High power LEDs have a much higher light output than indicaton LEDs, but still function the same way electrically.
For some high power LEDs, multiple LEDs are connected in series on the die, so they need a higher voltage to function properly. Check the datasheet to see which type you have at hand.
LED drivers usually take care of powering the LED properly (with constant current instead of constant voltage). Like other LEDs dimming can be done through a microcontroller and PWM (Pulse Width Nodulation).
Heat is the enemy of every semiconductor, especially for high power ones. High power LEDs, although very efficient, can generate tremendous amounts of heat. Therefore, high power LEDs function better and longer when heat is taken away from the package. An aluminium star construction on which the LED is glued (used for flash lights) can help to connect to a proper heat-sink. Other LEDs need to be screwed on a heat-sink. Use glue for small LEDs, and heat conductive heat-sink paste for larger LEDs to prevent small air bubbles between LED and heat-sink from causing premature failure. Once more check the datasheet on cooling requirements.
Light output is usually measured in Lumen, but Lux and mcd (candela) can also be encountered. These units have different measurement methods and are thus not easily comparable.
Warning: power LEDs are very bright. Do not look directly at it. Turn the power LED away from you and do not shine into the eyes of others.
Most important specifications
- Forward voltage depending on the led (V)
- Maximum forward current (A)
- Cooling requirements
- For white high power LEDs: Light temperature (K). 2700 K for very warm white light – 6500 K for cool white light