Meet the Family
We want to introduce you to the Green Family. They have been nice enough to let us record their conversations during dinner. Every evening their family discusses a wide variety of subjects from planting trees to reducing waste. For them, taking care of the environment is very important.
LED: The Next Generation Bulb
Hey Dad, what are LEDs? Why are they different from regular bulbs?
You know about LEDs? That’s fantastic! LED stands for Light Emitting Diode. Its like a high tech light bulb.
I think I’ve heard that word before.
LEDs have the characteristic which allows them to light up when electric current flows through them. That means LEDs can transform electricity into light. Like a light bulb. Do you want to know how?
OK, then. LEDs are made of “semi-conductor” materials. And semi-conductor materials can partially conduct electricity.
Cool! Solar modules are made of a semi-conductor material too. It’s called Silicon. Right?
Yes! LEDs have two types of semi-conductor material, a “P-type” and “N-type.” When you run the electricity through a LED, the current flows from the P-side to the N-side. This is the only direction the electricity can flow. As the electrons move, they release energy in the form of photons … which is light!
So LEDs work in the opposite way from Solar. With Solar, photons (light) from the sun are turned into electricity. However with LEDs, electricity is turned into photons (light). OK, I get it now. My friend said LEDs are also good for the environment, right?
Yes. Very good. First of all, LEDs have a very long life. Normal incandescent light has a life about 1000 to 2000 hours, but a LED can last for about 40,000 hours.
Wow!!! That’s like forever...
That means you don’t have to replace the light bulbs as often as you did before. Also, the electric energy consumed by LED to get the same brightness is about 1/5 to 1/10 of the regular incandescent lights. And if you use less energy…
You can reduce CO2 emission!
That’s right. In addition, LEDs are very light and small, so it doesn’t take much material to produce them. Because LEDs do not use lead that is often used for regular fluorescent lights, you can also avoid polluting the environment. LED technology is now expected to be the next generation light that helps conserve environment.
LEDs are great. I want to have them in my house…
I think you’ve already got them.
This technology is already used in many places. For example, they are used for streetlights, just like you noticed, and traffic lights.
Yes. LED lights are very bright but don’t give off lots of heat. Plus, there good for the environment. In the United States, there are more than 4.5 million traffic signals with LEDs! Other examples of places we use LEDs are cars. Many car manufacturers are using LED for backlights and break lamps. You can find LEDs everywhere from video game consoles to cell phones to holiday decorations. Can you guess where else you have LEDs?
Well… The lights for our Christmas tree! And lights in our clock… and our computer!
Good job! You see that there are many LEDs around us. And in the future there will be even more.
I can’t wait for my family to light up my little dog house with LEDs!