Electric Current Definition (AC or DC)

Do you remember the electric current definition you learned in school? Or the difference between direct current (DC) and alternating current (AC)? Probably not as I didn't understand the difference before writing a recent article explaining how solar energy works.

Let's start with electricty, defined as the physical presence and flow of electric charge. Electric current is the movement of electrically charged particles which we use in our houses for lighting, appliances, air conditioning, entertainment and so much more.

You might connect the light bulb with Thomas Edison but he didn't invent the first light bulb or electricty. What he did create was the:

First commercially practical, incandescent electric light bulb.
First economically viable system of centrally generating and distributing electricity, which he did in New York City.

Electric Current Definition for Direct Current

Thomas Edison used a one way circuit (like a one way street) to deliver electricty to his light bulbs, and that system is known as direct current (DC). He patented direct current but ran into problems distributing electricity over long distances. That's because transmitting electricty at higher voltages is more efficient and it's difficult to change the voltage of DC electricity.

Electric Current Definition for Alternating Current

That's when Nikola Tesla's alternating current (AC) solved the problem because it can be converted to different voltages relatively easily using a transformer. That's because alternating current reverses direction continually (60 times per second in the US) and different transformers can increase or decrease the voltage.

The tug of war between these two approaches (DC versus AC) was known as the battle of the currents. “General Electric bid to electrify the fair using Edison’s direct current for $554,000, but lost to George Westinghouse, who said he could power the fair for only $399,000 using Tesla’s alternating current.” according to Energy.gov.

Today's power grids in the US and throughout the world, all use AC electricity to distribute power through their network of transformers.

Want to learn more about electricity and how much you're using at your house? Here are a few ideas and you might also want to learn about Energy Vampires: Find & Tame Them.

Electricity Demystified, Learn how your home is powered Home Efficiency Tips and Tricks for the DIY Homeowner Kill A Watt EZ P4460) to monitor electricity usage, one device at a time