DIY LED lights
 

Does anyone have a link to a place that shows how to wire them up? In what series and parallel configuaration? What is the best LED to get and where to get it. What power supply and so on. Thanks for any information.

I probley should have said this. I am wanting them to take the place of my M/Hs on my reef tank if it is a good ideal and so on.

alot of people have thought the same things you have, but they saw the cost and decided to stay with their current light set ups and let companies develop LED lights.

I have heard I can build my own for $300. The LED lights for reef tanks are a new thing. Just like any market they will charge out the yazoo for something but becuase it is new. It is a well known marketing stragie.

Leds are very simple. You can put hundreds on the same curcuit. I just need to know the best led to use for the price. I know of a place I can get them VERY CHEAP but it takes them a month to get the order made and shipped over here.

sorry if this against any rules but i did a thread on LEDs along with other people.

[url]http://www.reefcentral.com/forums/index.php?showtopic=134394[/url]

i manage to build one less then $100. but its only about 20 watts of light.

im working on a new project that holds at least 15+ LEDs making it more then 40watts for my 7g tank.

Look, for a 120G reef, you'll need at least 500w of leds, so near 100 leds so at least 4-500$ just in leds.

Now you need lens, drivers, heatsink, fans, enclosure.

You are now close to 2500$

NICE. not what I was hoping. O well that deal is out the window.

For real, though, you could go and get LED's from Radio Shack. They sell in bulk "pure white" LED's that work out to about $0,75 a piece. I have a bunch of LED's that brighten up areas, you know like burning a picture, and for a few other things that I'm waiting for my patent on. Usually they are 5-watters that are best hooked up in parallel. That way one light out won't wipe out all the lighting. Also, I liked the lo-wattage ones. I was only sending about 24-volts to the top of the tank. FBN, I have some plans. If you want I could help you brainstorm.

Icefire: I'm wondering why one would lenses for an LED matrix to work. I understand that LED's are a "multi-directional", if you will, but everything that I did, including using them exclusively on a 20gal long, they were okay just by pointing them in the direction that I wanted light, and using some sort of reflection above. That looked so cool, Ill see if I can find a picture.

I have a 72g bowfront and would like to build a LED rod with about 4-5 LEDs in it. Any suggestions? I was thinking PVC and paint it black.

Do a google seach for LED wizard. it shows you how to wire them.

you can buy the leds from china for next to nothing. How does $0.18 each for some 3.4 volt ones. Here is a link... Also check out the other link with the board that would make ti easy to set up. So what do you think about the qualty? Think it would make photosynthesis happen? Even if they where only one watt each that is 1k watts worth of light. Not bad for $200 ? Haha

Ultra brightness and low power consumption
Long-Life if used appropriately (>100,000hrs)
Suitable for many DIY applications
1000 pcs of 5mm Clear type LED
Viewing Angle: 15-20 Degrees
Intensity: 15000-18000 milicandelas per LED
DC Forward Voltage (Vf): 3.2-3.6 (3.8v max) @ 20mA
Colour Spectrum: N/A



[url]http://cgi.ebay.com/1000-15k-mcd-High-Luminous-5mm-LED-Bulk-Pack-White_W0QQitemZ140189251981QQihZ004QQcategoryZ105796QQrdZ1QQssPageNameZWD1VQQcmdZViewItem?_trksid=p1638.m118[/url]



[url]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140150441205&ssPageName=MERC_VI_RCRX_Pr8_PcY_BIN_Stores_IT&refitem=140189251981&itemcount=8&refwidgetloc=active_view_item&usedrule1=CrossSell_LogicX&refwidgettype=cross_promot_widget[/url]


So,

dhesq, Did you say you want to brain storm with me? NICE I love project buddyies. Tell ya what you can do. Search out the most watts per $ led you can find. I will do the same. Also the power supply and so on. I want to go like 14k to 20 k. I like the blues =-). Lets try to build a system with 500 to 800 watts of output no biggier than 1 foot by 4 feet. For arround $300.


Do you think we can do it?

Can anone convert Intensity: 15000-18000 milicandelas per LED to watts?

Guys... I hate to burst your bubbles....

But 5mm LEDs are just not going to work. You will need to look into high output LEDs by CREE or SOUEL... they cost quite a bit more than $0.18 each.

You will need a constant current driver. Good ol resistors are not going to work that well.

Michael Bolton: That's the worst idea I've ever heard in my life, Tom.
Samir: Yes, this is horrible, this idea.

-Office Space :D

Have some links?

you need lens for the high power leds or you get 155 degre of lights.

Those 5mm leds have least than 0.07 Watts each.

Sweet, I am learning.

What kind of lens are you talking about? One to filter heat or radiation? Maybe something like a weilder's lens?

Drivers is what? the powersupply?

When you said "Those 5mm leds have least than 0.07 Watts each"
Is there a formula or is that just a educated guess? No sarcasm intended.

Thanks for the help. =)

Flybynight-

I see a high level of miss guidence involving LEDs.

First, the object is NOT to collect the largest amount of wattage, the object is to get the highest amount of light onto the corals as possible.

With LEDs, wattage and light are shockingly mismatched right now. We have CREE R2 leds that can generate 114 lumens/watt, while the majority of LEDs for sale on the market are stuck in the 30lumens/watt area.

This can mean that 200watts of CREE LED will create the same amount of light as 760watts of typical LEDs.

It also means that the higher surface brightness on the dice of the CREE chips can take better advantage of the optics/reflector placed around it to get that light into the water, as light that doesn't get into the water doesn't do us any good.

LEDs that would be worth useing are about $8/per LED, and you will need about 60 of them. You also need an optic for each LED, which costs about $1.50/optic. This puts you around the $500-600 range, which isn't bad. Now you need a large 1/4" thick aluminum sheet with fans on the back and about 5 x artic silver epoxy kits to mount the LEDs. Then you can solder them up in series chains of 3, and parallel these chains of 3 all together. A single good computer power supply 12v output line and a bucking type adjustable current regulator can be made to power them in a mostly safe mannor.

It's not impossible, but if you don't throughly research this sort of thing, you are definately not going to make it happen.


BTW- 5mm LEDs are rated at either 20mA or 30mA.
3.2vf x 0.02A =0.064watts.

As far as the terms you are useing I know them. It has been a while. I used them back when I had a car audio shop. I would wire large systems of speakers and so on.

Anyway, My research has began here. I want to do this because I love the ideal of something new and getting ride of my M/H for something that can do just as well for less heat and so on.

5 x artic silver epoxy kits You are saying I glue the leds to the 1/4" thick aluminum sheet ?

a bucking type adjustable current regulator

I know what a current regulator is but what is Bucking type?

When you say this

It's not impossible, but if you don't throughly research this sort of thing, you are definately not going to make it happen.

Are you saying I can do it if I do my research?


Last question. I am guess that these leds get really hot?

The LEDS generate a LOT of heat. Most of it is wicked away through the LED die (the base). This is what the big thick heatsink is for.

This is not a project for an electronics newbie. In theory the concepts are rather simple. However, in practice there are a lot of little details to get right. It will cost you about $1000 in parts and tools to even consider doing this right. Trial and error is certainly an option, but a costly way to learn with something like this.

I would suggest ordering a handfull of LEDs and getting a few electronics books and starting off very small. Get 1 or two high output LEDs to light. Learn how and why they work. Learn how they behave at different currents. In the process learn as much as you can about power supplies (constant current in this case).

Electronics can be a very rewarding hobby. If saving money is your goal, then this is not the project for you at this time :) If learning IS the goal, then you now have a place to get started.

Sweet, Sounds like a plan. I think I will start small and move up.

As far as being a nubie. I have messed with electronics from a small kid. If I have any problems with tools I would ask my older brother. He is so smart he is dumb Haha. At the age of 7 he built a am radio that looked like a pen. But, he could not even say his own name. When he was 12 he rebuild a motor on a car. But, he could not even spell his own name. He has High fuctional Autism.

Anyway, no problem is to big for me =-) I just have to remember (baby steps)

Those 114 Lm/Watts are if you run them at 350mA or 1Watts.
But if you drive them at max (4.5watts), it drop by half.

So it's either you drive them at max or buy more and run them at 350mA.

For his 120G tank, if we calculate that you need 3x250w MH normally (750W) and plan to use 500W of leds (leds are less efficient than MH, normally you would need more), if you drive them at 1W you need 500 leds at near 10$/each for R2 bin.
If you drive them at 4.5Watts, you need 100 leds but you drop at about 60lm/Watts.

Also, you need the puck driver that cost $$ each and you need at least 1 per 3 leds.

Icefire- You need to check your specs on the R2 again... At 800mA, you are still getting 95lm/w. If they were luxeon K2's, then you would be correct with that sharp of a droop in efficiency vs current. The new Cree's have a shockingly minior droop curve to about 800mA, then from 800-1600mA, it falls off like other LEDs. Note, 1600mA should only be tried by experts.

You are also way off on your lighting needs estimations. You only need 3x250w MH's on your 120 becasue the typical MH reflector is able to get less than 50% of the bulb lumens into the tank. Also, aquarium spectrum MH bulbs are around the <70lumens/watt range.

Due to the unique ability for LEDs to actually get a large amount of the light produced INTO the water (rather than making for a very bright warm canopy like MH), they only require making about 60-70% of the same bulb lumen numbers to match underwater par levels.
Due to CREE, they are finally able to make that light at reasonable emmiter efficencys.

You simply do not need 500W in LEDs. At 800mA each (roughly 2.5-2.8w depending on the indivdual chips Vf) that would mean 180 LEDs each making 250lumens. You would be generating about 45,000 bulb lumens, and likely getting 35,000lumens of those INTO the water. Most aquarium spectrum 250w MH can't get 10,000 lumens into the water even with lumenarc reflectors. Hell, most 20k 250w MH bulbs don't even make 10,000lumens at the bulb!

I didn't research those specific curve but one thing is sure, I didn't even found a PAR reading of a Solaris I4, so we can't really judge of the efficacity VS T5/MH.

Taking in account the 10% you loose with the lens, the water reflection/bla bla, we can only speculate,

The last time I looked, a good puck driver was around 30$ for 3 leds, if you use 180 leds as you sugested, with 10$ for the led/lense/star, 10$/led for the driver, plus the powersupply and heatsink fans, you are at least in the 3000$+