Conversion calculators

Lumen / Lux Calculator
http://www.ledrise.com/shop_content.php?coID=19

Candela to Lumen
http://led.linear1.org/lumen.wiz

Requirements Analysis? (Updateable)

Blue light in 446-477 nm wavelength
PWM for intensity
3000 lux onto 50 cm^2 at approx. 75 cm away

Prelim research: reverse engineering

Product spec pdf

Findings:
Power
12W power = 3*3W LEDs required after efficiency (Power LEDs spread the light evenly)
Array
10*6=60 LEDs, assume 5mm
That's 3.92W assuming 20mA at 3.3V. (Then we'll need to spread the light)

Other:
Lithium Ion cells....
Case.

The goLITE BLU also features a wider field of light than other light boxes, which means that you can work, watch TV, read, or eat meals while using the light box, rather than having to sit close and directly in front of it.

So we'll have to spread the light out.

Power LEDs do seem more cost effective and simpler to deal with.

Power LEDs
http://cutter.com.au/products.php?cat=Cree+XPE
http://cutter.com.au/products.php?cat=Cree+XRE
http://www.dealextreme.com/details.dx/sku.11015
http://www.dealextreme.com/details.dx/sku.13289

5mm LEDs
http://www.dealextreme.com/details.dx/sku.9077

http://www.ledsales.com.au/cart.php?target=category&category_id=43

Maybe someone can do up an analysis on cost/power/performance etc

Prelim questions - ctd

Loose specs:

Sky blue light

3000 lux

Given by The Doctor :)

Tighter specs:

446-477 nm wavelength

3000 Lux ? (LED specs should give us a good idea of how many LEDs we need for the right lux)

Lighting duration ? (need to read more papers)

Dimming/lighting up ? (simulating dusk / dawn)

Directional lighting ? (do we need to worry about that?)

Anything else?

Refer to papers at: http://www.mcsaustralia.com.au/component/content/65.html?task=view

Need to find some more papers to find out the other stuff.

Prelim questions

What wavelength is sky blue? Tolerance/optics...
How much illumination are we aiming for? something that we can measure without buying a luxmeter??

Project Start

Pre-reading:
http://www.mcsaustralia.com.au/products/light-therapy.html

Video at the bottom:
http://www.amazon.com/Philips-goLITE-BLU-Therapy-Device/dp/B001I45XL8

Lux vs Lumen
http://en.wikipedia.org/wiki/Lux
http://www.candlepowerforums.com/vb/showthread.php?t=178086 <- Calculations

Sample DIY
http://www.instructables.com/id/Blue-LED-light-box/

Go-lite manual
http://www.cpapaustralia.com.au/media_files/golite-blu-positioning-gu.pdf

Blue light therapy study:
http://jdc.jefferson.edu/cgi/viewcontent.cgi?article=1002&context=jmbcimfp

LEDs and lighting:

http://green-energy-conservation.blogspot.com/2009/05/led-lighting-basics-and-definitions.html

Retina illumination study:
http://www.ncbi.nlm.nih.gov/pubmed/12568246?dopt=AbstractPlus