[fishman9809]

i am going to set up a tank, approximately 10 gallons, same size as the ADA 45p (18" long x 10.5" wide x 12" tall). here is my basic design of the LED fixture:

the LED color is going to be 6000k, aka cold white. 125lm per led, 1w consumption per. to get the same luminous output of a 36w PC bulb, use 15-18w of led.

here is the LED i will be using 15 of:

http://cgi.ebay.com/5-Prolight-1W-H...9200907QQihZ016QQcategoryZ66954QQcmdZViewItem

i cant find a heat sink or a power source to accomadate 350mA LEDs and about 55volts of the LED's. if you have any recommendations for heat sinks (even the ones that hold a single LED) or power supplies, lemme know, because ive been looking all day

also, do i need a DC or AC power supply?

tell me what you think of the project!!!

 

[Indignation]

I've been wanting to try something similar for a while now, but haven't had the time or money to pull it off. I'll be keeping a close eye on your progress!

As for your questions, Your link didn't work for me, but i assume you're using the pro light 1w luxeon stars. Here would be a good place to check for heat sinks. I would just call and ask a rep what would work for you.

Also, have you thought about tossing a couple red and blue LEDs? After reading about light spectrum and what plants need to grow well, I thought a few of each might gear the spectrum more towards plant-usable light. I think the white leds would balance out the "look" of the light. This is pure speculation, but might be worth looking into.

 

[fishman9809]

i fizxed the link. i am only using white because the ebay store i am buying from only lets you get it in packs of 5, so i cant just get like 2 or 3 like i would prefer.

i hope to get the total of this project under $100, just to show people what you can do with leds.

 

[Cory Keeper]

100% whites are fine for your application. But sadly your on a lower light level than alot of plants like. A minimum of 1 LED per 24 square inches is a good starting point. Though your 5 LEDs would probably grow your plants really well, I think your plants should be limited to low light plants. Or up the number of LEDs.

BTW, heatsink looks good.

EDIT: NM, I just noticed what you posted.

IMO those are probably junk LEDs, 9 Cree XR-E Q5 of 9 Luxeon Rebel LEDs would be better. I do not trust anything but Cree or Lumileds Luxeons. Crees are pushing 100lm per watt where as those probably only about half.

 

[fishman9809]

it seems i never updated this thread. this experiment is going actually to go on a vivarium which i'll set up soon.

 

[Cory Keeper]

yeah, after reading over the E-bay page, something to really really avoid. They are advertising over 100lm per watt, something not even the best crees can match, and super cheap as well. Really not worth the risk. Just go with Crees or Luxeons.

But I rescind my previous suggestion of LEDs, 5 would be fine for a vivarium since light penetrates air better than water.

 

[fishman9809]

going back to aquarium

gonna get 5 leds from that ebay page, but 3w'ers, but cree xr-e q5's can put out over 200 lumens, so its believable to me.

 

[Cory Keeper]

yes, but look at the price of the crees.

Either A: they are overating the product OR B: they are using really really cheap materials, which means much less life in them.

Also, as stated, not even crees get 125lm per watt, which is what those are stating.

And looking over it even more, I see 4 red flags.

1: 125lm per watt, no LED made currently gets that kind of efficiency.

2: "Due to the low value and profit selling on ebay, we do not accept returns of any kind." . " You understand you are taking a risk by ordering." That right there is a red flag, should be ringing all kinds of bells. DO NOT BUY

3: Prolight does not make Luxeon LEDs, Lumileds does. Putting a trusted name on a fake product is common scam tactic.

4: I found some 3w LEDs listed using the same EXACT specs except for the current, 700mA.

You can buy it, but don't be surprised if its not as bright as you think it is.

 

[fishman9809]

where does it say per watt?:

This is 5 pieces of White 3w LEDs mounted on stars.

Intensity: 110~125Lm
Viewing Angle: 120°
Forward Voltage: 3.2V~3.5V
Forward Current: 700mA
Color Temperature: 6000k

 

[Cory Keeper]

The link you posted above says 1w LEDs, and the specs say 1w as well, 3.2vx350mA (.350)= 1.12w, a little over 1w.

I still don't trust it too much.

 

[fwdixon]

It would be easier to set up using a DC power supply. AC could be used, but you would need a rectifier circuit, as LED require DC input.

 

[Muirner]

I'm looking on ebay right now for some High Powered LED's. I ran across a 10W LED here ebay

700lm is rated from this LED. With this in mind even with the higher cost of the LED, a 10G fixture wouldnt be unheard of in cost... or are these LED's advertising what cannot be achieved?

 

[Cory Keeper]

Its possible, it looks to be a high power LED, but its difficult to say its any good. For one, "white" could be any color spectrum, second, dunno who makes the thing so its hard to know if anyone else has had trouble with them.

For your standard 10g tank, 9 LEDs would be perfect, should give you tons of growth without any trouble at all.

 

[Qwertus]

What about these?
http://www.luxeonstar.com/luxeon-rebel-led-cool-white-lambertian-130-lm-700ma-p-165.php

 

[Cory Keeper]

yeah, those are fine, but if you order them, you will find they are not pre-mounted onto the stars, and soldering them on takes a special technique, a technique I am going to have to learn from the looks of it .

 

[Qwertus]

Those take way less space and cost a bit less than the ones your using too because it doesn't come with stars. Those stars are sort of like heat sinks i think. I just finish modding the psu into ~3v, ~5v and ~12v; the current on those lines are a bit high though.

I also have a few LEDs with these specs, are they any good?

Lens Colour : Water Clear
Emitting Colour: White Color
Intensity Typ : 110~120Lm
Viewing Angle: 120°
Forward Voltage : 3.3V~3.5V
Forward Current: 700mA
Colour temperature :6000k

 

[Cory Keeper]

I dunno about less space, unless you have experience in building/designing a circuit board, mounted to a heat sink.

And really, all thats need is 12v lines, current is regulated with drivers, either with DIY http://www.instructables.com/id/EK2XAPS11GEWOF2YSD/ or through something like a buck puck.

But yes, even if you mounted them yourself to a star, they could cost less than pre-mounted, just be forewarned that it can be tricky. Best method that I know is to melt a bit of solder on all three pads using a 15w soldering iron, then with heat gun (electric or butane, doesn't matter), apply heat to the underside of the star/base until solder on the led melts, with heat still applied, make sure LED is mounted correctly. Remove heat when satisfied, or before too much heat is applied and fries the LED. Check for continuity between positive and negative. If continuity exists, heat back up and move LED a little, repeat process.

Oh, one other thing, I wouldn't be worried too much about heat, some will actually BAKE the LED to get it soldered in there.

And Qwertus, depending on the costs of the LED, I would say it should work. To give you an idea, my 29g has 15 Rebels which emit 145 lumens @700mA. Color temp I don't think is near as important with LEDs as people make it out to be though.

 

[Qwertus]

What did you use as heatsinks on the LEDs and those NFET transistors? How many of those LED drivers did you have to make for all your HP LEDs? Any techniques for building something that I can mount regular 10mm LEDs on to the board but still can remove/switch them without soldering?(sort of like a bread board). I'm not sure if i will like the colors that why, just need an easy way of changing them if i dont like or get bored of one color.

I was thinking of superglue them on the circuit board then put thermal gel in the holes that have direct contact with the LEDs then mount the heatsinks directly on top. The reason for the board is because I have a few other 10mm LED circuits as moon lights (Blues) and Greens or Yellows for viewing. Viewing lights turn on and off by a clapper I did as a school project a long while back.

 

[Qwertus]

Does anyone know if LED drivers work with several parallel arrays? Or Does each array need its own driver?

 

[Cory Keeper]

Each string will need its own driver. And there really is no way to easily exchange LEDs without a bread board. And frankly speaking, if your wanting to play with the colors for your normal viewing, you will still want to use HP, they will last far longer. If you go with the Luxeon Rebels, they are fairly easy to solder. All you would need is a little bit of solder, some tweezers, a butane hot air soldering pencil (remove tip) and a set of Helping Hands (to hold the hot star). Its a bit tricky playing with SMD LEDs but its quite easy once you know how. I've also heard of the skillet method and baking method.