrons will travel one path going from atom to atom, happy as can be, then turn around and hop backward atom to atom. They do this many times per second.

The rate at which alternating current reverses direction is called the frequency, and we express this in Hertz. Canada and the US are at 60 Hz whereas Europe is 50 Hz.

Example: It often helps compare the back and forth flow of alternating current to water in a piping system.

With the shaft fully forward, water is pushed in one direction. Water will start to move in this direction as the shaft begins to push outwards from the opposite direction.

As the shaft starts to pull in, water alternates direction and flows the opposite way. Now visualize this taking place 60 times a second.

Regardless of what direction of flow, water still flows throughout the whole piping system.

Each time the shaft in the piping above is fully outwards or fully inwards would be the peaks of the positive and negative sine wave.