Stealth LED Array light .

Positivity said:

Just got done doing some reading on sanding heatsinks straight from the cree website. It mirrors a lot of what you are doing.. I need to take my time on that area a bit more.

Could I tap your knowledge a bit sds..

Regarding pots...250k is recommended. But I'll be running two drivers so half that is 125k.

You think 150k would be alright? Theres a better selection in 150k with a 10% tolerance rating.

And one other..a little more on topic since it's a feature you've been using. I'd like to start integrating a ammeter to display the current I'm running. That'd be really useful running these cobs...any led really. I saw the analog like yours is a straightforward hookup but id like to try a digital.

The digital can run off my dc fan supply?

And...they have a dual voltage/current model. A little unnecessary but could be helpful. Seems to make more of a wiring mess.

Is the dual ammeter as much extra wiring as it seems?

Just running through options for my veg light...I'm in no rush to use it so I thought I'd try some new things..

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stardustsailor said:

Good info ,Salmo.
Thanx a lot !

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salmonetin said:

http://www.infineon.com/dgdl/IFX_Whitepaper_Intelligent Over Temperature Protection for LED Lighting Applications.pdf?folderId=db3a30431400ef68011407a99bd00180&fileId=db3a304344d727a80144df6b18780bea

http://www.cypress.com/?docID=22513

saludos

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Mohican said:

Mirror polish! Do you use a buffing wheel?

Any new news from the tomb dig?

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Mechmike said:

It has 6 chanels. One for each of the 5 strings of 3 Veros +2 stars and one for the 660s. My last run was 15.3 ounces. Not too bad for 6 square feet. It has a lot to do with the 96 Cree CXA1304 cobs surrounding the plants in the other 4 levels of bars. They're the 9v version slightly underdriven at 300ma.

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engines. Unlike discrete LEDs with plastic lenses,these light engines are small printed-circuit wafers that pack
large numbers of small LEDs of selectable emission colors into close proximity. For example, the ORBITEC
light engine can array 132 LEDs of five colors in a 6.25 cm2 square (Massa et al., 2005a). This allows for
unprecedented color blending and very bright light levels.LED emissions are current-controlled, and the light output
is directly proportional to input current within their operating range, so unlike other types of dimming
systems for lighting, dimming of LEDs directly reduces power usage. LEDs have solid-state construction, are
extremely durable, and resistant to shock. Transparent coatings on the chips protect them against high humidity
and allow for cleaning without reducing light levels. LED chips, like discrete LEDs, have low mass and volume.
LEDs generally emit light in a narrow region of the color spectrum. The number of available colors is extrem
ely large, with one of the most efficient being red LEDs emitting at 640 nm, where light has a relative quantum
efficiency for photosynthesis of ~96% (Sager and McFarlane, 1997). Experimentation has demonstrated
that different species can be grown successfully under LEDs, including spinach (Goins and Yorio, 2000), lettuce
(Goins et al., 2001; Kim et al., 2004), radish (Goins et al.,2001), wheat (Goins et al., 1997), and micropropagated
potato plantlets (Miyashuta et al., 1995).

Generally, about 15% blue light is required for normal growth, and yields have been achieved that are comparable to growth under white light (Yorio et al., 199.

Research hasdemonstrated that green light also can have beneficial effects for growth and plant assessment, especially within dense foliar canopies (Kim et al., 2004; 2005)

.........

Hey-hey-hey !!!!
It seems that they 've always 'knew' about " white light " ,eh ?

When considering a light source for ALS, several important characteristics must be kept in mind: A
variety of light sources have been evaluated from this perspective. LEDs, especially the relatively new chip-on-board LED light engines, appear to be optimal lighting systems for ALS crop growth for a variety of reasons. As a rapidly developing technology, electrical efficiency of these light sources continues to increase. In addition, the ability to precisely select a spectrum that is efficient for photosynthesis, growth, and flowering, the durable solid-state nature of LEDs, the relatively cool emitter surface,their long lifetime, tunability of the spectrum and irradiation levels, and ability to easily remove heat all combine to make this lighting type the best contender for ALS crop production. When the benefits of LEDs are coupled with techniques that apply light only where there is photosynthetic capability, the increased lighting efficiency will result in a significant reduction in the power required to maintain desired levels of biomass production, reducing the cost of growing plants in an ALSS, and bringing crop growth on Luna and Mars that much closer to reality.

Cheers !

stardustsailor said:

The 'known' parts ....

- 200 mm x 160 mm x 40 mm AA 1060 16-fined hetsink .(raw )
-2x Cree CXA3070 led arrays ( 3000K -80 CRI -AB )
-2x Ideal holders (had some spare ... )
-Arctic Silver 5 .

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JBox said:

Hey SDS I've been really enjoying watching your build and am now starting my own. One problem I'm having is that I can't find any CXA3070 3000K AB bins for anything less that a quantity of 20. So we're talking like a grand when I only need two or three.

Where did you get these CXA's from?

Thanks,
J

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