DiY LED - Cree CXA3070

nogod_

nogod_

Well-Known Member


Doer said:
Hey, Godling. I looked at the spec and I have to say, I don't really get it. I liked it at first but the details seem strange.

It fully encases the COB with 2 sides, and an "inserted" thermal pad, "inside the bottom layer" ??? I could be turned around without the data sheet, but sounds like a high thermal impedance system.

Just a raw guess.
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nogod_

nogod_

Well-Known Member
Nahh I dunno if they are even available actually. Did a quick search after I posted and cant find em anywhere.

I really like how everything is shielded and you just run the wire back thru to the top of the heatsink á la stardust. I copied that for mine but wish I had these holders.

Doer said:
Ah, I get it now. Thanks. Did you see any prices on these holders?
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K

Kuifje76

Well-Known Member
CellarDweller said:
Very interested in how you are spacing them. Will post my designs soon
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Originally I was going to use less 3000K cobs and a few 5000K in the middle, but since I have 20...
I'm just afraid i'm loosing too much penetration if i go too low in mA, but for my surface 10cob, 2x5 is ideal for spacing, a bit less then a square foot (25cm2) for every 3000K cob
the 120cm UV-ledstrip from Phobya for me is a done deal :), but for extra blue or red i don't know, I could easily build a reflector for 3 ledstrips :)
 
Doer

Doer

Well-Known Member
Kuifje76 said:
Originally I was going to use less 3000K cobs and a few 5000K in the middle, but since I have 20...
I'm just afraid i'm loosing too much penetration if i go too low in mA, but for my surface 10cob, 2x5 is ideal for spacing, a bit less then a square foot (25cm2) for every 3000K cob
the 120cm UV-ledstrip from Phobya for me is a done deal :), but for extra blue or red i don't know, I could easily build a reflector for 3 ledstrips :)
Click to expand...
Nice. http://www.performance-pcs.com/phobya-led-flexlight-highdensity-120cm-144x-smd-leds-uv.html#!prettyPhoto[gallery]/1

$40
 
K

Kuifje76

Well-Known Member
I thought i'd put them in U-profiles to have more of a beam, but i guess not enough lm/par for the wattage ?
I say a review on youtube, and since you don't want to much UV either, I thought they would be enough for a closet
 
Doer

Doer

Well-Known Member
Kuifje76 said:
I thought i'd put them in U-profiles to have more of a beam, but i guess not enough lm/par for the wattage ?
I say a review on youtube, and since you don't want to much UV either, I thought they would be enough for a closet
Click to expand...
Well, I have used lizard lamps, and I think it does help. Hard to say. I know the theory. And I like to baseline with sunlight, fwiw.

http://www.ijdvl.com/article.asp?issn=0378-6323;year=2002;volume=68;issue=4;spage=198;epage=201;aulast=Balasaraswathy
In the present study at Coimbatore, India we measured the UVa and UVB irradiance for one year using PMA 2100 meter. UVB irradiance was mazimum between 12.00 noon- 1.00 p.m (19.50µw/cm2 to 40.2µw/cm2) and UVA between 12 noon-1.15 p.m. (4.70mw/cm2 tp 6.59mw/cm2). The ratio of UVA was 1:500 to 1:600 during early hours and late evening and 1:200 during mid-day.
----------------------------------
Notice how there is 500-600 times more UVA.

So, what I did with HPS was calculate the distance at which the photon Flux
was approx. Sunlight power. I got 25 inches distance more or less for 1000w.

What we need is efficient LED and driver combo that can give 20 - 40µw/cm2 at a reasonable distance, like 4 inches. If I had that I would just string them around like Christmas light.
 
C

CellarDweller

Well-Known Member
Doer said:
Well, I have used lizard lamps, and I think it does help. Hard to say. I know the theory. And I like to baseline with sunlight, fwiw.

http://www.ijdvl.com/article.asp?issn=0378-6323;year=2002;volume=68;issue=4;spage=198;epage=201;aulast=Balasaraswathy
In the present study at Coimbatore, India we measured the UVa and UVB irradiance for one year using PMA 2100 meter. UVB irradiance was mazimum between 12.00 noon- 1.00 p.m (19.50µw/cm2 to 40.2µw/cm2) and UVA between 12 noon-1.15 p.m. (4.70mw/cm2 tp 6.59mw/cm2). The ratio of UVA was 1:500 to 1:600 during early hours and late evening and 1:200 during mid-day.
----------------------------------
Notice how there is 500-600 times more UVA.

So, what I did with HPS was calculate the distance at which the photon Flux
was approx. Sunlight power. I got 25 inches distance more or less for 1000w.

What we need is efficient LED and driver combo that can give 20 - 40µw/cm2 at a reasonable distance, like 4 inches.
Click to expand...
Am thinking of using UVA / UVB LEDs at good power (photon density) for 2 hours a day either side of noon. If you calculate the angle of sun vs time of day vs time of day (something I have for various locations in my attempt to prove that it's almost impossible to hit your vitamin D requirements in northern Europe....which I proved) you'll find that in essence there's only a few viable hours of UVA / UVB per day most days of the year.

Interestingly I read this:

UVB, 285 nm-320 nm, causes unique reactions not duplicatied by other wavelengths. It also causes damage.
The plant responds by putting a protective coating on the underside of the leaves, this does not interupt the good spectrum coming from the sun, UVB in nature is non directional, half hits the bottom of the leaf. That is the reason for sidelights only with UVB, toplighting causes just the damage.

Source:

http://www.marijuana.com/community/threads/uva-b-an-uva-a-mega-buds.301517/
 
K

Kuifje76

Well-Known Member
it would be for peak noon only :), I grew mj 10 years ago and saw the effects even after the plant was harvested, i tried drying under them and it could be my idea but i thought it was trippier with uv then without.
 
C

CellarDweller

Well-Known Member
I am growing non-marijuana plants and something about UVA/UVB makes me think it's necessary - the chemistry in plants that we rely on is (according to numerous sources) reliant on a number of factors, and they aren't all positive, so UV stress is surely essential.

Who knows. The only way to know for sure is to test. Which I will :)
 
Doer

Doer

Well-Known Member
According to multiple sources (NASA, FDA, and others) here are the wavelengths of the UVA, UVB and UVC regions:

UVA 400 nm - 320 nm
UVB 320 nm - 290 nm
UVC 290 nm - 100 nm

So, unless I am missing something, no LEDengin fits the bill. This is the closest.
LZ4-00U600 Ultraviolet (365 nm peak) UVA range.
 
C

CellarDweller

Well-Known Member
Doer said:
According to multiple sources (NASA, FDA, and others) here are the wavelengths of the UVA, UVB and UVC regions:

UVA 400 nm - 320 nm
UVB 320 nm - 290 nm
UVC 290 nm - 100 nm

So, unless I am missing something, no LEDengin fits the bill. This is the closest.
LZ4-00U600 Ultraviolet (365 nm peak) UVA range.
Click to expand...
You're absolutely right....and I have to stand corrected.....UVB is not included.

However, I will say in my defence, that the margin for error on emitted nm can be quite high and therefore in trying to attain UVB with a 30nm potential for moving easily to UVC is "frightening". In the words of a rap song that was never written "UVC ain't nuttin ta f*ck wit"
 
Doer

Doer

Well-Known Member
CellarDweller said:
You're absolutely right....and I have to stand corrected.....UVB is not included.

However, I will say in my defence, that the margin for error on emitted nm can be quite high and therefore in trying to attain UVB with a 30nm potential for moving easily to UVC is "frightening". In the words of a rap song that was never written "UVC ain't nuttin ta f*ck wit"
Click to expand...
No attack no defense needed.

Don't fuck with with UVC!

That's the chorus. OK. Song is finished. Good job.

Oh I got another line.

I been stung by my cancer light, my cancer light, my cancer light. :)
 
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