100 x 3w prolight leds for growlight help need for power and pulsing

[LED Growlights]

hi everyone im new to this

i would like to make a led array out of 100 3w prolight leds = 300watts heat will be a problem, so fans and lots of heatsink
i will use about 15 blue and 85 red to start with
i was thinking of using a psu from a computer rated at 400w for 12v
then i used the calculator on here to make an array is this the best way?
i would also like to pulse the leds and have a knob to turn to change how fast they flash if poss
any ideas for the simplest led driver + pulse curcuit
thanks

[Rob]

Welcome to the boards.

A 400W PSU is not rated for 400W on the 12V rail. Worse, it won't probably regulate correctly without a load on the 5V rail. What that means is you can't count on getting 12 volts out. That measnt he assumptions that go into the array calculator may not be valid. So in summary: not a great plan.

Think of the LEDs as current-driven devices. You want to provide the correct drive current, ideally with a current-regulated supply.

I'm going to take a wild guess from your user name that these lights will be shining on plants. I don't think you really do want to pulse them in that case. You really should be trying to maximize the amount of photons you deliver to the plants, and pulsing isn't how to do that.

What is going to power your array, mains current?

[LED Growlights]

hi
thanks for the quick reply
yep there gonna be powderd by 240v for uk
i read some where that plants react better to pulsing something to do with shadow flicker but dont hold me to that
what would be the cheapest, best way to power the leds
could i make it myself?
i would like the leds 20x5 rows
 
thanks

[LED Growlights]

dont worry about the pulsing
i need to go from
240v mains uk
to 12v or 24v not sure whats best is this correct?
then i need to power 100 3w leds in 20 x 5 row
Lens Color : Water Clear
Emitted Color : red
Intensity Typ. : 80~100Lm
Viewing Angle : 160°
Forward Voltage : 2.6v-2.8v
Forward Current : 650mA
thanks

[BVnursery]

2 spectrum led grow lights are a waste of plant growing time.  A quick look at any of the 1000's of sites coming up on any search engine looking for 'photosnythesis' will show that quite factually from a number of PHD level researchers.

85% red and 15% of blue, regardless of individual sprectrums are really a good ratio either.

You have a progressive idea, just one that needs a lot of research.

Any problem running the entire 100 in series off of rectified mains there ??
Bob

[LED Growlights]

im new to this so i dont know how to power them for 240v uk mains to 100w leds cheapest way
i was told i need between 1-35% blue?
these lights will be used for flowering like a hps it has more red in
metal halide has more blue in it for veging
here is one u can buy it has red and blue leds uses cree 1w  40 red and 16 blue which is about 35%
http://www.homegrownlights.com/100W.html

i can always add different colours later on when testing
heres some pics of what i would like to make



mark

[motobroker]

BV,
I've seen so many different opinions on the forums regarding  what spectral mix is going to work for Ag lights.
I am currently building some arrays using K2s and SSC P3s and P4s.
My guess is that it is going to take at least a year or  two to really figure out what Freqs are going to work.
What is your opinion on the 660nms and overall spectrum optimization

[BVnursery]

Im rather opinionated.   Plants require more than 2 sprectrums for P R O P E R growing.

Procylon is a 2 spectrum light.   2 spectrum lights are junk.  Will they grow plants? yes.
Will they grow plants properly ?  NO !  Plants will grow under an incandescent.

Regulated lighting for plant is much more than just firing up a light.  HPS/MH type lights waste 80%+ of the power drawn due to wrong spectrums.

Google ... photosynthesis

motobroker...  660nm are mandatory.  620nm is a waste of power.  IMO

 I use 5 spectrums in my seedling unit.

[LED Growlights]

i found the biggest prob was the cost of 660nms, can get 3w reds for $2.00 but there 630nm+or-10nm
630nm are cheap but just fall outside the peaks for photosynthesis
chlorophyll a has approximate absorbance max of 430 nm and 662 nm, while chlorophyll b has approximate max of 453 nm and 642
so in an ideal world
maybe 440nm and 650nm with a little orange maybe 612nm
also i have never seen high powered led growlights just little ones the largest being 100w which is not enough to grow under
600w hps is say maybe 75% heat 10% unusable light and the rest 15%  usable light
if a 600w is 90,000ln this would be about 13,000lm of usable light i think
so 100 3w(led) x 90lm is 9,000 were getting close is this right
ps is motobroker a shop or led make
mark

[motobroker]

BV,
 I presume you read Kinnza's post in the other grow light string where he was negative against the need for 660 nms.

Any comments on his thoughts?  You both seem like sharp guys who have done your homework. It just goes to show you how divided opinions are on this subject.  I don't think anyone has quite got it dialed in yet.

My approach is initially go with  a broad spectrum, including some of the high dollar 660s.  I will then gradually start to see what I can eliminate (or add).   I think it is going to be a long and expensive road for the guys trying to get this to work.
 I believe it is a going to be a lot tougher then most people realize. Some of the newer HID goodies have a half-way decent spectral distribution. Everyone seems to think that is where LEDS have a huge advantage.

I wouldn't mind communicating privately via email, IM or  skype with some other people who are seriously interested in trying to surpass HID performance.  I feel that there are a few people out there who are moving past the scope of the forums. 

[motobroker]

LED GL and BV,

Here is the problem the way I see it:
 HPS is putting out about 140 to 160  lumens/watt *. I readjust that number down to 110 lumens per watt to allow for losses in reflector.
  The best LEDs that are available to the little guy are probably averaging under somewhere under 70 lumens/watt. The best 630nms available at a decent price get about 40 lm/watt when driven at around 350ma.

In my opinion they underperform HPS on a watt to watt basis. So when I see claims that 100 watt led array like Procyn  replaces 400 watt HPS, I am more then skeptical.

[motobroker]

LED-GL, looking at your figures: You can't take the heat loss into account, since the 90k lumens are what is produced in conjuction with heat loss.  Going with your 10%/15% ratio on good light/bad light, that would give us 35k usuable lumens from an HPS.  So you got 35k Lms usuable light instead of 13k Lms for the hps.

Also take a look at the spectral power distribution of a Hortilux.  That bulb and the ceramic MHs seem to be doing a decent job. They have really improved with getting the spectrum moving in the right directions.  This is what the LEDs need to compete against.

[LED Growlights]

motobroker is a person sorry lol
i would like to see some pics of the procyon growing something
there are vids on youtube of a guy using 60w to grow he used red and blue to begin with they were small plants but they grew
then he used white for growing and he said he was gonna use the red blue for flowering  62w and the plants dont seam that bad for that light power
http://youtube.com/watch?v=Grzv-HzTAUU
why are deep red leds so mutch? 660nm

[LED Growlights]

i also found these 3w beauties
not sure of the make any ideas?
or price but they have most colours and are screw fit





All feature 60 degree beam angle)

[BVnursery]

Seemed to have touched a nerve or two ...

Until the spammers made a hobby of our forum, member details were available.
My email is     bvnursery@gmail.com

Kinnza is certainly one of the most knowledgeable and best educated on the subject Ive had the pleasure of any discourse with.  He and I differ only slightly on our perspective and for different reasons.   The 660nm + 700nm duo is written up in an ever growing number of PHD level papers.

Ive grown a huge variety of plants hydroponically for years.  I use a very simple basic proven formula that has worked quite well with zero additives.   I prefer that type of approach.

Plants and leds are NOT about color,  plants use very specific spectrums in their conversion of light to growth methodology.

100 watts of properly designed led arrays will make trees from chive seeds.  The operative there is ...  P R O P E R L Y.   That doesnt mean a parallel design nor huge numbers of power hogging 12V strings.  A red ie 2.0Vf led can very effectively be run in strings of 46 or so with a power load of 20ma and a 100v supply.  The difference allows for PS losses and regulation.

I look often...  and as of yet... I have not found one unit in the marketplace today that I personally would spend 3 bucks on at a yard sale.

Plants will grow with 2 spectrums, plants will grow under incandescent.  Do I want to waste my power use on a system that provides less than optimum for plants? No I really dont care to do so.

620nm is not a direct plant spectrum.  Plants derive benefit from 620nm due to the overlap of spectrums not the 620nm base line.  That means if you look at any spec sheet by the time 645/660 is achieved,  the output is down to the ~20/30% range.

Having source each of my leds individually I very, very freely grant that finding affordable specific spectrums can make kitties out of a female dog in heat...  (cant swear in here LOL )    Time and effort pays off there.

At the risk of being dumped on..  I will state that in the world of using leds for plants, wattage is my very very very least looked at spec.

My demands...which are met... are for S P E C T R UM,  output and view angle.  My baseline demands are for specific packages and If so those are already knowns.

As of today, the field is quite young with much to learn.  The fast buck artists as the mentioned brand is.. are there only for the money.  They have done no plant research only market research and have realized there are a huge market of people who want an instant fix and have the money to waste.  Scammers have no issue in taking money.