Sponsors:
One of the hardest concepts people have to grasp when it comes to electricity is Direct Current (DC) and Alternating Current (AC).
Here’s my take on this…
The main distinguishing feature between DC and AC are the positive and negative nodes. For DC, the positive and negative ends are always constant and the same. So electricity only flows one way, all the time.
As for AC, the ends can be reversed or “alternates”. The number of times it alternates is different for some countries. For the US it is 60 times per second while in Europe it alternates 50 times per second. Therefore, what you get from a US wall socket is 120-Volts, 60-cycle AC power.
The big advantage of alternating currents is its ability to transfer large amounts of electricity over long distances by regulating the voltage with a transformer.
For moving 1000 watts of power over a 1km distance, we can…
using the W=VxI
- either move 1000amps of current with 1volt over a kilometer
- 1000volts and 1amp over the same distance.
The first one would require a wire diameter that is extremely thick to be able to carry 1000amps. While the second one only requires a thin wire.
The savings are obvious and this is exactly what power companies do. From the power plant they jack up the voltage extremely high, then transfer it through power lines and because high voltage is extremely dangerous, when it nears a load destination a transformer brings the voltage back down for residential, commercial or industrial use.
And that is how power is transferred from the power plants to your home.
