But for this photo, I placed the glowing LED in some oil so that we can see through the plastic easily. The entire LED is usually encased in a plastic lens, making it very difficult to see. A yellow LED chip is glowing inside the little reflector cup. You can see two of those tiny little gold wires in the microphotograph above. At some point, the temperature of the LED is so high that the little chip inside the LED breaks, or the tiny little wires that connect to the top of the LED chip simply melt. If the number of electrons per second goes up, so does the temperature.

So eventually the LED reaches a stable temperature, where the amount of heat generated equals the amount of heat lost.Įach second, some number of electrons move through the LED.

The temperature rises, but as the temperature becomes higher than that of the surroundings, more of the heat is lost to the environment. As electrons move through a conductor such as a wire or an LED, they bump into the atoms in the conductor, causing the conductor to heat up. The second rule of light emitting diodes is that they can only handle a certain amount of electricity.Įlectricity is just moving electrons. At best, the LED would make a little 'pop' sound, and become a dark emitting diode, which we will call a DED. What would happen if we connected the LED to the battery in a car, or to a nine-volt battery? That would not be a good idea. The tiny little button battery in the photo above is just strong enough to light the LED. The first rule is the 'diode' part of the name at work: a diode only allows electricity to go through it in one direction. If it doesn't light up, turn it around and it will. If you connect one wire to the positive side of a battery, and the other side to the negative side of the battery, you have a 50% chance it will light up. Like all simple things, LEDs can seem a lot less simple if you don't know their simple rules.Īn LED has two wires coming out of it. You put electricity through it, and it lights up. We'll start with the light emitting diode (we'll call it an LED for short). There may be a lot of little things to play with, but each one is simple. Most of what an artist needs to know about electronics is very simple.

220 ohm resistor color code