In recent years, from liquid crystal displays backlit by light-emitting diodes to desk lamps illuminated by them, this new type of lighting is increasingly appearing in our lives. So, what are the advantages of light-emitting diodes compared with traditional lighting methods.

How to provide us with lighting?

Incandescent: Before we look at how light-emitting diodes work and why they are more energy efficient, let's take a look at how a traditional incandescent light bulb, commonly known as a light bulb, makes light.

You might be surprised if I told you that everything around us glows. Yes, common sense tells us that only the stars in the sky can emit light, and even the moon is reflected light; apart from lamps, candles, etc., have you not seen other objects that are also emitting light?

Scientists tell us that any object, as long as its temperature is higher than absolute zero, will emit energy to the outside world in the form of electromagnetic waves all the time, which is called thermal radiation. The wavelength of electromagnetic waves ranges from thousands of kilometers to less than 1 nanometer, spanning a huge range, but only a narrow section of 400-800 nanometers can be perceived by our eyes, which is commonly referred to as visible light. So we can say that all objects, including ourselves, emit light.

However, the electromagnetic waves emitted by an object do not cover all the wavelengths uniformly, but are mainly concentrated around a certain wavelength, and the length of this wavelength is inversely proportional to the temperature of the object. For objects with a temperature near room temperature, the electromagnetic waves they emit are mainly concentrated in infrared rays with longer wavelengths than visible light, so the proportion of visible light is very small. That's why we can't see these objects glowing.

As the temperature of an object increases step by step, its thermal radiation will not only become more intense, but also the emitted electromagnetic waves will gradually become dominated by visible light, so these objects that were originally invisible and luminous will become brighter. For example, when the electric furnace wire is heated to hundreds of degrees Celsius, it will turn red, because the temperature rises so that the red light replaces the infrared light and occupies a dominant position in the heat radiation. If the temperature continues to rise to several thousand degrees Celsius, a large amount of light of yellow, green, blue and other colors with shorter wavelengths in visible light will also be released. Visible light of different wavelengths is mixed together, and we see white light similar to sunlight, which is the phenomenon of incandescence.

Before the appearance of incandescent lamps, people burned firewood, kerosene or candles for lighting. In fact, they were also using incandescent phenomena, but at this time they used the high temperature generated by chemical reactions; while incandescent lamps heated tungsten wires to Above 2000 degrees Celsius, thus producing a large amount of visible light.

From the perspective of energy conversion, when an incandescent lamp emits light, a large amount of electric energy will be converted into heat energy, and only a very small part can be converted into useful light energy. LED lights convert electrical energy directly into light energy. The energy conversion of incandescent lamps mainly generates heat, and then emits light. LED lamps mainly emit light, and then generate heat. Because of the small size, low current, low power consumption, long life, environmental protection and energy saving of LED lights, LED lights are currently used more.