Recognize LED - The first step to DIY LED light

What is LED?

It is a semiconductor light source.

Here is the definition of LED (Light Emitting Diode) in Wikipedia:


Shapes of LED:

LEDs are maked to many shapes and sizes.

The most common one is 5mm diameter round head (cylindrical) LED.

This is a 5mm LED. With power connected. It emits red light.

The 2 legs are the anode and cathode of the LED. The longer leg is Anode and the shorter leg is cathode.



Functions of LED

LED is making to many colors. Such as Red, Orange, Green, Blue, Purple and white lights.

There are also infrared LED and UV LED in the market.

Some LED got more than one diode inside. That different color may able to be emitted from one LED.

For visible light LED, we make it to signal boards, lights or decorations.


Property of LED:

LED is very easy to use as a low voltage can light up it. It is not easy damage under shocks.

Typical life of LED is 50,000 - 100,000 hours which is several times longer than a bulb.

LED is in very good power efficiency.

But we should be extra care about the voltage on the LED. Over voltage will damage the LED.




How to light up a LED?

It is so easy to do. Slightly electrical power is enough to light up a LED.

Use a lithium cell battery, such as CR2016 or CR2035 and connect the legs to the button cell.

The LED will be light up immediately.

The picture shows a 5mm multi-color LED powered by a CR2032 button cell battery.

You can use a tape to fix the LED and battery together. Then it is suits for decoration or a small toy.

Such as stick on a kite. It will be the spark one in the night.

The CR2032 battery can light up the LED for more than 24 hours.


Copyright 2010, Images and Document by Tommy