Do you know what an LED is and how it works? Is there only one type of LED or are there several? If there are several, what are the differences between them? Why don’t we see the infrared LED? Well, there are many doubts involving this subject and we will talk about all of them throughout this article, come on guys!
What is an LED?
LED is an acronym for Light Emitting Diode,! The LED is formed by two special semiconductors mounted together and when an electrical voltage is applied over them, they emit light in a process called electroluminescence!
What is the LED for?
LEDs can be used in lamps, lamps, traffic lights, headlights, and lanterns! The light that lights up on your cell phone when you receive a message is also an LED. The microwave display that shows the time is also formed by LEDs! We can say that there are many LED functionalities, mainly analyzing the advancement of technology.
Because it is a diode, the LED conducts electricity in one direction only. If you look at the image below, you can see that even the LED symbol is similar to that of the diode, the only change being that the LED has some arrows that indicate the luminosity coming out of it.
Another difference is that the LEDs have a much lower reverse voltage than the diodes. For you to have an idea, there are LEDs that do not support even 7V of reverse voltage, that is, when reaching this voltage, they already burn out! It is necessary to understand that as there are LEDs of different colors, there is also a difference in energy expenditure for each LED to work. Therefore, the voltage drop can vary widely, depending on the color of the LED.
You may not know it, but there are LEDs of various colors such as yellow, blue, white, orange, purple, violet, and even pink, but the most common are: red and green. There are also LEDs with more than one color in the same component. RGB LEDs can be controlled using each color individually, thus allowing the creation of a color effect.
There are also LEDs that emit invisible light to the human eye! In this group, there are the ultraviolet light LEDs and infrared LEDs. This type of LED is what is generally used in remote controls. But although it is not possible to view it with the naked eye, there is a very simple technique to be able to see this LED on the remote control, we will talk about it at the end of the article.
There are LEDs of various shapes and sizes, from miniature to SMD for soldering on plates, which can be a high-power LED, laser or even arranged to form the 7-segment displays. However, however efficient the LEDs are, they also produce heat!
Therefore, high brightness and higher power LEDs must have heat sinks or be cooled with fans! Even so, LED lamps are much more efficient than incandescent and fluorescent lamps, not to mention the durability that is also much greater.
How does LED work?
Each LED has a maximum operating current that can range from a few mA to many amps, depending on the power. One of the most common LEDs has a working current in the order of 20 to 30mA, that is, they burn out quickly when a very high current passes through it. Therefore, the LEDs must be switched on with some current limitations to prevent them from burning easily!
As the LED is a diode, it has a polarity, that is, there is a right side to connect it! When we look at the most common 3mm and 5mm LEDs that we easily find on the market, we can identify the polarity of these LEDs in several ways:
If you look closely at the LED, you can see that it has a small bevel on one side, as shown in the image below. This cut side is the cathode, which represents the negative side of the LED.
Another way to identify the polarity of the LED is through the size of the terminals, if you observe them, you will notice that one is larger than the other, in this case, the largest is the positive of the LED, as shown in the image below. But for that, it is necessary that you have the original terminals!
The third way to identify the polarity of the LED is by using a multimeter! To do this, place the multimeter on the diode measurement scale and then place each LED terminal on a probe of the multimeter. When the LED lights up, it means that the positive end of the multimeter is on the positive terminal of the LED, very simple, isn’t it?
If you want to be even better informed about the LEDs, we recommend this video from the World of Electrical that talks in detail and shows the practical examples of everything we talked about here in this article.
Before finalizing, will we explain how to see the LED on the remote control light up? Remembering that most LEDs on the remote controls emit light in the infrared spectrum, that is, invisible to the human eye! But if you point the remote control at the phone’s camera for example and press any button, you will be able to see the LED light-up perfectly on the camera screen.
Well, so this is what we had to talk about LED! If you have any questions, leave them in the comments and we will be happy to answer them.