What kind of Led is this?

I found the led (pics can be found in attachments) in auto power failure light.
I was surprised to see how bright it was. I measured the voltage with a multi-meter. It was 3. something. I was surprised to see how a 3 volt light can perform so well. I also guess that the metal on its back is heatsink.

Now my questions are

  1. What knid of LED is this?
  2. How much does it cost?
  3. Is it available in different colors?
  4. How much current does it take to drive it?
  5. Can it be driven from an arduino directly?

And by the way can somebody tell me how to post pictures directly instead of posting them as attachments?

Thanks in advance. :slight_smile:

led0.jpg

Led 1.jpg

led 2.jpg

Looks a bit like a Lumiled.

Ufoguy:
I found the led (pics can be found in attachments) in auto power failure light.
I was surprised to see how bright it was. I measured the voltage with a multi-meter. It was 3. something. I was surprised to see how a 3 volt light can perform so well. I also guess that the metal on its back is heatsink.

Now my questions are

  1. What knid of LED is this?
    Generally I believe they are just called ‘high power’ LEDs
  2. How much does it cost?
    Depends on the power rating and perhaps color. Getting cheaper all the time, check Ebay
    http://www.ebay.com/sch/i.html?_trksid=p3984.m570.l1313&_nkw=high+power+led&_sacat=0&_from=R40
  3. Is it available in different colors?
    Yes
  4. How much current does it take to drive it?
    Depends on their wattage ratings, I believe the 1 watt ones require 300ma, 3 watt = 700ma, etc.
  5. Can it be driven from an arduino directly?
    No, their current requirements are much to high for direct connection to digital output pin, High power LEDs usually are powered from a constant current driver modules of which some have a digital input pin so that one can control the brightness via a digital PWM signal.
    Lefty

And by the way can somebody tell me how to post pictures directly instead of posting them as attachments?

Thanks in advance. :slight_smile: