The LED is a small electronic component that emits light.
Most likely, you will work a lot with LEDs, when you start your journey in the field of electronics. They are cheap, easy to use, and good, for example, to obtain a specific indication, if your circuit is working properly or not.
LED stands for light-emitting diode. This type of diode that emits light when current flows therethrough.
Commonly used to display states in electronics. For example, to show that the circuit is energized.
We can see these components are everywhere! In our laptop on our mobile phone, on our camera in our car, and so on.
How does the LED light?
To understand the operation of the LED, you need to understand the physics of semiconductors. Simply put, similar to LED a standard diodeBut with the addition of a phenomenon called electroluminescence.
Connecting LEDs
The LED has two terminals, which are called the anode and the cathode.
The anode - the longest leg. This contact, which you connect to the positive. Cathode - a contact that you connect to a minus. They must be properly connected to the LED work.
EXAMPLE circuits with LED
Typically, LEDs need about 2 volts and about 15-20 mA. But it depends on type LED.
In the diagram you can see that the LED is always series resistor.
If you miss too much current through the LED, it is very strongly heats up and burns. That's why using a resistor - in order to control how much current flows through the LED. I call it a current-limiting resistor.