The high-pressure sodium (HPS) lamp has been the preferred light source for year-round crop production in greenhouses. The main reasons have been the high radiant emission, low price, long life time, high PAR emission and high electrical efficiency. These factors have allowed the use of high-pressure sodium lamps as supplemental lighting sources supporting vegetative growth in a cost-effective way during wintertime in northern latitudes. However, the spectral quality in HPSs lamps is not optimal for promoting photosynthesis and photomorphogenesis, resulting in excessive leaf and stem elongation. This is due to the unbalanced spectral emission in relation to the absorption peaks of important [0015] photosynthetic pigments such as chlorophyll a, chlorophyll b and betacarotene. The low R/FR ratio and low blue light emission in comparison with other sources induces excessive stem elongation to most of the crops grown under HPS lighting. Electrical efficiencies of high-pressure sodium lamps are typically within 30 % and 40 %, which make them the most energy- efficient light sources used nowadays in plant growth. Approximately 40 % of the input energy is converted into photons inside the PAR region and almost 25 % to 30 % into far-red and infra red. The operation times of high pressure sodium lamps are in the range from about 10,000 to 24,000 hours
[0094] A LED lighting fixture was constructed for comparison testing purposes based on the single LED device having identical output spectrum of the Figure 3. The lighting fixture consisted of 60 individual LED units having a power consumption of 69 W which includes the power consumption of the AC/DC constant current driver.
[0095] The comparison devices were commercial HPS (High Pressure Sodium) lamp greenhouse lighting fixture with total power consumption of 420W and commercial LED greenhouse LED fixture. The commercial LED fixture was based on individual blue and red LED devices having total power consumption of 24W.
[0096] The LED lighting fixture according to the present invention was tested against the above- mentioned commercial LED devices using following PPF measurement procedure and arrangement.
[0097] PAR irradiance (irradiance value between 400 nm and 700 nm) and PPF- values were calculated by measuring the light fixture spectra from 300 nm to 800 nm and absolute irradiance value at band from 385 nm to 715 nm. The spectrum of each lamp were measured with ILT700A spectroradio meter at one distance. The absolute irradiance- values were measured with precision pyranometer at certain distances and were later used to calculate the absolute spectra to these distances. These absolute spectra were used to calculate PAR- and PPF calculations. PAR-irradiance (W/m[SUP]2[/SUP]) was calculated by integrating the absolute spectrum from 400 nm to 700 nm. PPF-values were calculated by first translating the irradiance value of each "channel" of the spectrum from W/m[SUP]2[/SUP] to microeinsteins and then integrating this spectrum over the desired wavelength band.
[0098] The comparison result of these two commercial greenhouse lamp fixtures and the LED fixture according to the innovation are presented in the table below. The results are also normalized against the commercial HPS lighting fixture. Type HPS Ref. Grow LED LED of Invention
Still I think ,that customised WW & CW (<=YAG / silicate combo phosphors,there ) ,^^^^^
What he said!!
Though, I didn't realize the huge leap in efficiency, if this is true........
That would mean 300-400 watts of led (or less) replaces 1k of HPS.
Close.....
If I had the money: (simplified!)
No need for that big amount of money...
If you want to keep with DIY in that way ,I suggest you start searching for a small but quality led manufacturer..
With some e-mails,you won't believe how many things you can "customise" ,even for small orders (i.e. 300-500 leds... )
Turn the led/diode into a transistor.
Control the phosphors with the base.
Treat the spectrum as a wave and shift the thing red or blue predicated on base current.
This could also be configured in a triode or pentode configuration.?????
Meaning ? ----Simplified..My electronics are bit rusty there...
Control the spectrum of the luminaire with a graphic equalizer with all of the leds putting out the same bandwidth and frequency response.
Oh to dream.
The rhetorical question.
How many runs would it take to fined the sweet spot at a given stage of development?
Oh ..plenty I guess ,but not so many as one may think...
Astir is finding it's " way " there ,step by step....
Yeah I still don't buy it/it's for a patent...........A good quality(philips) 400w hps bulb will put out around 600umol/s ( can't link on my phone) and I'm not even going to bring up the Gavita 1000w hps system that get's over 1.5ppf/w .......then their is the king philips 315w agro elite(cmh) which almost hits 2 ppf/w!!! hid is not dead yet SDS....
Cycloptics is about to go commercial with their luminaire. It ain't cheep. About $600.00 a pop.Yeah I still don't buy it/it's for a patent...........A good quality(philips) 400w hps bulb will put out around 600umol/s ( can't link on my phone) and I'm not even going to bring up the Gavita 1000w hps system that get's over 1.5ppf/w .......then their is the king philips 315w agro elite(cmh) which almost hits 2 ppf/w!!! hid is not dead yet SDS....
So in my situation the initial purchase price is a wash, led vs Elite Agro.8 All-Bright in 36 sq ft = 1,167 micromoles X .97 (95% Mylar vs. 98% WhiteOptics) = 1,130 micromoles X 25% the area (9 sq ft vs. 36 sq ft) = 2 All-Bright delivering average intensity of 1,130 micromoles at 32 below apertures of All-Bright luminaires. With the units 50% dimmable you can deliver between approximately 565 and 1,130 micromoles.
The price for the 2 All-Bright luminaires including the Elite Agro 315W CMH lamp and without the Philips ballast will be $445.00 each. We accept Visa and can prepay and add the shipping via UPS ground. Let me know how you would like to proceed.
Multiple base legs to the transistor, each leg modulates the emitter collector junction in their own way.This could also be configured in a triode or pentode configuration.?????
Meaning ? ----Simplified..My electronics are bit rusty there...
I have no relationships with any factory's, nor do I have the chemistry lab to do the basic research.If I had the money: (simplified!)
No need for that big amount of money...
That's the problem, we have to make another luminaire every time we make a change, or pull one down out of production.How many runs would it take to fined the sweet spot at a given stage of development?
Oh ..plenty I guess ,but not so many as one may think...
Astir is finding it's " way " there ,step by step....
*That's why the plating of silver with rhodium....Although the silvering on a second surface mirror such as a household mirror is often actual silver the "silvering" on precision optical instruments such as telescopes is usually aluminum. Even though silver has the best initial front-surface reflectivity in the visible spectrum it is unsuitable for optical mirrors because it quickly oxidizes* and absorbs atmospheric sulfur to create a dark, low-reflectivity tarnish.
Although aluminum also oxidizes quickly, the thin aluminum oxide (sapphire) layer is transparent, and so the high-reflectivity underlying aluminum stays visible.
The "silvering" on infrared instruments is usually gold. It has the best reflectivity in the infrared spectrum, and has high resistance to oxidation and corrosion.
It may also be used in coating sterling silver to protect against tarnish, which is silver sulfide (Ag[SUB]2[/SUB]S) produced from the atmospheric hydrogen sulfide (H[SUB]2[/SUB]S). Solid (pure) rhodium jewelry is very rare, because the metal has both high melting point and poor malleability (making such jewelry very hard to fabricate) rather than due to its high price.[SUP][34][/SUP] Additionally, its high cost assures that most of its jewelry usage is in the form of tiny amounts of powder (commonly called rhodium sponge) dissolved into electroplating solution
check out :Other uses
Rhodium foil and wire
Rhodium is used as an alloying agent for hardening and improving the corrosion resistance[SUP][15][/SUP] of platinum and palladium. These alloys are used in furnace windings, bushings for glass fiber production, thermocouple elements, electrodes for aircraft spark plugs, and laboratory crucibles.[SUP][36][/SUP] Other uses include:
- An electrical contact material due to its low electrical resistance, low and stable contact resistance, and high corrosion resistance.[SUP][37][/SUP]
- Plated rhodium, made by electroplating or evaporation, is extremely hard and is used for optical instruments.[SUP][3[/SUP]
http://invetec21.com/elements/16.htmlRhodium metal is also used in the manufacture of super-hard mirrors to be subjected to high temperatures, as well as glass for use in high-powered laser systems.
Rhodium alloys are used in industry to make contact pairs, due to the high resistance of rhodium to electro-erosion.
http://www.theodoregray.com/periodictabledisplay/Elements/045/index.s7.htmlRhodium is the most reflective element in the periodic table and finds application in specialist mirrors for light houses, high performance car head lamps and searchlights. It is also used for front-coated dental mirrors where its resistance to scratching is useful.
So does this mean it should be used in early veg, but not flowering?warm white/640nm...(3-1)???????????? ha ....................you should give 660nm another shot, can't ignore it's effects on root development
And what percentage...It's not a matter of "if should be used " and "at what stage " ....
Of course it has to "be there ", at "all times " ..
The "problem " is "how much of it" and "combined with what else "....
Yeap!^^^ Well said!
As it relates to my response to 'whomever'. If we don't correct bad behavior, then by our silence, they assume we condone it.
At that very moment, we become culpable, otherwise known as Enablers. Look around, bad behavior has multiplied like rabbits
If WE don't hold this behavior accountable, who will?
Why does 660 have to be there at all times? Physically, yes, but not necessarily switched on. I have long been saying 660 @ ~ 7-10%, but on a separate circuit, just in case a particular strain/s doesn't like it