AC electricity 06/14/16
“What is AC electricity?”
When one first starts to learn about the basic concepts of electricity and circuitry, they are first introduced to the conceptually easier and more primitive DC electricity.However, the most commonly used form of electricity for power transmissions in the modern age is known as AC electricity.
A generator for AC electricity works as follows. A shaft that contains magnetic materials is encass in series of windings. When the generator turns, the electromagnetic interactions between all of the materials will induce a voltage that alternates with time (hence the name Alternating current).
However, what makes AC power vital for long distance transportation is the transformer. Before AC, there was a problem, households require a lower voltage for safety purposes, but transferring low voltage over a long distance is inefficient due to the IR power loss, or the fact that the higher the current, the more energy will be dissipated over a long distance. But with the introduction of a transformer, this dilemma can be solved. Since AC currents are constantly changing, they produce magnetic fields around their paths. If one is to place a ring of loops near this magnetic field connected to a different circuit, then another current can be induced. What is particularly fascinating about transformers is that both circuits can have different voltages! The way that this works is that the value for magnetic flux will be different depending on the number of loops, so if the “receiving” side has more loops, the transformer will be a step up transformer and the other side will have a higher voltage, while the reverse is true for one with less wires (“step down” transformers). Therefore, the voltage for power transmission can be extremely high and can “step down” once it becomes close to a user’s home.