Speaking of white LEDs....

Here's a project that I finished recently. I got tired of turning on the light every time I wanted to pull out a record to listen to. I built this system of LED clusters to suspend over my records. Each cluster has three white LEDs with a 60 degree spread. They are powered by an LM317T. I scaled the adjustable voltage to give a current range in the LEDs of about 100uA to 18mA. There is a separate on/off switch for the lights so that I don't have to turn the whole PSU on or off. I even put a 470uF cap across the adjust pin so that the LEDs fade in and out slowly. I chose to use electrical boxes and conduit not only because they are cheap, but I happen to enjoy the industrial look.

pic1
pic2
pic3
pic4
pic5
pic6

I'm going to put another set above the next shelf where my 7"s and cassettes reside. I also have single LED suspended over the record player so that I can see the grooves.

I just noticed that in pic5 you can just barely see two MX5050s being used as the base for my coffee table :grin:

Nice work!

If you get a bit weary of the cold character of white LEDs, change one of the three in each set to an amber version. It creates quite a nice neutral feel to the light.

I was just working on an LED lamp, but a bit brighter:
http://www.avensonaudio.com/pics/8rebelproto.jpg

It uses 8 white LEDs running at 750 mA. It gets pretty hot, but it seems like it is working pretty well. Now for a reflector and maybe a diffuser.

These LED's are 4100K "neutral white"

Very cool work !!!

Ave DIY !!!

I've been meaning to build a UV cluster for night fishing.
Big UV led's are somewhat pricey, and I'm thinking I'd need about 5 or so.

:?: how much power consumption do you save with leds compared to halogen or ordinary bulbs?
Chances of having failure with leds are like tens of thousands times less then with standard lightbulbs?

and big up for Valvehead!
Always nice to see stuff I have been thinking about myself, actually built by someone!

[quote author="tony dB"]:?: how much power consumption do you save with leds compared to halogen or ordinary bulbs?
Chances of having failure with leds are like tens of thousands times less then with standard lightbulbs?[/quote]

The power LED cluster I have burns about 21Watts and is about as bright as a 50w incandescent bulb. I think the LED's I used are about 35 lumens per watt. A bulb is more like 15 lumens per watt. Not huge gains really, but interesting to play with. The light is much nicer than florescent.

cheers Brad!

The company i'm working for is now doing LED backlight replacements for CCFL LCDs...

Heating is the biggest issue, especially when the LEDs are in a display which was designed for CCFLs with large amounts of plastic surrounding the backlight channel.

Those Luxeon Rebels are nice arent they. Low junction to case thermal resistance and that nice isolated thermal pad on a ceramic package. Good thing you have that huge chunk of metal to attach them to. Some customers of ours who have attempted to make their own backlights have come to us and said "why are my LEDs turning brown?" :roll:

I like the Nichias too...

-Mike

http://www.otherpower.com/otherpower_lighting.html

I had run into that page when I was doing some research. The application I'm using the LED's in is generally a spot usage, so that helps me out. LEDs aren't really a good general purpose light yet, but I think they have some really good features.

I liked the rebels, but the PCB layout was a bit intense on the vias for the thermal pad. Not a DIY PCB. There are 192 vias in that PCB, but works since the heat transfers really well into the heat sink. I did wet-sand the aluminum slug for better flatness.