ac/dc, tinggal kenangan.

In 1887 direct current (DC) was king. At that time there were 121 Edison power stations scattered across the United States delivering DC electricity to its customers. But DC had a great limitation -- namely, that power plants could only send DC electricity about a mile before the electricity began to lose power. So when George Westinghouse introduced his system based on high-voltage alternating current (AC), which could carry electricity hundreds of miles with little loss of power, people naturally took notice. A "battle of the currents" ensued. In the end, Westinghouse's AC prevailed.

But this special feature isn't about the two electrical systems and how they worked. Rather, it's a simple explanation that shows the difference between AC and DC.
To find out more about alternating and direct current, what exactly an electric current is, and two ways that the currents can be produced, check out the interaction to the left and the pages that follow.
DC (Direct Current)

OFF

AC (Alternating Current)

Imagine that you're holding a garden hose -- one with no nozzle attached. With nothing to obstruct the water, it pours out of the hose's end freely. But if you place your thumb over the end of the hose, the water's going to squirt out. The reason it does is because of the resistance created by your thumb.

It works much the same way for a light bulb. Electrons move relatively freely through the wire, then they come to the bulb's filament, which resists the flow of electrons.

The electrons can get through, but not as easily as they can through the wire. The work done overcoming the resistance causes the filament to heat up and to give off light.



From : American Experience




Ayo kamu pasti bisa ngikutin jejak para pendahulu! Amien.