DIY LED Using 10 Watt Arrays

[eli@fijireefrock.com]

I skimmed through this tread a little fast excuse me if this question already have an answer
As I am planning to do a 20W led setup for a couple of my tanks similar to what you are doing but 1st I would like to know how good are these fans at keeping these LED cool as I am planing on running then at full power.
By the way good thread on this build.

[chewie]

Very informative read. I am in the process of trying to figure out how to do a build myself, following along this thread to see how it is done.

Here is a list of parts I am thinking of using:

Dimmer. ( may have a few to run different led temps, blue, daylight 12000k etc...)
http://www.dealextreme.com/p/dimming...s-dc-12v-73618

Daylight 12000k
http://www.dealextreme.com/p/t10-sv8...-dc-12v-112583

Blue light
http://www.dealextreme.com/p/10w-180...r-9-11v-100875
OR
http://www.dealextreme.com/p/31-44mm...-dc-12v-100622

Power supply ( once again a few to run different lights on timer. Not sure if this will work or if I need an actually LED driver supply. )
http://www.dealextreme.com/p/120w-un...-240v-ac-37110

or if I need a proper led driver
http://s.dealextreme.com/search/led%20driver%2012v

any suggestions?

[mike31154]

Originally Posted by chewie

Very informative read. I am in the process of trying to figure out how to do a build myself, following along this thread to see how it is done.

Here is a list of parts I am thinking of using:

Dimmer. ( may have a few to run different led temps, blue, daylight 12000k etc...)
http://www.dealextreme.com/p/dimming...s-dc-12v-73618

Daylight 12000k
http://www.dealextreme.com/p/t10-sv8...-dc-12v-112583

Blue light
http://www.dealextreme.com/p/10w-180...r-9-11v-100875
OR
http://www.dealextreme.com/p/31-44mm...-dc-12v-100622

Power supply ( once again a few to run different lights on timer. Not sure if this will work or if I need an actually LED driver supply. )
http://www.dealextreme.com/p/120w-un...-240v-ac-37110

or if I need a proper led driver
http://s.dealextreme.com/search/led%20driver%2012v

any suggestions?

The dimmer is something I've also been looking at to control the current my 12 Volt power supply delivers to the LEDs.

The daylight 12000K 5630 SMD LEDs are generally considered insufficient for our purposes, since the LEDs are not large enough to penetrate the water properly. Yes, there are 32 of them on the board for 16 watts, but I'd still advise against trying to use these since they just don't have enough punch per individual LED. About the only advantage to them is that since they're designed to replace automobile lighting, any 12 Volt DC power supply may be used to run them, no driver to worry about.

Your first link for the blue light is the same 10 watt LED form factor that I'm using in different colour temperatures. You will need either large heatsinks, or the fan/heatsink combination I'm using for my build. You will also need either individual drivers for each 10 watt LED, or a power supply in the 12 Volt DC range of sufficient rating to run multiple 10 watters in addition to a current limiting resistor for each 10 watt LED.
The second link for blue light is again, a board with low wattage 5050 SMD LEDs really unsuitable for anything except maybe a night light.

With respect to power supplies/drivers, the preceding paragraph should pretty much answer that. Your choice really. You can either get a separate driver for each 10 watt LED, or a larger 12 Volt DC power supply to drive a bunch of them with current limiting resistors for each 10 watt LED. If you decide to use the SMD LEDs for sunrise/sunset or night lighting, all you need is the 12 Volt DC power supply on a timer.

[chewie]

I would love to do a build like yours or Grizzs using leds from Modular Led but just cannot justify the cost a.t.m . I am trying to go cheap and thought going 12v would simplify things. My tank is only 18" deep so was hoping to get away with it...well maybe I should stop being cheap and use proven led's from Modular.

[mike31154]

Originally Posted by chewie

I would love to do a build like yours or Grizzs using leds from Modular Led but just cannot justify the cost a.t.m . I am trying to go cheap and thought going 12v would simplify things. My tank is only 18" deep so was hoping to get away with it...well maybe I should stop being cheap and use proven led's from Modular.

If you wish to pursue the 12 V simple approach, you might want to look into the MR16 bulb form factor. They are designed to run off 12 VDC, even 12 VAC in some cases. Driver built into LED bulb, plug & play, sort of. Price is coming down on these bulbs & I understand there's a company about to launch more efficient/powerful MR16 LED bulbs. Initial customer base will be commercial, but shouldn't be long until they target the domestic consumer.

It's slowly getting to the point where it's more difficult to realize significant savings in a DIY LED build as long as you're not looking for all the bells & whistles such as an EcoTech Radion.

Below are some MR16 bulb pics. This bulb has four 1 watt LEDs in it & pretty good optics. You can even unscrew the bezel & remove the optics if you wish. This would expose the individual LEDs & provide more spread, but also expose them to water spray. They are very bright. Before embarking on the 10 watt LED chip build, I was seriously considering this option. I may still use some of them as supplemental lighting or to spotlight a particular coral/area of the tank. Of course if you have primarily low light corals etc. in your tank, those car lights might be enough, but I wouldn't count on it. For a FOWLR they'd probably be ok.

[mike31154]

Been a while, lots of skiing so not much work on the LED project, but I did manage to get a little more done. I've decided to go with a third rail down the center. Probably have some funky coloured night lights & one or two day supplement arrays on that. Maybe even a green or red. The two outer rails will do the bulk of the work. I've cobbled them together using two pieces of plywood to experiment with spacing & get an idea of what kind of spread the currently planned mix of LEDs will give.

I've ordered 10 more heatsinks with fans & 10 Blue arrays to see how they will work with the current bunch of Royal Blues & 10,000K. Still need a bunch of 5 to 10 watt resistors in the 1.5 to 3.3 ohm range to tune each LED array to the proper running voltage/current. As it sits right now with 17 LEDs, heatsinks, aluminum & plywood, the unit weighs in at 1.8 Kg, that's 4 lbs. Nice & light. Current plan will be to have 9 LED arrays on the two outer rails & maybe 4 to 6 on the center rail. Also need to add the weight of resistors, more wire, project boxes to wire the whole shebang etc. Might also add some plywood skirting to make some sort of open hood in order to minimize light spill & hide the aluminum. With any luck I'll be able to keep it under 10 lbs.

Here it is. Spacing between LEDs on each rail will be approx 4.5 inches. Spacing of LEDs between rails is around 5 inches. I plan to rotate the outer rails slightly inwards. No optics, I'll play with height above water to find a good compromise between spread & light output.



End view. The plywood will allow me to drill holes easily & reposition the rails if necessary. The wingnuts provide quick adjustment of the inward tilt of the outer rails.



Another view to better illustrate the tilt on the outer rails.

[mseepman]

Any new developments on this Mike?

[mike31154]

Originally Posted by Elias@caco3reef.com

I skimmed through this tread a little fast excuse me if this question already have an answer
As I am planning to do a 20W led setup for a couple of my tanks similar to what you are doing but 1st I would like to know how good are these fans at keeping these LED cool as I am planing on running then at full power.
By the way good thread on this build.

Sorry for the delay in answering your question, I've just returned from a week long backcountry ski trip!

The fans in combination with the heatsink do a great job of cooling the 10 watt arrays since they are more or less designed for them. There are alternative options without fans in the form of larger heatsinks, but I'd like to keep the aluminum mass to a minimum. If you do any searching on eBay for similar items, you will find plenty of sellers offering heatsinks with fans suited for the larger 20 watt LED arrays, as well as the big honking 50, 100 & even larger ones. Needless to say, as you go higher with the wattage, the corresponding heatsink & fan will also have to be much larger to cool the LEDs.

The fans on the heatsink for my 10 watt arrays are designed to run at full speed with 12 Volts DC. I decided to wire the fan leads to the LEDs so that my fans will run at a lower speed, since the LEDs will be run at anywhere from 9 to 10 Volts DC, depending on the size of resistor I put in series with each LED array. I've done some initial short runs to test the rail & it looks like this approach will be fine. If I need more cooling, I may simply add another piece of angle aluminum facing up to give the assembly additional mass for drawing away heat.