DIY LED REVOLUTION/EVOLUTION! INTRODUCING MEvo

jubiare

jubiare

Active Member
FROM KNNA on the reds

You dont need to use deep red at all for flowering. That is sure, checked and very well proven. Other thing is you can get a higher spectral efficacy (yield per emitted watt) using it. Its not a dramatic increase, thus I didnt used it until efficient deep reds got released very little ago.

But now you can get them and use them at similar and still higher efficiencies than standard red, it makes sense to use them , at least partially. Advantage is higher photosynthetic potential for same watts, due they emits mote photons than standard reds at same energy efficiency, and higher photosynthetic response (not much higher, on the other hand).

On veg, deep red works wonderful, the practical difference is more noticeable. In general, deep red advantage is larger as lower the irradiance level used.
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staf82

Member
Got another question for you, if i had 21x 3w leds wired in series could i get them to work on a 350mA constant current driver? and if so would they still use as much voltage or would they use more or less?
I would realy like to build a light that i can change from the equvalent of 1w to 3w easily.
 
Rasser

Rasser

Active Member
420greendream said:
hey so im sitting here smoking a blunt and thinking about my light. and i was thinking....why have 100 emitters? what if there was a super big led bulb...kinda like a hps light bulb, then it can be put on a reflector and kick ass. if thats possible and if you know enough about electronics to build the first one, thats a million dollar idea. bet. and when u make millions dont forget about your buddy 420greendream! :blsmoke: stay smooth yall
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Temperature is the reason why, thinks of LED's as computer chips.

A 100W LED module dispense the same heat as a Intel/AMD 4+ core CPU running 100%
So you need a big CPU cooler for each 100W module. Or use water cooling.

Wiki
Most of the electricity in an LED becomes heat rather than light (about 70% heat and 30% light). If this heat is not removed, the LEDs run at high temperatures, which not only lowers their efficiency, but also makes the LED less reliable. Thus, thermal management of high power LEDs is a crucial area of research and development. It is highly necessary to keep the junction temperature below 120°C to run the LED's for maximum lifetime.
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PSUAGRO.

PSUAGRO.

Well-Known Member
Hey Jubiare...........any updates on your girls????........great discussions in here/nice^^^those junction temperature graphs always get to me though:P
 
420greendream

420greendream

Well-Known Member
ive never seen his modules but i mean like a normal hps light bulb but have it be led and be the perfect spectrum of light.
 
jubiare

jubiare

Active Member
staf82 said:
Got another question for you, if i had 21x 3w leds wired in series could i get them to work on a 350mA constant current driver? and if so would they still use as much voltage or would they use more or less?
I would realy like to build a light that i can change from the equvalent of 1w to 3w easily.
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as patrik already pointed out to you, yes you can, they'll be efficient but you won't be driving them at full potential ... also you'll need more diodes to accomplish good results. Leds driven softer, more expensive solution, leds driven harder, less expensive solution. Maybe you want to look at drivers with an external potentiometer very handy and regulate the intensity. They are a little difficult to source. There is others with internal potentiometer and others with more expensive tools required to be mounted externally to regulate the leds. The voltage will vary, you'll have to look at datasheets, have a look at them and get familiar with them

PSUAGRO. said:
Hey Jubiare...........any updates on your girls????........great discussions in here/nice^^^those junction temperature graphs always get to me though:P
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hey fella yes there has been an update just today if you scroll up.. it went lost in discussions :oI even lit a few candles in there in honor of your method :cool:
 
Rasser

Rasser

Active Member
jubiare said:
yeah the soldering is between fun and pain... it takes it's time! if I was to get a soldering iron again I'd spend more maybe.. for a better one... 30w is what I used.. it's fine but takes more time to heat things up!
The tube is warm to the touch:o But I can stay with my hand on it with no discomfort.... I put the thermometer on top of it for a while, it reaches 94F ..... what do you say? I'd be gutted to have to employ fans oh no! LED's are spaced about at 2"
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I got this cheap soldering 'station':


besides having some stiff cables, it works great with the dimmer when soldering different sizes of materials.
Of course anything above that with build in temperature display and so on is great, but if you just need a cheap one then this type will be sufficient.

It's understandable that you don't want fan noise, I just wonder what a single silent fan blowing the hot air inside the tube out, would do for temps.

And remember when someone ask for data of your unit to include dB fan noise :-)
That was for sure a subject that kicked me ind the bud, or picked my brain more likely.
 
jubiare

jubiare

Active Member
a fan in the tube would work wonders yes. From one end pulling air in the tube I guess. The use of the tubes comes originally from nicolaj06, he used fans and his array should be on youtube somewhere.

Your soldering station looks just fine, better investment than a cheap low watt iron (I already broke one had to replace it hihihi)
 
PetFlora

PetFlora

Well-Known Member
patrikantonius said:
What ?

According to these charts:

most 660nm LEDs have better radiometric efficiency than their 630nm siblings

I did the math myself for the Cree XP-E 625nm and everything checks out.
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Those charts are Greek to me.

My C/P that you quote is missing the first part

(i.e. 630nm red is ~95% of the PSR of 660nm, AND they currently still have ~20-30% greater radiometric efficiency - as well as being cheaper than the deep reds - so there's more 'bang for the buck'):
 
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patrikantonius

Active Member
The charts represent the radiometric efficiency of different LEDs of different colors. The radiometric efficiency is in the last column of each table (Φe / P), and the greater the better.

You can see for instance that the Philips Luxeon 660nm is more efficient than its 627nm brother. That's why your statement surprised me.

PS: the chart contains LEDs of similar bins and most of them are among the best on the market. I think it is very relevant.

edit: where did you copy that from and how old is it ?
 
Gastanker

Gastanker

Well-Known Member
The chart does show that within the same family the 660s can offer a higher efficiency but on average the 630s are still more efficient - so it seems you really need to be picky about which brand diodes you are talking about when making the comparisons. 630s still might be the better "bang for the buck" - at least if you aren't being picky about the brand. In the chart the 630s average 33.2 while the 660s average 28.75.
 
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patrikantonius

Active Member
Gastanker said:
The chart does show that within the same family the 660s can offer a higher efficiency but on average the 630s are still more efficient - so it seems you really need to be picky about which brand diodes you are talking about when making the comparisons. 630s still might be the better "bang for the buck". In the chart the 630s average 33.2 while the 660s average 28.75.
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That's another interpretation haha.
Yeah basically it depends on the manufacturer. Philips and Osram (which have the best quality LEDs in the market) make better 660s than 630s but some other manufacturers (such as Ledengin) make better 630s than 660s.
 
Gastanker

Gastanker

Well-Known Member
Also depends on how you're running them right? As show in the charts the 3w LEDs are being run at >1w which could have a drastic bearing on efficiency. Don't most people run their reds at higher than 350mA? Or are those 1w aside from the LED Engines?
 
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patrikantonius

Active Member
Osrams can be run at 1000mA/2.7v, I believe they can be qualified as 3w. Philips and Crees max out at 700mA/2.4v -- I believe that's what some might call 2w LEDs.
The Philips (Luxeon) seem to be the best LEDs on the market for grow lights: they have the best efficiency and it decreases far less than any other LED when increasing the current. I'd love to build a panel with top bin Luxeons but damn these are expensive as shit.
 
jubiare

jubiare

Active Member
it depends which cree, xp-e red are rated at 700 but blue or/and whites at 1000. But XP-G whites are rated at 1500 so you want to drive them at 1050Ma or something ..... anyway, that's why with price/performance ease of use gd+ are usually your best bet

And anyway despite what they are rated at, you always have to get familiar with datasheets and make a wise decision, for instance some 1watters can be driven slightly harder than max allowed!
 
jubiare

jubiare

Active Member
IMG_20120703_162824.jpg

IMG_20120703_162909.jpg

Right, meVEG did a pretty good job but it was time to transplant I need to get the Autopot system going soon!

I have now split the space, we all want to see how MEvo does on it's own and also GLH '12 I need to know how it performs on its own. MEvo has had 6 red emitters taken away, cooler heatsink, it runs now at 75ish watts

Plants have been holding back since transplant? They could grow faster.. they are not looking bad though .....

I have used coco blocks for the first time, I haven't flushed them guys... just soaked for 12 hours? Is that bad?

Anyway plants were flushed prior transplant, day after were transplanted and fed half strength dose, which was a few days ago. They are not going to be watered again til they get really thirsty, I want to push the roots to go to the bottom towards the remaining water

You see that plant under the spectra is a little droopy, stem isn't stable either .... I might toss her, don't want any potential phytium s**t, am scared of that this round. The thing is when I get the Autopot system going I risk of contaminating healthy plants with sick plants ... so the first signs of some kind of weak plants phytium like, goodbye my baby.

MEvo at 12", Spectra at 24"

Let's see what happens
Thanks
 
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staf82

Member
Just thought i would ask for some more help, i have took apart my HGL pro and was gonna re use some leds but the solder is different to what i expected. It wont melt with a soldering iron so was wondering if you knew what they have used as i cant get them off the pcb, many thanx
 
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