Introduction to LEDs
Discover how tiny chips create colorful light
Discover how tiny chips create colorful light
LED stands for Light Emitting Diode - a tiny electronic component that produces light when electricity flows through it.
Produces visible light - no heat like bulbs!
Releases photons when electrons move
Only allows current in one direction
The first visible LED was invented in 1962 and only glowed red. It took until 1994 to create a bright blue LED - a breakthrough that won the Nobel Prize!
Inside an LED, electrons jump between energy levels. When they drop down, they release energy as light!
High energy level where electrons can move freely through the material.
Lower energy level. When electrons fall here, they release a photon.
The energy difference determines the color of light produced!
LEDs are about 90% efficient - almost all electricity becomes light! Incandescent bulbs waste 90% as heat.
LEDs only work when connected the right way. The longer leg (anode) goes to positive, shorter leg (cathode) goes to negative.
If you connect an LED backwards, it won't light up - but it also won't break (unless the voltage is very high). It just blocks current!
Different LED materials produce different colors. Each color has a specific wavelength measured in nanometers (nm).
Blue/violet light has more energy. These LEDs need higher voltage to operate.
Red light has less energy. Red LEDs were the first invented because they're easiest to make.
White LEDs don't actually exist! "White" LEDs are blue LEDs with a yellow phosphor coating that mixes to appear white.
LEDs need current-limiting resistors to prevent burnout. Without one, too much current flows and destroys the LED!
Without a resistor, current spikes and the LED overheats, often burning out instantly!
Each LED color has a specific voltage drop. The resistor handles the rest.
Professional LED circuits use constant-current drivers instead of resistors. These are more efficient and keep brightness consistent!
You now understand how LEDs convert electricity into light, why polarity matters, how different colors work, and how to protect LEDs with resistors. These tiny lights power everything from phone screens to traffic signals!
LEDs emit light when electrons drop to a lower energy level, releasing photons.
LEDs only work one way - current must flow from anode (+) to cathode (-).
Different semiconductor materials produce different wavelengths of light.
LEDs need current-limiting resistors to prevent burnout from too much current.
Put your new knowledge into practice!