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BRIGHT BRIGHT leds, where to get them? — Parallax Forums

BRIGHT BRIGHT leds, where to get them?

JedJed Posts: 107
edited 2009-03-17 20:58 in BASIC Stamp
I'm looking for a supply of of super super bright LEDS. I found THIS and THIS on ebay. The one is twice as expensive as the other, but it's also got a metal heat sink. Does that mean it's going to be brighter? How do I know the brightness of leds when I'm buying them?

Also, do I just need a transistor and resistors to connect a couple of these up to the stamp?

Comments

  • SRLMSRLM Posts: 5,045
    edited 2009-03-12 23:06
    Sparkfun has some very bright LEDs, as measured in mcd. They should be at this link, although it appears to be down right now. I got a few and tested them out, and found that one red LED, viewed head on, can be seen for 1000+ feet (I couldn't find any longer clear space). They are really quite bright.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-03-12 23:17
    For the last word on LEDs, visit the LED Museum. It's a very funky site, but it's jam-packed with the latest info on LEDs of all kinds from scads of different manufacturers.

    -Phil
  • JedJed Posts: 107
    edited 2009-03-12 23:25
    Wouldn't a 12 volt LED still be brighter than a 3 volt led though? Also, will I need to make a heat sink for the LEDs from Sparkfun if I buy those?
  • SRLMSRLM Posts: 5,045
    edited 2009-03-13 00:18
    The 12 volt LED setup probably just chains several LEDs in a row. You won't need a heatsink for any of the through hole LEDs. You might need a heatsink if you can pack a bunch of high power SMD LEDs together, but I've never tried that so I don't know.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-03-13 02:05
    There's no such thing as a 12V LED. An LED module that runs from 12V includes either a series string of LEDs or a single LED with either a resistor ballast (energy wasteful), a linear regulator (equally wasteful), or a switching regulator.

    -Phil
  • jmalaysiajmalaysia Posts: 97
    edited 2009-03-13 04:36
    The brighter the LED the more likely it will require a heatsink. I deal with the type in police lightbars which at this point are retina-burning bright. All of the superbright LEDs I see have a heatsink. One of the initial problems with them was they got so hot that the solder melted, so yeah, get something with a heatsink if you really need superbright.
  • ercoerco Posts: 20,257
    edited 2009-03-13 09:38
    There are Luxeon stars, which are 1-5 watt surface mount, aluminum-heat-sinked high-power LEDs. These are used in flashlights, bike lights, headband lights, etc. VERY bright and they run hot, which wastes power. These can take several hundred milliamps to power them.

    Seperate from that, there are 5mm ultra-bright (the brightest) and super-bright (less bright)·LEDs that run off of 20 mA and stay cool for higher efficiency. These use 1.7-2.4 volts depending on the color. Non-diffused clear epoxy cases with a flat front are extremely bright over a wide viewing angle.


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    ·"If you build it, they will come."
  • JedJed Posts: 107
    edited 2009-03-13 15:44
    I need as bright as absolutely possible. I asked the seller with the heat sink LEDs if they were super or ultra and he says they are ultra bright leds that are used for backlit signs like marquees and monuments out in front of businesses, so I think I may go with those. Seems he also dropped the price, so I may get a few and see how they go.
  • TWRackersTWRackers Posts: 33
    edited 2009-03-16 16:57
    I got mine from http://www.superbrightleds.com/leds.htm.· Check out the 1 watt LEDs specifically.
  • cgatescgates Posts: 4
    edited 2009-03-17 20:58
    lot's of different types of hi-power/bright LEDs:

    http://www.ledsupply.com/
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