C.O.B.S.S.L. News and Articles

Positivity · Oct 23, 2014

FranJan said:
Philips Luxeon COBs
http://www.philipslumileds.com/

http://www.philipslumileds.com/products/luxeon-cob
View attachment 3279412

LUXEON COB Application Brief:
http://www.philipslumileds.com/uploads/426/AB115-pdf
LUXEON COB Product Datasheet:
http://www.philipslumileds.com/uploads/419/DS115-pdf

Luxeon with Crisp White

View attachment 3279413
LUXEON CoB with CrispWhite Technology Product Brief:
http://www.philipslumileds.com/uploads/483/PB138-pdf
LUXEON CoB with CrispWhite Technology Datasheet:
http://www.philipslumileds.com/uploads/482/DS138-pdf

Features & Benefits

90CRI with CrispWhite enhancement for perfect combination of warm colors and white that stands out!

Hot targeted within a 3-Step MacAdam Ellipse below the BBL that is ideal for CDM-CMH replacement

Creating a second blue peak (~410-415nm) in the spectrum that activates fluorescent whitening agents paints/fabrics

Lumen packages from 1,000 to >5,000 lumens and efficacies of >90 lm/W

Real world application testing conditions at Tj=85°C

Robust MCPCB solution - easy to handle in manufacturing and operations

Mousebites for M2/M3 easy to screw down arrays

There we go..that crisp white is looking good. I was wondering when they were going to extend the blue peak. Very nice..

AquariusPanta · Oct 23, 2014

Positivity said:
There we go..that crisp white is looking good. I was wondering when they were going to extend the blue peak. Very nice..

Everyone in the market is trying to sell sunny-side eggs and pancakes :eyesmoke:

Mohican · Oct 23, 2014

Or growing weed?

AquariusPanta · Oct 23, 2014

Mohican said:
Or growing weed?

lmao

FranJan · Oct 23, 2014

COB Pricing + Availability

CREE, Bridgelux, and Luminus Devices COB Quick Links:
Courtesy of
http://www.eciaauthorized.com

---------------------------------------

Link to this post
http://rollitup.org/t/c-o-b-s-s-l-news-and-articles.848298/page-3#post-10994088

AquariusPanta · Oct 23, 2014

FranJan said:
COB Pricing + Availability

CREE, Bridgelux, and Luminus Devices COB Quick Links:
Courtesy of
http://www.eciaauthorized.com

CREE 3070:
All Bins, Kelvins + CRIs
http://www.eciaauthorized.com/search?pn=CXA3070-0000

3000K AB Bin
http://www.eciaauthorized.com/search?pn=CXA3070-0000-000N00AB30F
3000K Z4 Bin
http://www.eciaauthorized.com/search?pn=CXA3070-0000-000N00Z430F

CREE 3590:
All Bins, Voltages, Kelvins + CRIs
http://www.eciaauthorized.com/search?pn=CXA3590-00
3000K 36V BD Bin
http://www.eciaauthorized.com/search?pn=CXA3590-0000-000N00BD30F
3000K 36V BB Bin
http://www.eciaauthorized.com/search?pn=CXA3590-0000-000N00BB30F
3000K 77V BD Bin
http://www.eciaauthorized.com/search?pn=CXA3590-0000-000R00BD30F
3000K 77V BB Bin
http://www.eciaauthorized.com/search?pn=CXA3590-0000-000R00BB30F

Bridgelux Vero 29:
2700K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-27E10
2700K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-27G10
3000K CRI 80
http://www.eciaauthorized.com/search?pn=BXRC-30E10
3000K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-30G10
3500K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-35E10
4000K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-40E10
4000K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-40G10
5000K 70 CRI
http://www.eciaauthorized.com/search?pn=BXRC-50C10
5000K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-50E10
5000K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-50G10
Bridgelux Vero 18:
2700K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-27E40
2700K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-27G40
3000K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-30E40
3000K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-30G40
3500K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-35E40
4000K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-40E40
4000K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-40G40
5000K 70 CRI
http://www.eciaauthorized.com/search?pn=BXRC-50C40
5000K 80 CRI
http://www.eciaauthorized.com/search?pn=BXRC-50E40
5000K 90 CRI
http://www.eciaauthorized.com/search?pn=BXRC-50G40

Luminus Devices - XNOVA CXM-27s + 22s
CXM-27
All Kelvins , MacAdam Ellipses + CRIs
http://www.eciaauthorized.com/search?pn=CXM-27

CXM-27 3000K 80 CRI including 2 + 3 Step McAdams
http://www.eciaauthorized.com/search?pn=CXM-27-30-80
CXM-27 5000K 80 CRI including 2 + 3 Step McAdams
http://www.eciaauthorized.com/search?pn=CXM-27-50-80

CXM-22
All Kelvins, MacAdam Ellipses + CRIs
http://www.eciaauthorized.com/search?pn=CXM-22

CXM-22 3000K 80 CRI including 2 + 3 Step McAdams
http://www.eciaauthorized.com/search?pn=CXM-22-30-80
CXM-22 5000K 80 CRI including 2 + 3 Step McAdams
http://www.eciaauthorized.com/search?pn=CXM-22-50-80

---------------------------------------

Link to this post
http://rollitup.org/t/c-o-b-s-s-l-news-and-articles.848298/page-3#post-10994088

A very cool search engine Frannie.

If only I had more space... and more money... and time... much more free time

:blsmoke:

Al Yamoni · Oct 23, 2014

Does anybody know of a source for the CXA3070 AB 3000k where I can get singles or even maybe ten? I don't think I ever be able to justify 40..

stardustsailor · Oct 24, 2014

Broadband vs Narrow .Episode I

An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra

Abstract
Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner.

Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra.

Whereas specific responses of plants to a spectrum differing from natural daylight may sometimes be predictable, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses.

So far studies on plant responses to spectra either use no daylight control or, if a natural daylight control is used, it will fluctuate in intensity and spectrum. An artificial solar (AS) spectrum which closely resembles a sunlight spectrum has been engineered, and growth, morphogenesis, and photosynthetic characteristics of cucumber plants grown for 13 d under this spectrum have been compared with their performance under fluorescent tubes (FTs) and a high pressure sodium lamp (HPS).
The total dry weight of the AS-grown plants was 2.3 and 1.6 times greater than that of the FT and HPS plants, respectively, and the height of the AS plants was 4–5 times greater. This striking difference appeared to be related to a more efficient light interception by the AS plants,

characterized by longer petioles, a greater leaf unfolding rate, and a lower investment in leaf mass relative to leaf area.

Photosynthesis per leaf area was not greater for the AS plants.

The extreme differences in plant response to the AS spectrum compared with the widely used protected cultivation light sources tested highlights the importance of a more natural spectrum, such as the AS spectrum, if the aim is to produce plants representative of field conditions.

Introduction

The irradiance spectrum to which plants are exposed during growth has specific effects on different types of plant responses such as photosynthesis, photomorphogenesis, phototropism, and photonasty.

In plant research and greenhouse horticulture, lamps (growth lamps) with different spectral outputs are widely used to provide the growth irradiance. The most commonly used lamp types are fluorescent tubes (FTs) and gas-discharge lamps, which emit a spectrum with pronounced emission lines which are characteristic for the different lamp types. More recently light-emitting diodes (LEDs), which are characterized by relatively narrow-band spectra, have become increasingly used in growth cabinets, on an experimental basis in greenhouse horticulture, and in research on growing plants in space (Hogewoning et al., 2007; Massa et al., 2008; Trouwborst et al., 2010). A common feature of these light sources is that their spectrum does not resemble that of natural daylight, which has a continuous (i.e. without strong emission lines) spectrum in the PAR region (400–700 nm), even though some lamp emissions appear ‘white’. (<= RGB arrays)

Plants have evolved under broadband spectra and are exposed to spectral differences under natural conditions dependent on weather conditions, time of day, season, and their growth environment.

For example, when the sky is cloudy, daylight contains relatively more blue and less far-red (FR) between 700 nm and 750 nm than in full sunlight (Holmes and Smith, 1977). A low sun angle is associated with a low red to FR (R:FR) ratio (Franklin and Whitelam, 2007). Other factors that affect the natural spectrum are altitude, depth for aquatic plants, and, most obviously, shading by neighbouring vegetation. Inherently, leaves exposed to a shade or a sun spectrum are also exposed to a relatively low and a high irradiance, respectively, so irradiance and spectrum are often linked.

Specific parts of the spectrum are involved in sun and shade light responses of plants. Blue light and high R:FR ratios are known to induce the development of sun-type chloroplasts (Lichtenthaler, 1980; Kasperbauer and Hamilton, 1984). A low R:FR ratio is a textbook example of a spectrum inducing an overall shade-type morphology in a wide range of species, typically characterized by etiolation so that plants can reach above neighbouring plants (e.g. Grime, 1981). Other spectral responses do not overtly parallel a shade or sun spectrum response. Such responses include blue light-induced stomatal opening (e.g. Zeiger, 1990; Willmer and Fricker, 1996), which can be reversed by adding sufficient green light to the spectrum (Frechilla et al., 2000; Talbott et al., 2002), or reduced growth and photosynthesis when plants are grown under red light alone (e.g. Brown et al., 1995; Goins et al., 1997; Yorio et al., 2001; Matsuda et al., 2004). Many spectral responses of plants are regulated via photoreceptors, such as phytochromes, cryptochromes, and phototropins, which alter the expression of a large number of genes (Whitelam and Halliday, 2007). These numerous and complicated spectrum-regulated plant responses have been, and remain, the subject of extensive study.

Research on spectral responses of plants normally involves adding irradiance from growth lamps to daylight, modifying daylight using spectral filters, using solely growth lamps, or a combination of these methods.
Whereas the specific responses of plants to a spectrum deviating from natural light may sometimes be predictable based on published research, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses.

For instance, spectra enhancing the photosynthetic capacity of leaves per unit leaf area do not necessarily enhance a whole plant morphology which is favourable for light interception and therefore also do not necessarily enhance plant production.(<=a bell rings for the deep reds ....)

The lack of a practical source for an irradiance whose spectrum resembles that of any kind of natural daylight means that it is difficult, or impossible, to have a controlled environment in which natural daylight-adapted plants can be grown. Plant studies using a daylight spectrum are always conducted under conditions of natural daylight which fluctuates in intensity and spectrum. This makes a clear distinction between plant responses to the intensity or the spectrum of the irradiance difficult. In the past the main criterion for an optimal growth chamber spectral irradiance was a natural plant appearance with a high production yield (e.g. Deutch and Rasmussen, 1973), rather than producing a spectrum that is inherently like that of sunlight. So though mixtures of fluorescent and incandescent lamps have been used to allow more normal plant growth and development, this spectrum is very dissimilar to that of sunlight. A spectrum which closely resembles a sunlight spectrum has now been engineered. Growth, morphogenesis, and photosynthetic characteristics of young cucumber plants grown for 2 weeks under this artificial sunlight spectrum have been compared with their performance under lamp types widely used in growth chambers or glasshouses. A growth irradiance was used in which assimilation was light-limited (or nearly so) to minimize possible effects of different assimilation rates per leaf area, caused by differences in the irradiance response of assimilation, on plant growth and development. The plants grown under the artificial sunlight developed in a strikingly different way from the plants grown under the other lamps tested. An artificial solar (AS) spectrum offers the opportunity to grow plants under controlled conditions which are far more representative of field conditions than plants grown under the current growth chamber irradiance sources.

To read the rest of the article:
http://jxb.oxfordjournals.org/content/61/5/1267.full

stardustsailor · Oct 24, 2014

Broadband vs Narrow .Episode II

Whereas in climate chambers the growth-light spectrum is often constant, in greenhouse cultivation natural daylight is sometimes supplemented with light provided by growth-lamps, so that the crop is subjected to strongchanges in its spectral environment. Especially at latitudes with short natural photoperiods in winter, assimilation lamps are used
in greenhouses to lengthen the photoperiod and increase the total irradiance at times when natural irradiance is relatively
low (Heuvelinket al., 2006). High pressure sodium (HPS) lamps are the supplemental light sources that are commonly used in greenhouses, though recently light-emitting diodes(LEDs) have been proposed as potential replacements for HPS lamps (Hogewoninget al.,2007).
The large diversity of narrow-band spectra emitted by LEDs creates a challenge for their efficient use in horticulture, because plant responses to their restricted spectra are poorly understood.

A large bibliography of studies on plant responses to the intensity of irradiance has become available over the years. Plant responses to the light spectrum are relatively less well understood, despite detailed studies on specific features such as red:FR ratios (R:FR;e.g. Smith, 2000) or short term responses of relative photosynthetic efficiency to different narrow-band spectra (e.g. Balegh and Biddulph, 1970; McCree, 1972a; Inada, 1976; Evans,1987).

In general, a wide range of plant properties respond to the spectral environment, such as photosynthesis, photomorphogenesis, phototropism and photonasty.

The limitless range of spectral compositions, and changes in spectrum, make a comprehensive, overall understanding of plant responses to their spectral environment a virtually impossible task.

A subdivision of the broad range of plant responses to the spectral environment into different levels of time and function helps to structure the various ways that irradiance-spectra can influence plant growth. A schematic overview is given in Fig. 1. The subjectscovered in this thesis focus on the responses of leaf photosynthesis and development to
the spectral environment. In particular this study is focuses on:

1. The adaptation of leaf photosynthesis and related leaf morphological and chemical characteristics to the spectral environment.
2. The acclimation of leaf photosynthetic quantum yield and photosystem stoichiometry of leaves which have developed underdifferent spectra and the consequences of acclimation for the wavelength dependence of photosynthetic quantum
yield.
3. The consequences for plant production of spectrally induced plantmorphological changes in relation to leaf
photosynthesis.

The rest here :
http://edepot.wur.nl/154537

AquariusPanta · Oct 24, 2014

stardustsailor said:
Broadband vs Narrow .Episode I

More recently light-emitting diodes (LEDs), which are characterized by relatively narrow-band spectra, have become increasingly used in growth cabinets, on an experimental basis in greenhouse horticulture, and in research on growing plants in space (Hogewoning et al., 2007; Massa et al., 2008; Trouwborst et al., 2010). A common feature of these light sources is that their spectrum does not resemble that of natural daylight, which has a continuous (i.e. without strong emission lines) spectrum in the PAR region (400–700 nm), even though some lamp emissions appear ‘white’. (<= RGB arrays)

The last sentence mentioned LED light fixtures not providing enough continuous red, green, and blue light.

Is that including the white chip COBs that our club preaches so highly of, such as the pancake and sunny-side-up egg models? Surely not but I would like to clarify, as some of these reports were made over four years ago.

I'm under the impression that my Vero 18's (4k) do include a large spectrum that resembles daylight.

:leaf:

guod · Oct 24, 2014

!!!!!! Warning !!!!!!
you see here Spectra that build of narrow band monochromatic Led.

full spectrum Sunlike
with 26 Leds

with 18 Leds

-------------------------------------
full spectrum for Plants
with 8 Leds

http://www.phytotronic.de/index.php/LEDtechnology.html

stardustsailor · Oct 24, 2014

guod said:
!!!!!! Warning !!!!!!
you see here Spectra that build of narrow band monochromatic Led.

full spectrum Sunlike
with 26 Leds
View attachment 3279849
with 18 Leds
View attachment 3279851

-------------------------------------
full spectrum for Plants
with 8 Leds
View attachment 3279850

http://www.phytotronic.de/index.php/LEDtechnology.html

http://atrium.lib.uoguelph.ca/xmlui/bitstream/handle/10214/7718/Hawley_David_2013_MSc.pdf?sequence=1

But from the other hand ...

http://www.surechem.com.my/products/901003-101039-PDF.pdf

FranJan · Oct 24, 2014

Fuck COBs and their phony sunlight

. They are soooo 10 minutes ago.

Osram Opto Demonstrates "3D nano LEDs" for White Light and Sees Series Maturity in Coming Year

"The prototype chip has a five to ten times larger surface on the same substrate than current LED chips, and thereby generates significantly more light in relation to the base area. In addition the luminous efficacy will be increased by approximately 10% in the future."

http://www.led-professional.com/technology/light-generation/osram-opto-demonstrates-3d-nano-leds-for-white-light-and-sees-series-maturity-in-coming-years

Nanoco, Osram Sign Development Agreement for LED “Natural” Light

"Quantum dots open up new potential for LED lighting, which currently lacks the same warmth and colour performance of an incandescent bulb and have the capacity to appeal to a new set of buyers who want the efficiency and economy of the LED, as well as the “effect” of natural light. To date, the use of quantum dots in lighting was hindered by the fact that the technology contained cadmium (Cd), a highly-regulated and toxic heavy metal. Nanoco’s technology, made without cadmium or any heavy metal, offers a sustainable solution, according to the company."

http://www.novuslight.com/nanoco-osram-sign-development-agreement-for-led-natural-light_N3189.html

http://www.novuslight.com/nanoco-osram-sign-development-agreement-for-led-natural-light_N3189.html

You know what? Fuck LEDs too . They're so .214456786th of a second ago!

Beyond LEDs: Brighter, New Energy-saving Flat Panel Lights Based on Carbon Nanotubes
"Electronics based on carbon, especially carbon nanotubes (CNTs), are emerging as successors to silicon for making semiconductor materials. And they may enable a new generation of brighter, low-power, low-cost lighting devices that could challenge the dominance of light-emitting diodes (LEDs) in the future and help meet society's ever-escalating demand for greener bulbs."

http://www.ledinside.com/news/2014/10/beyond_leds_brighter_new_energy_saving_flat_panel_lights_based_on_carbon_nanotubes

So here's to the future mates bongsmilie

. Hopefully the deny-a-sauruses and the ignore-a-sauruses go extinct too. :mrgreen:

stardustsailor · Oct 24, 2014

Bridgelux Vero Décor 97 CRI

http://www.bridgelux.com/wp-content/uploads/2013/10/DS34-Bridgelux-Vero-Decor-Datasheet-2014.02.03.pdf

http://www.bridgelux.com/wp-content/uploads/2013/10/DS28-Bridgelux-Decor-High-CRI-Array-Data-Sheet-2013.10.22.pdf

PetFlora · Oct 24, 2014

Love all the info, but how's the new panel performing?

stardustsailor · Oct 24, 2014

PetFlora said:
Love all the info, but how's the new panel performing?

I've been building constantly 'new panels' lately...
Let's keep this kind of chit-chat ,to another thread of mine ,more relative with my DIY builds .
Thank you .

stardustsailor · Oct 24, 2014

Bridgelux Vero DECOR analysis.

BXRC-30H4000-F-xx

-CCT: 3000°K
-CRI: 97
-max If : 2100mA
-Driving modes : HE =1050 mA , NM= 1575 mA ,HO= 2100 mA
-max Tc : 105°C
-full Vf range (min 85°C,500mA /max 25°C ,2000mA ) : 23-35 VDC

Spectrum:

Spectral Analysis :
( From digitising job ..)

- Estimated LER **400 nm -780 nm ** = 272,3 lm/Wφ
-Excitation peak (die) λ0= 452 nm / .587 Rel. to 1
-Emission peak (phosphor) λ1= 633 nm ( 1 )
- 642 nm ChB peak .Rel. to 1 = .969
- 662 nm ChA peak .Rel. to 1 = .808
-Stokes shift = 181 nm

*
For comparison purposes :
Average Stokes shift of 3000°K/80 CRI COBs , is as low as 145-155 nm .
CXA3070 3000°K/80CRI has a Stokes shift of 148 nm .
(λ0=454 nm / .485:1 , λ1=602 nm )

An 'on-the-field' rule of thumb to 'evalute' the Stokes losses is this
(although not very accurate in mean numbers):

{ 1- ( Excitation Peak / Emission Peak )= Stokes losses. }

So for the BXRC-30H4000-F-xx would be :
1 - (452 / 633) = 0.2859 = 28.6% of excitation radiant power is lost by Stokes Shift .
A pretty rough estimation ,handy mainly for quick comparisons between COBs...
For CXA 3000°K /80CRI the Stokes losses is 24.6% ,roughly calculated by the same rule of thumb ...
The Decor has ~16% more Stokes losses than the CXA of 80 CRI.

Band power distribution :
400-499 nm : 9.98 %
500-599 nm : 32.87 %
600-699 nm : 48.61 %
700-780 nm : 8.54%

Photobiology parameters
-R:FR (660:730) = 4.453
-PPE /PPS = 0.631
-Pfr : Pr = 1.708
-Pr : Pfr = 0.585
-YPF / PPF = 82.51 %
-Quanta per Radiant Watt = 4.97 umol

Math model Estimation Analysis #1 : ( for single C.O.B. unit ,)
Tc = 25°C ,If = 1050 mA ( HE 50% ) ,Vf = 29.5 VDC ,L = 2550 lm ,LumEff = 82 lm/W
PWR Dis = 30.975 W
Φο (Radiant Output Power ) = 9.365 W
Heat Pwr = 21.61 W
Radiant Efficiency = 30.23 % ( .3023 )
Quantum Efficiency = 1.5 umol/J
Quantum Flux (400-780 nm ) = 46.55 umol/sec

Math model Estimation Analysis #2 : ( for single C.O.B. unit ,)
Tc = 85°C ,If = 1050 mA ( HE 50% ) ,Vf = 27.9 VDC ,L = 2200 lm ,LumEff = 75 lm/W
PWR Dis = 29.295 W
Φο (Radiant Output Power ) = 8.079 W
Heat Pwr = 21.22 W
Radiant Efficiency = 27.58 % ( .2758 )
Quantum Efficiency = 1.37 umol/J
Quantum Flux (400-780 nm ) = 40.16 umol/sec

Personal View & D.I.Y. Note :

A ) ~28% efficiency at 85°C (worst case ) & operated at HE mode 50% ( 1050 mA ) ...
B ) ~ 10% Fr & ~ 49% of power at 600-699 nm ...
C ) < 10% at 400-499 nm ...

~60% of output power is over the 600 nm ...
It's like a "hypothetical" combo of 1: 5 :3 : 1 ( FR : DR -R :GR: BL ) monochromatic leds..
(Of hypothetical equal efficiency ...BTW, how much would be the actual total / average efficiency of such combo ,really ? - ... A rough estimate ? )
....
Personally,I'd use it /them ...From mid to late flowering ..
When all the 'stretching' ability of the plant(s) is a past thing ...
I'm bettin' that those high CRI 3000°K are really " bud-swellers" ...
Althought pretty 'unefficient' comparing to their 80 CRI counterparts ...

2700° K whites are differing from the 3000K whites only in the amount of power of BL
wls.No matter the CRI. Personally I'd avoid ..2700 K whites ,due to their bigger phosphor load.
Thus less efficient than the 3000K .
The difference of 80 CRI 3000K and 90-97 CRI 3000K whites ,is the actual phosphors & blends used.High CRI have longer emission (oxy)nitride phosphors,that though more efficient in conversion than yellow/amber YAG ones ,the bigger Stokes losses,unfortunately can not be avoided .
Still the spectra provided by the high CRI 3000K COBs ,I'm sure will prove to be ..
well..at least "bud-swelling" ....I'm bettin' on it ...Only restriction is the ~10% FR ...

Thus ,that kind of white light should be utilised after the mid of flowering ,towards the end of sensimilla's ..reproductive (!) .... cycle .

Would I use them ?
Yes ...
In one another 'dream-light' that will contain 7 cobs per heatsink (honeycomb arrangement ) ,
in three independent driving channels :

1x 5000° K ,70 CRI ,as seed/clone/early veg enhancing-supplementing light .
&
4x 3000 °K ( or 3500 °K for Vero line ) ,80 CRI ,as main light core .
&
2x 3000°K ,90 CRI (or 97 for Vero Decor /Xnova Studio line ) ,
as mid-late flowering enhancing -supplementing light .

AquariusPanta · Oct 24, 2014

stardustsailor said:
Bridgelux Vero DECOR analysis.

BXRC-30H4000-F-xx

-CCT: 3000°K
-CRI: 97
-max If : 2100mA
-max Tc : 105°C
-full Vf range (min 85°C,500mA /max 25°C ,2000mA ) : 23-35 VDC

Spectrum:
View attachment 3280058

Spectral Analysis :
( From digitising job ..)
View attachment 3280059

- Estimated LER of 3000°K Vero Decor **400 nm -780 nm ** = 272,3 lm/Wφ
-Excitation peak (die) = 452 nm / .587 Rel. to 1
-Emission Peak (phosphor) = 633 nm ( 1 )
- 642 nm ChB Rel. to 1 = .969
- 662 nm ChA Rel. to 1 = .808
-Stokes Shift = 181 nm

Band power distribution :
400-499 nm : 9.98 %
500-599 nm : 32.87 %
600-699 nm : 48.61 %
700-780 nm : 8.54%

Photobiology parameters
-R:FR (660:730) = 4.453
-PPE /PPS = 0.631
-Pfr : Pr = 1.708
-Pr : Pfr = 0.585
-YPF / PPF = 82.51 %
-Quanta per Radiant Watt = 4.97 umol

Math model Estimation Analysis #1 : ( for single C.O.B. unit ,)
Tc = 25°C ,If = 1050 mA,Vf = 29.5 VDC ,L = 2550 lm ,LumEff = 82 lm/W
PWR Dis = 30.975 W
Φο (Radiant Output Power ) = 9.365 W
Heat Pwr = 21.61 W
Radiant Efficiency = 30.23 % ( .3023 )
Quantum Efficiency = 1.5 umol/J
Quantum Flux (400-780 nm ) = 46.55 umol/sec

Math model Estimation Analysis #2 : ( for single C.O.B. unit ,)
Tc = 85°C ,If = 1050 mA,Vf = 27.9 VDC ,L = 2200 lm ,LumEff = 75 lm/W
PWR Dis = 29.295 W
Φο (Radiant Output Power ) = 8.079 W
Heat Pwr = 21.22 W
Radiant Efficiency = 27.58 % ( .2758 )
Quantum Efficiency = 1.37 umol/J
Quantum Flux (400-780 nm ) = 40.16 umol/sec

Summary-Personal View :
Well ...
A ) ~28% efficiency at 85°C & If = ~1A
B ) ~ 10% Fr & ~ 49% of power at 600-699 nm ...
C ) < 10% at 400-499 nm ...

~60% of output power is over the 600 nm ...
It's like a "hypothetical" combo of 1: 5 :3 : 1 ( FR : DR -R :GR: BL ) monochromatic leds..
(of hypothetical equal efficiency ...BTW, how much would be the actual total / average efficiency of such combo ,really ? - ... A rough estimate ? )
....
Personally,I'd use it /them ...From mid to late flowering ..
When all the 'strecthing' ability of the plant(s) is a past thing ...
I'm bettin' that those high CRI 3000°K are really " bud-swellers" ...
Althought pretty 'unefficient' comparing to their 80 CRI counterparts ...

( Note : 2700 K whites are differing from the 3000K whites only in the amount of power of BL
wls.No matter the CRI. Personally I'd avoid ..2700 K whites ,due to their bigger phosphor load.
Thus less efficient of 3000K .The difference of 80 CRI 3000K and 90-97 CRI 3000K whites ,is the actual phosphors & blends used.High CRI have longer emission (oxy)nitride phosphors,that though more efficient in conversion than yellow/amber YAG ones ,the bigger Stokes losses,unfortunately can not be avoided .

Still the spectra provided by the high CRI 3000K COBs ,I'm sure will prove to be ..
well..at least "bud-swelling" ....I'm bettin' on it ...Only restriction is the ~10% FR ...

Thus ,that kind of white light should be utilised after the mid of flowering ,towards the end of sensimilla's ..reproductive (!) .... cycle . )

Would I use them ?
Yes ...
In one another 'dream-light' that will contain 7 cobs per heatsink (honeycomb arrangement ) ,
in three independent driving channels :

1x 5000° K ,70 CRI ,as seed/clone/early veg enhancing-supplementing light .
&
4x 3000 °K ( or 3500 °K for Vero line ) ,80 CRI ,as main light core .
&
2x 3000°K ,90 CRI (or 97 for Vero Decor /Xnova Studio line ) ,
as mid-late flowering enhancing -supplementing light .

How long has LED lighting and growing the forbidden fruit been your passion?

:leaf:

stardustsailor · Oct 24, 2014

AquariusPanta said:
How long has LED lighting and growing the forbidden fruit been your passion?

Should I account for the total time invested from my previous 'rides' also,
or just from the current one ?

:bigjoint:

L3G4CY · Oct 24, 2014

stardustsailor said:
Broadband vs Narrow .Episode I

An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra

Abstract
Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner.

Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra.

Whereas specific responses of plants to a spectrum differing from natural daylight may sometimes be predictable, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses.

So far studies on plant responses to spectra either use no daylight control or, if a natural daylight control is used, it will fluctuate in intensity and spectrum. An artificial solar (AS) spectrum which closely resembles a sunlight spectrum has been engineered, and growth, morphogenesis, and photosynthetic characteristics of cucumber plants grown for 13 d under this spectrum have been compared with their performance under fluorescent tubes (FTs) and a high pressure sodium lamp (HPS).
The total dry weight of the AS-grown plants was 2.3 and 1.6 times greater than that of the FT and HPS plants, respectively, and the height of the AS plants was 4–5 times greater. This striking difference appeared to be related to a more efficient light interception by the AS plants,

characterized by longer petioles, a greater leaf unfolding rate, and a lower investment in leaf mass relative to leaf area.

Photosynthesis per leaf area was not greater for the AS plants.

The extreme differences in plant response to the AS spectrum compared with the widely used protected cultivation light sources tested highlights the importance of a more natural spectrum, such as the AS spectrum, if the aim is to produce plants representative of field conditions.

Introduction

The irradiance spectrum to which plants are exposed during growth has specific effects on different types of plant responses such as photosynthesis, photomorphogenesis, phototropism, and photonasty.

In plant research and greenhouse horticulture, lamps (growth lamps) with different spectral outputs are widely used to provide the growth irradiance. The most commonly used lamp types are fluorescent tubes (FTs) and gas-discharge lamps, which emit a spectrum with pronounced emission lines which are characteristic for the different lamp types. More recently light-emitting diodes (LEDs), which are characterized by relatively narrow-band spectra, have become increasingly used in growth cabinets, on an experimental basis in greenhouse horticulture, and in research on growing plants in space (Hogewoning et al., 2007; Massa et al., 2008; Trouwborst et al., 2010). A common feature of these light sources is that their spectrum does not resemble that of natural daylight, which has a continuous (i.e. without strong emission lines) spectrum in the PAR region (400–700 nm), even though some lamp emissions appear ‘white’. (<= RGB arrays)

Plants have evolved under broadband spectra and are exposed to spectral differences under natural conditions dependent on weather conditions, time of day, season, and their growth environment.

For example, when the sky is cloudy, daylight contains relatively more blue and less far-red (FR) between 700 nm and 750 nm than in full sunlight (Holmes and Smith, 1977). A low sun angle is associated with a low red to FR (R:FR) ratio (Franklin and Whitelam, 2007). Other factors that affect the natural spectrum are altitude, depth for aquatic plants, and, most obviously, shading by neighbouring vegetation. Inherently, leaves exposed to a shade or a sun spectrum are also exposed to a relatively low and a high irradiance, respectively, so irradiance and spectrum are often linked.

Specific parts of the spectrum are involved in sun and shade light responses of plants. Blue light and high R:FR ratios are known to induce the development of sun-type chloroplasts (Lichtenthaler, 1980; Kasperbauer and Hamilton, 1984). A low R:FR ratio is a textbook example of a spectrum inducing an overall shade-type morphology in a wide range of species, typically characterized by etiolation so that plants can reach above neighbouring plants (e.g. Grime, 1981). Other spectral responses do not overtly parallel a shade or sun spectrum response. Such responses include blue light-induced stomatal opening (e.g. Zeiger, 1990; Willmer and Fricker, 1996), which can be reversed by adding sufficient green light to the spectrum (Frechilla et al., 2000; Talbott et al., 2002), or reduced growth and photosynthesis when plants are grown under red light alone (e.g. Brown et al., 1995; Goins et al., 1997; Yorio et al., 2001; Matsuda et al., 2004). Many spectral responses of plants are regulated via photoreceptors, such as phytochromes, cryptochromes, and phototropins, which alter the expression of a large number of genes (Whitelam and Halliday, 2007). These numerous and complicated spectrum-regulated plant responses have been, and remain, the subject of extensive study.

Research on spectral responses of plants normally involves adding irradiance from growth lamps to daylight, modifying daylight using spectral filters, using solely growth lamps, or a combination of these methods.
Whereas the specific responses of plants to a spectrum deviating from natural light may sometimes be predictable based on published research, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses.

For instance, spectra enhancing the photosynthetic capacity of leaves per unit leaf area do not necessarily enhance a whole plant morphology which is favourable for light interception and therefore also do not necessarily enhance plant production.(<=a bell rings for the deep reds ....)

The lack of a practical source for an irradiance whose spectrum resembles that of any kind of natural daylight means that it is difficult, or impossible, to have a controlled environment in which natural daylight-adapted plants can be grown. Plant studies using a daylight spectrum are always conducted under conditions of natural daylight which fluctuates in intensity and spectrum. This makes a clear distinction between plant responses to the intensity or the spectrum of the irradiance difficult. In the past the main criterion for an optimal growth chamber spectral irradiance was a natural plant appearance with a high production yield (e.g. Deutch and Rasmussen, 1973), rather than producing a spectrum that is inherently like that of sunlight. So though mixtures of fluorescent and incandescent lamps have been used to allow more normal plant growth and development, this spectrum is very dissimilar to that of sunlight. A spectrum which closely resembles a sunlight spectrum has now been engineered. Growth, morphogenesis, and photosynthetic characteristics of young cucumber plants grown for 2 weeks under this artificial sunlight spectrum have been compared with their performance under lamp types widely used in growth chambers or glasshouses. A growth irradiance was used in which assimilation was light-limited (or nearly so) to minimize possible effects of different assimilation rates per leaf area, caused by differences in the irradiance response of assimilation, on plant growth and development. The plants grown under the artificial sunlight developed in a strikingly different way from the plants grown under the other lamps tested. An artificial solar (AS) spectrum offers the opportunity to grow plants under controlled conditions which are far more representative of field conditions than plants grown under the current growth chamber irradiance sources.

To read the rest of the article:
http://jxb.oxfordjournals.org/content/61/5/1267.full

Natural sunlight spectra is mostly `flat`. If you notice the peak absorbtion of chloropyll A & B, you notice 4 peaks which is: 425, 465, 630 and 660nm. Than you can add a neutral white 3500-5000K to add all spectrums. This combo would be in a 1:1:1:1:1

This would result to a sunlight photosynthesis boosted spectra that potentially can give more performance than just flat sunlight spectra.

What you guys think?

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