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LED FAQ: What’s Behind the Bulbs?

SEPCO 8/22/17 10:00 AM
LED Edison Bulb

LED Edison Light Bulb


The LED was first documented in 1962, but has become popular in recent years for a multitude of reasons. It’s unique construction and relatively low environmental impact make it extremely useful in situations from the domestic to the industrial. LEDs come in a wide range of sizes and colors, so the applications are infinite. Understanding how an LED works can be tricky, but when you abandon the jargon, it can be understood relatively easily. If you’re considering using LEDs for a lighting project, understanding how the bulbs work can help you conceptualize and install whatever it is you’re planning. This guide will introduce the science of LEDs, and explain their many applications and benefits.


How do lightbulbs work?

LEDs are different from other types of lightbulbs in several ways. Incandescent bulbs, which are what you picture when you think of a classic lightbulb, use a heated metal filament to emit light. In this case, the light is generated with heat. Light is just energy, and energy can be generated and emitted as many things, like heat, sound, and light. Using heat to create light is effective, but is less safe in some applications, and often less energy efficient. CFL bulbs are another type of lightbulb that is more energy efficient, also known as fluorescent bulbs. These bulbs electrically ‘excite’ argon gas and mercury inside the bulb so it puts off light, and a special white coating on the outside turns this light into visible white light, which is why CFL bulbs emit a brighter, harsher light than incandescent bulbs.


How is an LED unique?

An LED, however, uses energy differently than either of these types of bulbs. LED stands for Light Emitting Diode, which means that there is a semiconductor chip inside the bulb that controls the light that is cast when it is turned on. The light is cast when electrons, the negatively charged parts of atoms, are manipulated into giving off energy, which is emitted as light. When electrons ‘change phase’, they move up or down in terms of how much energy they are holding. This phase change causes photons, or light particles, to be cast off to shed energy. This is how an LED works to make light that we can see when we look at it.


How does an LED make these electrons shed light?

The electrons are forced to change phase by trapping them in between a positive and negative area. This is called the p-n junction, and is essentially a sandwich of positive and negative diodes, one with lots of electrons and one with not enough electrons, or ‘holes’ that need filling. These holes aren’t literal holes, they’re just areas with a small positive charge that seek a negatively charged electron to balance them out. In between the diodes is a neutral area that can hold a certain amount of energy before it overflows and the extra electrons move into the holes to try to even out the balance. When they move into the holes, however, they have to give up energy, which is cast off as light.


How can LEDs be used?

LEDs are in everything from your TV remote to your traffic lights. Because LEDs can be made in any size and color, they can create stunning visual displays. When the wavelengths of light that the LED puts off are altered, they can change color instantly. Some LEDs are used for infrared communication, like the ones in your remote. LEDs last much longer than other bulbs, and can be repaired much more easily. They also generate far less heat, making them safer for industrial use. While LED bulbs can be more expensive upfront, they need to be replaced much less frequently, pose much less of a risk, and take up less energy to use, so they quickly pay for themselves. And, with new solar technology, LEDs can be charged by the sun, which means you don’t have to pay for the electricity they do use.


If you’re looking at a new lighting project, LEDs might be the right choice for you. Now that you understand how they operate, you can start to imagine the infinite number of ways you can use LEDs. Whether you’re lighting a backyard patio or an Olympic swimming pool, see if LEDs can be used to make your project safer, more efficient, and less expensive.


Author Bio: Now working as a writer after becoming a mom, Jackie was previously working in the finance sector but decided to spend more time with her family. When she's not writing, she volunteers for a number of local mental health charities and also has a menagerie of pets to look after. 


Photo by Daniil Kuželev on Unsplash

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