So after doing some research and owning power compact, metal halide, and t5 lighting fixtures, I have decided that I am going to dip into the LED side of lighting. This build will be for my 2.7 gallon pico refugium, in order to get some good chaeto growth and experience building LED fixtures. I am planning on building a very small LED light for the chaeto in the refugium first.

Here is the heatsink i settled on



The dimensions of the refugium are 6'' long x 2.5'' wide x 8'' deep
Could I get away without a fan on this since it is so small and will not have many LED's? There would not be an enclosure around this.
I am thinking two cool white LED's?
Is there anything else I would need to add to the list to build this?
I have read that 6500k is the best lighting spectrum for chaeto growth, will LED's provide growth?


LIST
Thermal Paste
2 x Q4 Cool-White Cree XR-E Star (Or should I go with the more powerful Q5's?)
Power Supply - (I need help with this, how many volts and amps will I need for 1-3 LED's?)
Buckpuck Driver 1000mA dimmable w/ potentiometer

i am sure evil will chime in on it sooner or later. have you seen the INTANK submersable fuge light? looks and works great! reasonable priced also. they are a site sponser. or look up stevieT on here.

yeah i saw those but I really want to get into LED's and I have heard those raise the temperature of the water a good bit

A 5W halogen won't add any appreciable amount of heat to a tank. But LEDs are still fun

6500K Q4s will be more than enough. Some of this will depend on how you plan on mounting some of this, but I think I'd go with the larger of the two flat heatsinks. If you are only planning on two LEDs, it's more than adequate. Don't know if I'd bother with the dimmable driver for this application. Why would you want to dim it? You typically want the most growth possible from macro algae. Faster it grows, the more nutrients it exports.

I placed an order with LEDsupply yesterday before I read your post

3 Cree XR-E Q5 Cool White LED's
1 Wired Buckpuck 1000mA dimmable w. pot
1 12V DC 3.0A Power Supply

1. I was planning on using the dimmable driver because I have heard these output an insane amount of light and I wanted to be able to control the levels. Also if I use this as a supplement to another tank in the future I would want to be able to control it for the corals and acclimation

2. Should I use two or three of the Q5's for this fixture? I figured three would give a better spread. Will i be able to get away without using a fan?

3. I also ordered Arctic Silver Alumina AATA-5G Thermal Adhesive to mount the stars because I do not have the tools, experience, or skill do a tapping setup.

4. I am planning on leaving the fixture open except for a piece of acrylic as a splash guard over the bottom (leaving sides open), and using some sort of clamp and lamp arms to clip this to the tank and make it's height adjustable

5. here is a picture of the built in refugium from the top

Two will be more than enough for that small of a fuge.

Perfect, I will use the other one for my display area build!

{ponders if Cheato might react to red LED light like terrestrial fruiting plants do - basically they go crazy over it}

Sorry - thinking / typing out-loud. Yet another experiment for my list :-)

That's what I'm hoping for! Also found a great way to suspend the heat sink! It is from a cheap lamp with a flexible metal tube. I pulled the wires out and now it is hollow so i can thread the wires from the led's down to the driver. My only question is will I lose any power with the length of wire? I believe I have heard something like 18''?

You will only have an issue if the wire is too small. Use something like 18AWG from the driver to the LEDs and you won't have a problem.

thanks for all your help on this! another question, what is the best way to apply heatshrink considering i dont have the money for a heat gun?

Hair dryer. Takes a little longer, but it should work. If it's not quite hot enough, cover the air intake partially. Don't do it for too long as it can shorten the life of the hair dryer.

thanks, i'm heading out to home depot today to get some supplies

weller 40 watt soldering iron
electrical tape
solder
polyoefin heat shrink
wirestrippers
wire

Here is my detailed list of supplies

Weller Soldering Iron 40watt
.040 silver bearing rosin core solder
18awg stranded wire
Benzomatic Micro Pencil Flame Torch (has attachment for heat blower and solder tip)
Project Box
Electrical Tape 33
16-26awg wirestrippers
Polyolefin Heat Shrink Tubing (1/8'', 3/16'', 1/4'')

1. Will using the 18 awg wire for the fixture make it more difficult to solder?
2. Is there a step by step guide to connecting the led's to the driver, and the driver to the power source, etc. I will most likely need some help with this because I do not have a very strong electrical background.

18awg isn't too bad. It's a little bulky going from LED to LED, but considering that you are only doing a few LEDs, it's manageable.

Connecting the driver to everything is easy. The driver has a positive and negative output to the LEDs, and a positive and negative input from the power supply. It will be obvious once you see it in person. The positive wire for the LED goes to the positive pad on the first LED, and the negative wire goes to the negative pad on the last LED.

Thanks evilc, you have been really helpful with this! Once my other supplies come in the mail I will start posting pics. If it all works out well I will make a thread with instructions.

how would i wire in the arduino microcontroller if i were to do that? would i plug the power source into the board then wire it to the buckpuck? i would need some help with the setup for this. here are the two parts i am looking at

Arduino Duemilanove USB Microcontroller Module
DFRobot LCD Keypad Shield for Arduino

You would need a power supply for the controller itself. Once you have that, you can follow some of the connection diagrams listed in the Buckpuck datasheet.

just got order from ledsupply







my question is how do I connect the power source to the buckpuck?
also does it matter that the buckpuck has 24awg wire and I will be using 18awg?

how exactly do i connect the power supply to the buckpuck? i am assuming i cut the wire on the power supply, but i need help with where to cut and identifying the - and +

Cutting the plug off is one option. The cable will either be two twisted wires that you will have to identify which is positive and ngative, or it will be a coaxial cable, where the center will be positive, and the outer will be ground.

The other alternative is that you go and buy a socket that will mate with the plug and wire up the Buckpuck to it. The plug on the power supply will normally be center positive, outer negative. The power supply will have a label on it to confirm this.

i made a mistake and cut way too short. is it possible for me to cut on this side

Sure. That lump is just an RF filter. It's the same cable on both sides.

Evil is correct. That just helps prevent interference.

thanks guys! i'm still waiting on a few parts to arrive then i should be starting the build in about a week! i'll make a thread on it when i'm finished and get everything worked out.

i've got a general question about power supplies

what size power supply would i need for these LED's?

4 royal blue Cree XR-E LED's wired to a 700mA buckpuck dimmable w. pot

4 * 3.3v = 13.2v + buckpuck power loss? = ?


3 cool white Q5 Cree XR-E LED's wired to a 1000mA buckpuck dimmable w. pot
3 * 3.3v = 9.9v + buckpuck power loss? = ?



Questions:
Which power supplies will work for each?
What do I need in a power supply in terms of amps, and watts?
If I get a power supply with more or less volts will it have an effect on the LED performance?

You would want at least 16v for the RBs and at least 13v for the whites. I'm using a 19v laptop power supply for my array that is very similar to yours and it works great, they are available on ebay for ~8 bucks each shipped. You'll probably have to change the DC plug on them since all the laptop supplies I've seen use weird plugs.

Just make sure you get one from a US seller, in this case the Hong Kong ones aren't any cheaper but you have to wait much longer.

okay, so i'm assuming the buckpuck uses about 2v?

Yes, it's stated right in the datasheet.

http://www.amazon.com/ADAPTER-NOTEBOOK-PA-...G/ref=de_a_smtd

will this power supply work, 19V 3.42A 65 Watt?

Yes, and actually that one comes with a common size DC plug on it so you don't even have to cut it off, just find a 2.5mm pin DC jack.

http://www.nuelectronics.com/estore/index....p;products_id=2

this is the only lcd shield i can find that plugs into the arduino micro controller

ordered the arduino duemilanove a few days ago and my parts are finally here for building my refugium light! i'm planning on starting the build today, and will post pictures later

started making the fuge light today, keep in mind this is my first led project and i learned a whole lot of things by making a good amount of mistakes

heat sink (looking back it could have been a little bigger)

soldering joints are terrible, this was my first soldering job

nice output, although from about 70% to 100% power there is no visible difference, and it does not fade as low as i had hoped, maybe a different driver will solve this?

the heatsink is fairly warm after prolonged use so I would like to put a fan on it, is it possible to wire in a 12v fan even though i only have a 12v power supply? or do i need a different one?

Shorten the exposed stripped wire that you are soldering to the stars. It's an accident waiting to happen. You don't need much more than 3/16" of exposed copper. An easy way to get it right is strip off more than you need, tin the wire all the way to the insulation, and cut to length.

12v fan + 12v power supply =

thanks for the tip! as far as the fan goes, the 12v power supply is the one that I am powering the 2 led's and buckpuck with. is it possible to include a fan on that power supply? 3.3v + 3.3v + 2v = 8.3v that would leave a little less than four for the fan. does that just mean it will run slowly or will it not even power up?

You would wire the fan in parallel with the buckpuck, meaning the fan attaches directly to the positive and negative of the 12v supply and both the fan and the buckpuck will get a full 12v.

The connection you might be thinking of would be a series connection and you don't want to do that in this case, most likely neither the fan nor the buckpuck would be able to get enough power to do anything if you tried it that way.

spend some time redoing the soldering and switched to a smaller wire gauge (from 18awg to 24 awg) and made a little improvement. thanks for the info about putting the fan in parallel. obviously there are a lot of flaws that hopefully will not be present when i build the main display light


added heat shrink

Much better.

haha thanks, i'm learning i got a the splash guards today, thanks to scooternerd, and a few tools from home depot

hows the build going? get those guards drilled yet?

not too bad, yeah i drilled the smallest guard for my light and i'm working on getting all the wiring and dimmer into a project box, i'll throw up some pictures when i'm done. these two led's output a lot of high intensity light for the chaeto! i'm also working on mounting a small fan to keep the temperature down because my heatsink is a little small.

I just switched from a 9w picotope CF lamp to a single 3w cree over my fuge like 10 days ago and the chaeto has exploded and it's the good thick/wiry/crunchy stuff now too. Your chaeto is going to be pretty hardcore with two of them.

Also just a hint, if you haven't already you might want to see how loud/fast that fan is at 12v before hard wiring everything in a case etc. Some of those small fans are surprisingly loud at full speed and you might want to wire in a resistor or something to slow it down a bit.

awesome, i'm hoping for some excellent growth from this! thanks for the tip about the fan, it actually is pretty quiet when it's about a quarter inch off the heat sink.

random question, how long would a 9v battery power a 12v fan, 5v fan or maybe a small 9v motor?

Not long enough to be cost effective. You can use most any DC wallwart from 5vDC-12vDC to power a fan and pay very little if you don't have one sitting around the house you can cannibalize.

+1, 9v batteries really are not made to put out any current at all. They run electronics pretty well but if you can see anything happening the battery is probably going to die real quick.

real quick as in a couple hours? or days?

A 9V battery is 0.55Ah and your fan probably draws 0.15A, so it will run for less than four hours.

alright thanks, just curious

lookin' good so far. I've been debating building a small LED fixture for the 10gal. refugium i will be adding soon, but like you i have very limited electronic experience. Looks to be fairly simple after reading this thread. keep us updated. Curious on how much better the chaeto grows from this compared to the PC bulb.