NEW LED PENDANT FOR PICO

[cdelicath]

I need to make a light for my new pico tank. It's about 1 gallon.

 

 

I have a heatsink I would like to use:

3" X 2"

 

I want to use this heat sink with no fan as a pendant.

 

First off, is this even possible?

I do have a fan bezel for it that can be used if needed but I would like to keep this as quiet as I can.

 

I don't need a lot of light "low light corals".

Depth 8" light to sand.

 

I was thinking 2-4 LED's

I would like a 20K color

optics for better light dispersal?

My budget on this one is low per the warden.

 

A build list from one of you pro's is what I am looking for.

I'm not sure of how many LED's I need ballasts and stuff like that.

 

I am also willing to do a detailed writeup of the build and part's list if I can get some help with this.

 

Thanks Guys

[evilc66]

If you are going to use no fans on that heatsink, it's got to stay open. If you wrap it in something to make it look better, make sure it has lots of openeings for airflow, especially at the top (heat rises).

 

If you want a 20K look, you could do three royal blues with a single Q5 or R2. Place the royals in a triangle, and have the white in the middle, but get them fairly tight together. Get two drivers (Buckpucks are prefered) so you can change the brightness of the individual colors to tweak it to what you like. Get the 1000mA version for the white, and the 700mA version for the blues. A 12v power supply capable of 2A will be enough to run all of this.

[cdelicath]

I am searching through the forums trying to find links of where to get all this stuff. any places you recommended?

 

Also what about optics

[Splumph]

For 20k I'd say 1 white and two blues. Since you're on a budget, you could mount the LEDs to your heatsink using thermal epoxy.

You probably are going to want to use a fan with that heatsink, low flow 80mm fans are quite and work well. If you do not want to dim, than you can use this power supply for the blues, and this for the whites.

 

The whites would be underdriven (700ma) I can look a little better for a 1LED 1000ma power supply when I'm not at work. Keep in mind that anything ordered from DX will take a while to come in, because it's coming out of Hong Kong. This stuff should keep your project under 50$, not including the tools (soldering iron).

 

With such a small tank, no optics will be needed.

 

^^I noticed evil got to it before me, go with his advice..lol.

[cdelicath]

$50 is about where I want to be give or take.

 

I will order a quiet 80"mm fan I'm sure it will workout good.

 

will I need a separate walwart transformer for the fan or can i power it all from the same transformer?

 

also is there anywhere in the US I can get all the parts?

[Splumph]

If you decide to use buckpucks you can get everything from www.ledsupply.com or www.luxeonstar.com. Prices are a little higher at luxeonstar, but they ship quick. IF you go that route, then definitely go with the 3-1 royal blue to white ratio, instead using this white.

 

Just forget about those power supplies from dealextreme, and go with a laptop supply (evil knows the site, I can never remember it)

 

Going this route will bring the price up a bit. (probably to 80-90$)

[evilc66]

You can get everything from LED Supply if you want. They carry all the parts, except the highest bin white they carry is a Q4 (200lm as opposed to 220lm with a Q5, and 245lm with an R2). Will set you back $89 plus shiping.

 

1x Q4 White

3x XR-E Royal Blue

1x 700mA Buckpuck (dimmable w/pot)

1x 1000mA Buckpuck (dimmable w/pot)

1x 12v, 3A Power Supply

 

You can save a few bucks if you only use one driver (the 700mA one), but you loose the ability to change your color temp.

 

The fan will be able to run from that power supply. If you want a super quiet fan, look into the SilenX series of fans. Most are 14db, which is quieter than a whisper. Newegg has the best prices on them.

[rickjg]

You can get everything from LED Supply if you want. They carry all the parts, except the highest bin white they carry is a Q4 (200lm as opposed to 220lm with a Q5, and 245lm with an R2). Will set you back $89 plus shiping.

 

1x Q4 White

3x XR-E Royal Blue

1x 700mA Buckpuck (dimmable w/pot)

1x 1000mA Buckpuck (dimmable w/pot)

1x 12v, 3A Power Supply

 

You can save a few bucks if you only use one driver (the 700mA one), but you loose the ability to change your color temp.

 

The fan will be able to run from that power supply. If you want a super quiet fan, look into the SilenX series of fans. Most are 14db, which is quieter than a whisper. Newegg has the best prices on them.

Hey evilc66

 

Not to high jack this thread, but I'm setting up an 0.7G freshwater planted pico & want to use one 3 Watt MR16 12 Volt lamp and I already have a highpower 12V - 4.2A power supply from an old chiller.

Will this power supply fry a 3 Watt lamp or can you run LEDs overpowered?

 

THANKS

[evilc66]

Those lamps should have internal regulation. Hook it up to 12v and rock and roll.

 

PM me pics of that when you get it running. I'd like to see what you are doing, as I'm into planted tanks too.

[coralcor]

dang evil you no waht ur talkin about i was readign all that and i was like "hu o no wate hu" lol

 

ill haveto show this to my dad c if he understands lol

[evilc66]

 

Electronics, and especially LEDs, have been a long standing facination for me since I was a kid. It's come fairly natuarally for me, but I do a lot of research and reading into LEDs, their theory and their practices and implementation. I try and know as much as I can about LEDs (and lots of other things) so I can help you guys out as much as possible, and even help myself at times too

[cdelicath]

Hey evil will a 1.5A power supply work

If not I have a computer power supply sitting here also it outputs 14A at 12V

 

Also when getting the buck pucks Should I get the 700MA dim or the 1000MA dim

My thought is the blue would be the one I want to dim right?

Then I can just get the regular wired 1000MA....

[Splumph]

Just pay the little bit extra to dim em both, its good for acclimating corals to the light.

[cdelicath]

Just pay the little bit extra to dim em both, its good for acclimating corals to the light.

 

Getting down to the nitty gritty with the price.

That 5.00 pays for the shipping

Your probably right though

[cdelicath]

Here's my order:

 

1 Cree XR-E Q4

Star LED $8.49

 

3 Cree Royal

Blue XR-E

Star LED $25.47

 

1 3023-D-E-700P

Wired

BuckPuck,

700mA Output,

DC Powered w/

Potentiometer $19.99

 

Subtotal: $53.95

Shipping: $6.00

Tax: $0.00

Total: $59.95

 

I have a 1.5A power supply I am hopping I can use since I am only running 1 buck puck now.

I am going to try what I ordered and add more LED's If I need too.

 

Still have to get a fan here locally and figure out an enclosure.

[davidr2340]

Getting down to the nitty gritty with the price.

That 5.00 pays for the shipping

Your probably right though

DO IT!!! I'm wanting to live vicariously though this build!!!

[cdelicath]

And so it begins

Waiting for parts. . . .

[evilc66]

Well, I've already answered this in your PM, but I will explain for clarity for others.

 

4 LEDs at an average forward voltage of 3.7v will get you to 14.8v. Now add 2v on top of that for proper operation of the driver and you are at 16.8v. You can get away with a 16v power supply because they are usually a little higher output than advertized, but to play it safe, a 24v power supply will work just fine. You can't get a power supply to match the total forward voltage, as it can change as the LEDs run.

[Splumph]

What I find real funny about this whole LED thing is that everyone comes in saying they just want to accomidate mushrooms, zoas and other softies, and we always set up SPS lighting systems. You wouldn't save much, if any money making a lower end unit, and you would just be dissapointed in the end. I've been wanting to throw together a small array for a desktop tank at work, so I will be watching to see how this turns out

[rickjg]

Those lamps should have internal regulation. Hook it up to 12v and rock and roll.

 

PM me pics of that when you get it running. I'd like to see what you are doing, as I'm into planted tanks too.

Will do ... 0.5G ZEROedge type Pico w-LED Lighting

 

-Rick

[evilc66]

What I find real funny about this whole LED thing is that everyone comes in saying they just want to accomidate mushrooms, zoas and other softies, and we always set up SPS lighting systems. You wouldn't save much, if any money making a lower end unit, and you would just be dissapointed in the end. I've been wanting to throw together a small array for a desktop tank at work, so I will be watching to see how this turns out

 

You're right, it doesn't cost much more to get it to this level. Although, half the issue is the intensity of the LED itself. Even a single LED has quite high PAR, just over a small area. It just doesn't cost much more to go from 1W LEDs to 3W LEDs. The drivers don't cost any more, and you still need a heatsink. At least with something like this you never have to worry about upgrading when you do decide to go sps. You just turn it up!

[cdelicath]

The part's are on their way and I hope to start work and write up this weekend. I found a 16v 4.5A laptop PS also.

 

What details do I need to know about connecting the buck puck, PS, LED's and so on.

Any tricks to soldering? wiring combination's?

 

Here's my plans:

 

[evilc66]

The way you have the LEDs marked for connection is in parallel. You want them in series (+ - + - + - + -).

 

Another suggestion, and this is totally personal preference, but you might get better overall color if you have the white dead nuts in the center of the blue triangle, and get them tight together. The pcbs are hexagonal, so it will be easy to place them correctly.

[Splumph]

Looks like you have them wired in parallel, they should be wired in series.

 

^^beat me to it

[cdelicath]

That's what I thought when I looked at the buck puck PDF but I don't know how to read schematics.

 

so it will basically make a big loop right?