Instructables

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.
 
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calskin3 years ago
Do you remember an approximate cost of this project?
Ragasteady5 years ago
This design involves a risk for the eyes. According to Lumileds documentation :

"Blue and RoyalBlue power light sources represented here are IEC825 class 2 for eye safety."

http://en.wikipedia.org/wiki/Laser_safety#Class_2


This means that LED can cause damage is the user stares at them. HB LEDs should always have a diffusor in front of them.

Yes, all commercial LED light boxes have diffusers on them.
I am looking into the blue light hazard and while it is not completely settled at what point it starts to be dangerous, it is clear that small point sources will be much worse than diffuse ones. Given how powerful the Luxeons are, I would STRONGLY urge you to use a diffuser. Even a thick piece of vellum an inch (3cm) away would help a lot.

If the mechanism for BLH is as expected, even 480nm light is likely to be hazardous, and even when diffused. 505nm light ("Cyan" for Luxeons) would be < 10% as dangerous as blue while being 60% as effective for reducing melatonin levels (the presumed mechanism for reducing SAD and restoring circadian rhythm).

So I am looking at building a box with 505nm to replace my Philips unit.

Finally, make sure the light box is in your upper peripheral vision - it appears the receptors for melatonin/circadian are there, and the area of most concern for BLH is the macula (center point of vision).
robin676 years ago
just curious, why the controller and not just the power supply directly.
ewilhelm (author)  robin676 years ago
thanx, now it makes sense! great idea.any more cool instructs?
Farles7 years ago
Why use those Luxeon Leds, as you could simply use raw LEDs... anyways, looks great, love the aluminum shaping... gives me ideas :P
ewilhelm (author)  Farles7 years ago
I used the Luxeon's because they are much brighter.