Introduction: Blue LED Light Box
Build your own blue LED light box to combat SAD and winter blues. Sleep better and wake up with more energy while exploring the world of high-power LEDs. If 18 watts of LED power isn't enough to wake you, just add more LEDs!
Also, check out Blue LED dawn simulator for Soleil Sun Alarm.
Step 1: Why Blue Light?
According to light box manufacturers 446 to 477 nm wavelength light is supposed to be the most effective for treating seasonal affective disorder (second to natural sunshine, of course). Instead of buying a commercial product that lacks external control and might be based on psuedo-science, I decided to take advantage of the rapidly falling price of high-power LEDs to build an 18-watt blue light.
Step 2: Materials
Here's what I used and where I got it.
Luxeon III Stars, (Lambertian) 3 blue (470 nm), 3 royal blue (455 nm) - Luxeon.com
BuckPuck 700 mA driver (03021-D-E-700) - TheLEDLight.com
30 volt DC power supply - RadioShack
1/8 Mono phone jack and plugs - Radioshack
lying around the shop but available at RadioShack or Jameco:
1/8 thick aluminum sheet approximately 8 x 10
#4-40 nylon screws and nuts
Step 3: Rough Cut and Drill Holes in Aluminum Base
The LEDs generate a lot of heat, so I mounted them in an aluminum base that could also act as a heatsink.
Cut the aluminum to size and mark where you want to mount the LEDs. I printed a template on paper and used it to mark where to drill mounting holes.
Step 4: Round Edges and Sand
Round the edges of the base and then sand it. I sanded with 100, 200, and 320 grit paper.
Step 5: Bend the Aluminum Base
Clamp pieces of wood to the front face of the base to keep it flat. Bend it into an upside-down "7" shape.
Step 6: Cut Mica
The back side of the LEDs is not electrically neutral, so they need to be isolated.
Cut thin pieces of mica, which is thermally but not electrically conductive, into the shape of the LEDs. I used a laser cutter, but you can also use the mica's existing shape and carefully drill holes to fit the LED's screws by starting with very small drills and working your way up.
Step 7: Mount LEDs
Put heat grease on both sides of the mica and sandwich it between the LEDs and the aluminum. Attach the LEDs with the nylon screws.
Step 8: Solder the LEDs Together
Solder the LEDs together in series and connect them to the LED power supply. The Buckpuck power supply will drive 700 mA up to its maximum voltage. Connect the DC power supply to the Buckpuck. You can solder all these connections, or if you want to do fancy external control, putting everything on a breadboard is easier.
Step 9: External Control
If you want to control the light from an external source, like a dawn simulator, bend up the backside corner and drill a hole to mount the 1/8 connector, or whatever connector is appropriate. If you are not going to do external control, you should at least put an on/off switch on the light.
Step 10: Mount Power Supply
Hot glue the DC power supply and bread board to the base.
Step 11: Felt Feet
If you're going to put the light on a nicely finished wood surface, put some felt feet on the bottom.
Step 12: Enjoy the Blue Glow
Bask in the blue glow of the LEDs. Some people use them in the morning to wake up, while others use them in the evening to help go to sleep. Run a few experiments and see what works best for you.