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DIY LED FIXTURE

I'm going through the musings of putting together an LED lighting system on the cheap. A much prior comment was: "The ideal LED to use is 5w and above, 10w really if you could find them but i'm sure they would be very pricey."

You can do it on the cheap if you are not fussed about coloured chips.

You can buy 10W 900lumen chips for around £1.30 each (US $2 a piece). Run a parallel string of 10 of these on a AC 220V to DC 12V 100W LED driver (costing £10 $16) (& need at least 10A wire at the terminals of the driver). I personally wouldn't fuss over LED reflectors as chips all point downwards (in contrast to CFL or HIDs) and you want the light to diffuse rapidly as you keep the LEDs close to the plants anyway.

Next, the problem is with heat dissipation. I'm not sure what proportion of energy is dissipated as heat, but guess it is in the region of 40-70%, so the question is, could you get away with a heat sink and or are fans necessary, I need to go back to my heat transfer notes from engineering at uni. These come at £2 a piece ($3.20 US). Or alternatively, would a nice cheap C section do instead, as shown before?

Either way, add some wires, plugs, fixings and base plate, from other cheap sources and it should cost little more than £50 for a 100W - 9000lumen grow light board and if you can do away with heat sinks, this could cost as little as £30 or £35 so $50-$56.

I have never done anything like this before or studied electronics since school physics so could someone with some knowledge say if this is feasable?

Here are the parts I am considering:

10x 10W LEDs
LED driver
heat sink
 
The purpose of using led, as i learn from various source's also from reading post made by smokemaster is to tune in to wavelength needed by the plant to grow, there are two main stage veg and bloom, if you are sure that a 10 watt cool white is providing the plant what they need to veg and bloom then go ahead, but i recommend doing more research on this matter, or PM smokemaster like i did. CMIIW

Note: cree is more efficient then this Chinese led. Your link is way more expensive, you could go here http://www.fasttech.com/category/1699/flashlights--lasers, way cheaper, on checkout use coupon LAUNCH, get of 5% from your order. (I'm kinda flashlight freak)
 
I agree with the idea that coloured led's are potentially better in that they do not emit any useless green light, but unfortunately 10w red/blue led's are around 4 times the price so not a financially efficient option at 10w. The 3w colour leds's are better value, but at £0.20/W this is far more expensive than using white 10w led's - £0.13/W.

I would be interested to know how the PAR compares between coloured and white led's because while white wastes some energy producing green light, the luminous outputs are much higher - 110 lumens/W for cool white compared with 60 lumens/W for red and 35 lumens/W for blue (cree's xlamp XP-E datasheet), I still imagine coloured led's are better, but by how much?

In terms of china led's vs cree, yes cree are definately better, but are significantly more expensive, my other concern is that the performance specs on eBay may be higher than in reality (a common Chinese sales technique). I'm a little confused with the website you linked in, the cheapest 10w led's are $4.71 each compared to $2 each in my link (£1.30), so from a performance/price comparison it doesn't seem to weigh up. However if using 3W diodes instead of 10w ones means I can get away without a heat sink on a c section tube, then that actually could be much cheaper. Need to consult my fellow engineering PhD friends.

My focus is producing something good at the lowest price possible. I appreciate the input.
 
My main concern (aside from the colors) would be running the LED's in parallel. I can't remember the details but generally, due to small differences in forward voltage you run the risk of blowing the whole bunch. At 10-12v each, I'd consider running them directly in series off 110v through a rectifier and with a simple current limiting circuit.
 
You are absolutely right about the pricing, i always see £>$, lol.

I'm not expert but, usually red led is best to count in radiometric output, Chinese red led tend to have other stray color in their led. Color Efficiency, interesting, never have thought about that.

If you have die hard fish lover or flashlight aviciado friend you wont have any trouble finding used ( 6mo -1y ) quality led, like cree, luxeon, chinesse etc, because sometimes they got bored, buy to much or other funny reason, i can have XPG R5 (3000K-6500K) or XML (3000K-6500K) for like $1 - $2.5ea price range. (they use 700ma driver and good heatsink 35-40C max temp), so i guess there's much left that i can squeeze.

Your setup is similar with http://thehotpepper....ling-the-blues/, or you can ask that to the person yourself, hes UK to.
 
FInally bought the cpmponents for an LED fixture (mostly from china so imagine it will be a while before it all arrives). Unfortunately, I've gone for red/blue 3w leds after all as I'm kind or sold on the monochromatic principle, and will just see how it goes. Also I bought 620nm red led's as they were half the price, which is fine for chlorophyll b but not optimum for chlorophyll a (660nm is optimum) and a/b ratio is usually approx 3:1, althought the 660nm leds were about twice the price. oh well.

I changed my mind on the lenses; I think they can be a good idea as narrowing the dispersion of light will mean higher intensity and less need to keep the LED's close to the leaf canopy.

I have one question about manufacturing, how do you attach the LED's to the aluminium platform? Heat conducting tape or screws and heat paste? I imagine the former will be much easier, just wondering?

Overall cost = £58 for 90W (30x3W) 20red and 10 blue
 
I recommend everyone thinking about building an LED light to read this article: http://aob.oxfordjournals.org/content/79/3/273.full.pdf

The short answer is...peppers grown under just red LEDs showed noticeably less growth than those grown with supplemental blue lighting. So plan on adding some blue or cool white LEDs to your fixture.
 
Ah finally a proper journal on LED grown plants, should have looked for something like this a while ago. Will have a good read! Thanks amps.
 
jonnyb said:
FInally bought the cpmponents for an LED fixture (mostly from china so imagine it will be a while before it all arrives). Unfortunately, I've gone for red/blue 3w leds after all as I'm kind or sold on the monochromatic principle, and will just see how it goes. Also I bought 620nm red led's as they were half the price, which is fine for chlorophyll b but not optimum for chlorophyll a (660nm is optimum) and a/b ratio is usually approx 3:1, althought the 660nm leds were about twice the price. oh well.

I changed my mind on the lenses; I think they can be a good idea as narrowing the dispersion of light will mean higher intensity and less need to keep the LED's close to the leaf canopy.

I have one question about manufacturing, how do you attach the LED's to the aluminium platform? Heat conducting tape or screws and heat paste? I imagine the former will be much easier, just wondering?

Overall cost = £58 for 90W (30x3W) 20red and 10 blue
Click to expand...

Sold, let see how it goes, (please built your own separated thread) my saving isnt enough yet to buy the led (only cost me $0.75/pcs), i'm going to use the 1watt, as it run cooler and easily spread, although i'm still waiting and encouraging my friend to sell his unused 660nm luxeon es for $1 a piece :pray:.

I'm not going to use lenses, lens reduce light output as i heard, cmiiw on this.

budget wise i'd use this https://dx.com/p/fuj...rease-like-4579 u can stick and un-stick it, or screw + some good silicon grease is the best.
 
amps said:
I recommend everyone thinking about building an LED light to read this article: http://aob.oxfordjou.../3/273.full.pdf

The short answer is...peppers grown under just red LEDs showed noticeably less growth than those grown with supplemental blue lighting. So plan on adding some blue or cool white LEDs to your fixture.
Click to expand...

Mine all grow towards the blue light, I've added more blue than red.

jonnyb said:
Ah finally a proper journal on LED grown plants, should have looked for something like this a while ago. Will have a good read! Thanks amps.
Click to expand...


http://thehotpepper.com/topic/34744-bluemeanietsis-late-to-the-game-glog/page__st__40
 
These wave lengths (below)work for me so far.
I've been playing with LEDs for several years.

I grow ONLY Peppers,nothing else so if you are growing other stuff I don't have a clue...

Something I've found is just using from 440nm and 470nm Blue and 625nm and 660nm red wasn't as good as using every LED wave length between 420 and 475nm and 615-675nm red that I could find.
LEDs don't only put out the rated wavelength.A 660nm LED puts out 50%+ of 660nm,not 100%660nm.
100% is impossible due to imperfections in the coating ,voltage and MA. differences between LEDs.

I think that the Cheap Chinese LEDs are actually better because they put out probably closer to 51% of their rated wave length and the rest is usually slightly higher or lower wave lengths.
Anything that gets me as close to all the plant usable wave lengths that the sun puts out is great in my opinion.

I also don't think there is a need for yellow or white LEDs in a grow panel.
If you use a CD to check out the wave length bands your panel puts out you'll see a lot of other wave lengths like white,yellow green etc are there also already.

I personally think most of the stuff people/vendors is crap - if you can't dazzle them with brilliance baffle them with b.s.

Tons of the crap they post is stuff that only works in lab conditions or whatever and is taken totally out of context.

Like LED data sheets that are giving you PULSED test results that if you used the MA and volts they say,you'll let the magic smoke out of a lot of LEDS real fast.
Your 100,000hr life will turn into 100,000 min.

I pretty much go by what my plants tell me they like or don't like.
I see no difference in budding in peppers using more high red,low red high blue,or low blue.
I do see more budding if I cut the nitrogen.
I do see Manzanos love more 660nm than 625nm.
I don't think Peppers are wave length specific like some plants are to make them bud.

I think the different peppers might like different mixes of wave lengths due to the genetics of where they grew to become what they are.
Mountain peppers or jungle types might have evolved to like different light than say a desert type or whatever.

One thing that is really unpopular these days is 1Watt LEDs.

Since I try and get as many wave lengths PER Panel I like 1 watt LEDs.
I can place 80 or so on a 16in. X 16in sheet of 1/8 in. Aluminium and not need cooling but still get tons of lumens.
I don't buy into the stuff about a 1 watt 80 LM. Led as being crap compared to a 80LM 3 watt LED.
I started out with 3 watt LEDs a few years back and see no difference in my plants between 1 and 3 watt LEDs.
3 watt LEDs needed cooling , had to be spaced farther away(=don't overlap as many wave lengths) and were 3X what I can buy 1 watt LEDs for.
I don't have a clue about 80 lm from a 1 watt LED sucks compared to 80lm from a 3 watter.
Then there is the fact that 5 watt+ Leds are just grouped LEDs to add up to 5Watts.
Some 1 watt LEDS are 3-5 separate Diodes in 1 LED.

Say I get 80 , 1 watt LEDs on my panel.That's about 6400Lm at probably about 12- 18 in. with a wide angled LED+/-.
Since 3 watters need more spacing,lets say I get 60 on the same panel without frying them with heat...That's about 4800LM with less overlap because the LEDs aren't as close together.
So which would you rather have,6400LM of more wave lengths over lapped or 4800 of less wave lengths overlapped?

My plants told me they liked the 6400 Lm mix better so far.

Then there is the crap about penetration...
I don't care what source of light you use,if you are giving your plants what they like they grow thick canopies.You will need to add vertical light or trim off shade leaves to get branching after the canopy gets nice and happy.

I don't believe the stuff about super lumens from higher watt LEDs.
Ya ,I know,it's on the internet so it HAS to be true...
A lumen is a Lumen,a measure of light period.
Just like the guys who use watts(as a measure of electricity-Volts X amps.) to try and say their stuff is better than other stuff.
They miss represent Watts.
With old screw in bulbs a 100watt bulb ALWAYS put out X amount of Lumens.So watts was a standard for measuring light output.
BUT with about ANY light source these days Watts means nothing.
Only how fast your meter spins.
Screw in bulbs that are equal to old 100 watt bulbs only use 78 watts now.
Same with any other light source.
Fluoros , halides etc. are all getting more efficient so from day to day Watts -used as they do in advertising , means less and less as far as what you bought for a light source...
YES watts can be used in other ways,BUT it is mainly used as a measure as far as V x A -how fast your meter spins.
It's MOSTLY miss represented as a sales tactic.

As far as optics go,I don't see a big enough difference in using them,in general.
Actually they cut down on LED output as far as I can tell in general.
They do LOOK neater on a panel...But my plants don't care about my ugly LEDs.

The loss of Lumens and wave lengths that can't get past the lens seems to not justify the expense-SO FAR.
I've only played with lenses on 3 watt Leds and it was better to use the LED alone than use optics that made my 100 Degree angle LEDs into 60 degree(if I remember right.

Once LEDS get higher in Lumens and the lenses allow more wave lengths and Lumems through them they might be an option.
Right now I see too much loss of wave length and lumens to justify the cost.
I'll stick with doing what I'm doing.
Using a gazillion 1 watt , cheaper LEDS with more wave lengths per panel (of the same size.

But with ANY light source,they ALL have their uses and are great in their own specific ways to use them and according to the growers needs.



Copied from another site:

[background=transparent]a mixture of the colors of the visible spectrum. Here is a summary of wavelengths (nm). If you are building your own LED Grow Lights it may be of help when selecting LEDs for your project.[/background]

[background=transparent]200 - 280 nm UVC ultraviolet range which is generally harmful to plants. LEDs in this spectrum are non-existant or very expensive.[/background]

[background=transparent]280 - 315 nm Includes harmful UVB ultraviolet light which causes plants colors to fade. UV LEDs in this range are now available and coming down in price.[/background]

[background=transparent]315 - 380 nm Range of UVA ultraviolet light which is neither harmful nor beneficial to most plants.[/background]

[background=transparent]380 - 400 nm Start of visible light spectrum. Process of chlorophyll absorption begins. UV protected plastics ideally block out any light below this range.[/background]

[background=transparent]400 - 520 nm This range includes violet, blue, and green bands. Peak absorption by chlorophyll occurs, and a strong influence on photosynthesis. (promotes vegetative growth)[/background]

[background=transparent]520 - 610 nm This range includes the green, yellow, and orange bands and has less absorption by pigments.[/background]

[background=transparent]610 - 720 nm This is the red band. Large amount of absorption by chlorophyll occurs, and most significant influence on photosynthesis. (promotes flowering and budding) The ratio of red (660nm) to far red (730nm) in sunlight is about 1.2:1[/background]

[background=transparent]720 - 1000 nm There is little absorption by Chlorophyll here, but Phytochrome uses a nice portion. Flowering and germination is influenced. Near and above the higher end of the band is the Infrared spectrum, which can also be heat and could cause elongation or affect water absorption/transpiration.[/background]

[background=transparent]Many of these plant pigments have dual wavelength peaks that can be activated with led light combinations:The visible colors of light from shortest to longest wavelength are: violet, blue, green, yellow, orange, and red. Ultraviolet radiation has a shorter wavelength than the visible violet light. Infrared radiation has a longer wavelength than visible red light. White light is[/background]

[background=transparent]Beta-carotene 450nm 480-485nm dual peak[/background]
[background=transparent]chlorophyll a 430nm 662nm dual peak[/background]
[background=transparent]chlorophyll b 453nm 642nm dual peak[/background]
[background=transparent]phycoerythrin 590nm single peak[/background]
[background=transparent]phycocyanin 625nm single peak[/background]
 
Smoke,

What sort of LED controller do you use that can handle 80 of 'em? Any particular resources you'd recommend for sourcing 1w LEDs?
 
I use LM 317's and resistors for each string of LEDs.

Not the best/easiest/efficient way but I can semi control LED outputs per string changing voltages...

LM 317's need heat sinks and 1 computer fan per board.
I use 3X4in. perf boards for the regulators.
I run the computer power supply (12v,12amp. or 24 volt,2.5amp.) supply into a box that holds 13+/- resistors and LM 317's.
I read that you can use other regulators that put out less heat and are more efficient but since I spent the $ on 317's I'm using them.
If I used drivers I'd have no control over wave lengths of the different strings.
Volts = Wave Length , MA. + Lumens.
As I wrote above,my goal is as many wave lengths per panel as I can get.
A driver or 2 would only give me possibly 2 different wave lengths-not counting the differences just between LED lots etc.

I buy a LOT of different Lots of LEDS just to get as many different outputs in wave lengths as I can from the cheap LEDs I buy.

As far as Vendors.Unless you buy hundreds at a time,like I did,you can't bargain.
BUT if you want 200+ combined the Chinese Vendors will cut their prices a whole lot.
Go to Flea Bay and find the cheapest price you can.
Offer all the vendors to buy from them off of E Bay(10+%savings).
Then tell them another vendor is selling the LEDS you want for 30% less than they are but since your buddy purchased LEDS from them you think they might be a better soource so if they can beat the lowest price you'll buy from them...
LIE LIKE A DOG on a cool cement floor in the summer. LOL

I got a lot of 1 watt star and 10mm LEDS and LM 317's for about $.50 each + I had them add free resistors and assorted other stuff I wanted.
But I bought several Thousand LEDs - 10mm and Stars.
I mix stars with 10mm LEDS.
Stars are lesser Lumens and wider angled where 10mm are brighter and tighter angled.
10 mm don't come in some of the wave lengths stars do and visa versa.

In general I use stars horizontally and 10mm vertically on my 4ft. X 18in. X 20 inch shelves.
3X -16X16in. star panels above and 4X -7in. X 12 in. 10mm in back and 1- 7inX12in. panel on each end.

I get really tight plants that branch early-in general.

No pics.Still playing around with my panels.
Right now a Demon Hab has taken over my shelves.

MY WAY THAT I SET UP LEDS MIGHT NOT BE RIGHT FOR YOUR USE.
I DO grow a couple plants for seed indoors.
YOUR MILLAGE MAY VARY.
I AM NOT AN EXPERT AND ONLY KNOW WHAT I THINK WORKS BEST FOR MY GROW.
I ONLY KNOW WHAT HAS WORKED FOR ME.

Everything I've tried has been geared towards getting super starter plants mostly BUT I do grow a few indoors in my Kitchen.

YA I wasted a lot of time on crap that was posted by EXPERTS on the internet that sucked.

One good thing about LEDS is you can just rework stuff to use in different ways to make nothing go to waste.
I started out playing with CHEAP 5mm LEDS to play with Lumens and wave lenghts.
Went to 3 watt stars , then to 1 watt stars-years ago.
1 watt LEDS (10mm and stars) are what I'm using now with the better results-for MY grow setup.

Don't try to compare Halides etc with LEDs or any other light source.
You can't put an LED 3ft away from your plants and expect them to work the same as a higher Lumen light source.
At the same time,I used/needed 2000+ lumens of Fluoro light to grow sprouts where an LED panel in lessor Lumens,in the right wave lengths keeps my starts a LOT happier.

Like Clint Eastwood said-A Mans gotta Know His Limitations...

I like LEDS better for what I use them for than any other light source I've played with.
Never played with Halides.Too hot for my windowless grow area.
T8's are also too hot.T12's were great in 3200LM at between 5000k and 6500K.
T5's are about the same price as making my own LED stuff.
With LEDS I can play with specific wave lengths,A BIG + in my book.

I wouldn't EVER buy a commercial LED panel.
You don't know what you'll get and they aren't cost effective in general.
You won't know if it is cool until the warranty is up...

Early LED setup using stuff I scounged for the Fan/LM317 box.

IM004532.jpg


Stars

Picture001-10.jpg


5mm LED toys-early experiments with 3X4 perf boards-125 LEDs+/- on sprouts in shoebox/99 cent store boxes.

IM004336.jpg


IM004335.jpg


Kitchen Plants

PICT1908.jpg


PICT2126.jpg


PICT2116.jpg


PICT2175.jpg


IM004983.jpg
 
My point is THAT IF you use LEDs correctly - according to their limitations you can get some great results.
Don't buy into all the crap that the internet experts post.

Nothing wrong with other lighting systems if they work for you.
Just don't buy crap from vendors because they seem to talk real purdy...

More $ doesn't mean better...More BS in the add doesn't mean better.
It usually means they thought they needed more BS to sell their product.

There are vendors out there that sell some good stuff,I can't afford their products...
 
smokemaster said:
My point is THAT IF you use LEDs correctly - according to their limitations you can get some great results.
Don't buy into all the crap that the internet experts post.

Nothing wrong with other lighting systems if they work for you.
Just don't buy crap from vendors because they seem to talk real purdy...

More $ doesn't mean better...More BS in the add doesn't mean better.
It usually means they thought they needed more BS to sell their product.

There are vendors out there that sell some good stuff,I can't afford their products...
Click to expand...

The smokemaster has spoken...
 
I'm not going to argue with smokemaster as i've been there and done that but you guys really need to do some more research. There are specific reasons why all of the big LED light manufactorers are using 5w or better LED's in there lights. They are simply better than 1w leds. Yes, you can make 1w led lights like smokemaster and have 50 different led boards plastered all over the place at every angle to grow your 1 single plant. Or you can have 1 5w led light that does the same thing and grows 10 of them to the size of small trees. I've posted multiple pictures of my setup using commerical LED lights with plants that are almost as tall as me. My plants are huge with pods all over them. My plants have been putting out pods all year long. So to say that 1w LED's are better than 3w LED's or 5w LED's is just straight wrong. The purpose of using the higher watt LED's is for output reasons. With the higher watt LED's w/lens you can focus the light and it requires less LED's with the light traveling farther and penetrating the canopy better. This means you can have the lights at a farther distance from your plants allowing you a better coverage area. So I guess what you really need to ask yourself is, do I want to grow 1 plant with 1w led's. Or 30 plants with 5w LED's.

My new plants for this season, yes this is roughly 30 plants under 2 small led lights. Notice the distance I have the lights from the plants? I could probably add 20 more plants if i wanted.
WP_000673_zps5f9d53de.jpg


In my opinion, your best bet is 3w LED's with 90 degree lens. This gives you a good focus of light with a decent amount of coverage allowing you to grow a decent amount of plants to a very nice size without breaking the bank. As far as the mix and match of led colors. Smokemaster has it dead on in that aspect. Red and Blue LED's of every nm level you can. It has been proven again and again by many sources that plants only use the red and blue spectrum. Red promotes blooming and Blue promotes Veg growth. So you will want to add a specific amount of each based on that. Using green or anything else is simply a waste. The plant may use a tiny bit of it, but it simply just doesn't use enough to warrent adding them to the light.
 
I only plan on growing 4 plants indoors, the fact that 5w allows me to grow 30 does not balance out the cost of the leds to do so, so in your opinion - Yes I'm fine with 1w/1plant ;)
 
Interesting debate going on here.

I have to aggree that the latter system is far neater, yet working out in terms of price efficiency, there is no way around it, 3w are the most cost effective solution for monochromatic sources.

you can pick up cheap heat sinks here too , although as has been pointed put there are many ways of removing heat.

After reding a little about LEDs it, I found out monochromatic LED's are more efficient than white LEDs, although I'm still a little confused about stated outputs (personally I think they are making them up on ebay).

White LEDs are actually blue LEDs coupled to a yellow phosphor that absobs blue light and re-fluoresces it at a spread of longer wavelengths (Stokes Shift).

This means that some energy is lost in non-radiative decay and that the spread of frequencies means that some light fluoreses in the non-photosynthetic regions (yellow-green and IR).

Here is a diagram that shows the normalised spectral distribution of various coloured LEDs: the white contains blue (440nm) and a secondary distribution of wavelengths, whose's peak is at ~560nm which is yellow-green!

led_spectrum_distribution[gsc].jpg

Having said all this I am not sure of the luminous efficiency of red LED's but blue LED's therefore should be more efficient than white, and white will produce far less red than a red LED so it seems red and blue are the way to go, (ignoring the cost implications).

Also thought I'd add this, while I'm not sure how much photoresponsive similarity a daisy has with a pepper plant, I thought it looked interesting:

led_light_comparison[gsc].jpg


this all came from this address: http://www.greenergy...711pcs-red.html

I apologise if this is too much theory, but there you go.
 
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