DIY LED Hood: Prebuild Thoughts...

mseepman · #1 01-19-2011, 11:36 PM

Well, it seems you've thought a lot about this already.

In regards to optics, just note that 40 degree optics really tend to spotlight the LED's so I would consider doing a bunch of 60's myself. If you go with fewer drivers..you need to do a little more detailed wiring to include fuses and resistors. When you do that, you will need to balance the strings, (move some LED's around) which is really tough if you use any method other than screwing the LED's to the heatsink. I tell you this because screwing them in means you need to tap the heatsinks (a bit of work).

As for controllers...I think the Apex lite can use their 1-10V add-on and it would be cheaper.

I'm a huge fan of LED and will be doing one of these myself with 180 LED's or so.

GMGQ · #2 01-26-2011, 08:27 PM

So instead of jumping into the big LED hood build, I figured I'd do a small scale project first.

I want to build a refugium LED light with 6 LEDs:

4 x Cree XP-G CW (3W, max drive = 1500mA, forward voltage = 3.0 @ 700mA)
2 x Cree XP-E RB (3W, max drive = 1000mA, forward voltage = 3.4 @ 700mA)

I plan on using a buck puck with a potentiometer. Will this one work?

http://www.ledsupply.com/03021-a-e-1000.php

If so, what power supply would I need for it to drive the 6 above LEDs? (24V, 1000mA as per the buck puck?).

And I assume I should wire them in series?

Thanks guys.

mseepman · #3 01-26-2011, 08:49 PM

Unless dimming these is of utmost importance to you (for a fuge I would think not) I would get either a meanwell LPC-35-700 or a LPC-60-1050 (if you want higer mA). This way you just wire it and go...if you need to add more LED's you can (up to 12). The buckpuck costs the same, but you still need to buy all the extras to make it run and it caps out at 6 LED's.
Just my humble opion though. Here's a link where you could get the Drivers. http://www.rapidled.com/servlet/the-Drivers/Categories

GMGQ · #4 01-26-2011, 08:54 PM

Well I want to dial back the voltage so that the LEDs arent running at 100%, plus this is a test project for me, so I want to see what varying voltages will do with the brightness/colour.

Also the buck puck is the size of a quarter, the meanwell is the size of a brick. I just figured I shove the buck puck into a little black project box from radio shack, and screw the pot into the lid.

What extras would I need with a buck puck? The one I linked to comes with the pot pre-wired, so I figure all I need is an AC power adapter?

LMK what you think thanks.

Quote:

Originally Posted by mseepman

Unless dimming these is of utmost importance to you (for a fuge I would think not) I would get either a meanwell LPC-35-700 or a LPC-60-1050 (if you want higer mA). This way you just wire it and go...if you need to add more LED's you can (up to 12). The buckpuck costs the same, but you still need to buy all the extras to make it run and it caps out at 6 LED's.
Just my humble opion though. Here's a link where you could get the Drivers. http://www.rapidled.com/servlet/the-Drivers/Categories

mseepman · #5 01-26-2011, 08:58 PM

Fair enough... One thought would be that I'm not sure that LED's are the best Fuge light. They've been known to significantly cut down on algae in tanks as they don't put off as much light in the spectrums that many algae's like. Not sure that will help grow your macro-algae either.

No extras on the BP, I just like simple and drivers are simple.

Lampshade · #6 01-26-2011, 09:38 PM

I"ve been doing a lot of research on this aswell, i've seen a few nice tanks with 40 degree optics, some even with 20. They tend to be layed out in a cookie sheet way, staggerings each line of LED's. I think it's more dependant on your density of LED's and the height mounted oabove the tank. 10" above the tank is pertty common, If you are going more than 2.5" centers on the LED's i would suggest 60 degree, if less than 2.5" then 40 should be fine IMO. Check out as many pics as you can to see what you're getting into.

and if you are using XP-E's a 1:1 ratio will be a 14K balance, if you use XP-G white's you can get away with less whites, forget the combo for 14K though. The blue's don't help growth much, basically for our viewing and popping coral color (The datasheet for cree shows this with the light off the whites, it's very close to the PAR we're looking for)

As for heatsinks, there's lots of choices, but generally people WAY over build heatsinks. Cree's give off a lot of heat, no doubt, but you can calculate the heat gain vs loss pretty easy to see what you actually need.(i posted links on some other recent DIY thread)

Drivers have lots of choices, meanwell's are popular as with the buckpucks. More drivers gives you more "zones" for dimming/control. 1 driver dims all the lights together.

As for cheap controllers. Depends on how fancy you want to get... but look at arduino boards. There's LOTS and i mean LOTS of LED builds using these. Uses C programming, but i've found many chucks of code online that people have posted that got their LED's working and controlable. Arduino's start at $20 for something that will control 2 drivers with PWM outputs and $35 for something that'll do 6(Arduino Mega). If you get into it the arduino can do pretty much everything, i'm building a tank controller based off one right now.

StirCrazy · #7 01-26-2011, 09:59 PM

Quote:

Originally Posted by Lampshade

As for heatsinks, there's lots of choices, but generally people WAY over build heatsinks. Cree's give off a lot of heat, no doubt, but you can calculate the heat gain vs loss pretty easy to see what you actually need.(i posted links on some other recent DIY thread).

I don't see a problem with this at all, I would rather have an overbuilt heat sink anyday than one that is a perfect match. so many people try to skimp on some things for a matter of 20 bucks, this isn't one area that should be done IMHO. for example.. if you fan dies on a exact sized heat sink and you don't know about it then you run the risk of burnning out several LEDs, if you have a over sized heat sink it reduces the chance of losing LEDs as you are not as dependent on the fan.

Quote:

Originally Posted by Lampshade

As for cheap controllers. Depends on how fancy you want to get... but look at arduino boards. There's LOTS and i mean LOTS of LED builds using these. Uses C programming, but i've found many chucks of code online that people have posted that got their LED's working and controlable. Arduino's start at $20 for something that will control 2 drivers with PWM outputs and $35 for something that'll do 6(Arduino Mega). If you get into it the arduino can do pretty much everything, i'm building a tank controller based off one right now.

on this topic, have you seen any dimming programs for Arduino using a varable voltage output instead of PWMs?

Steve

GMGQ · #8 01-26-2011, 09:44 PM

Hmm, well this is mainly for my chaeto down there :P Right now I'm using 2 CF bulbs, and they're growing like weeds. I just wanted to reduce the wiring/lighting clutter.

It's a small weekend project, so I'll try it out and see how it goes.

I still need to figure out the AC power requirements though...

Quote:

Originally Posted by mseepman

Fair enough... One thought would be that I'm not sure that LED's are the best Fuge light. They've been known to significantly cut down on algae in tanks as they don't put off as much light in the spectrums that many algae's like. Not sure that will help grow your macro-algae either.

No extras on the BP, I just like simple and drivers are simple.

Lampshade · #9 01-26-2011, 09:53 PM

I think the cheato should do fine, the cree white's are a 6500 - 10K bulb, that's what i use on mine and they grow great. I think the reason people have problems is the intensity of the light, most algee gets nuked in VERY bright lights, and LED's have the same intensity(lumens) per watt as some of the best MH bulb available. Just keep them up a bit and don't use optics and they'll do fine.

GMGQ · #10 05-24-2011, 05:40 PM

The LEDs game last friday, so I spent the evening gluing them onto the fixture and wiring everything up!

DIY Aluminum Fixture:

I used 2 of the left piece side by side for the main body, and I interlocked and riveted in all 4 sides with the right piece.

Top View:

Bottom View:

Side View:

LEDs:

I was going to install a piece of plastic on the bottom as a splash guard, but I havent gotten around to getting the plastic. But now I'm wondering if it's even necessary. I'll probably hold out.

Grommets for running wires through:

Wired up (48" strip of blue LEDs as Moonlights wrapped around fixture):

Temp electrical station :P

Top view with fans (80mm Aluminum fans with blue LEDs, fitting):

Front View:

Fixture runs COOL TO THE TOUCH on full load. Blues at 800mA, Cool Whites at somewhere over 1000mA. One of my goals was to demystify the belief that you need those honking 20lbs+ Amplifier style heatsinks. Pretty cool that ALL the parts of the fixture are aluminum, from the body to the rivets, and even the 2 fans and the screws are Aluminum. I'm very happy with this LIGHT WEIGHT fixture.

I had made the 8LED Fixture, and now this. It's been really good practice. This second one took me no time at all. It's all about the planning. However, I did not anticipate building this 28LED fixture, so the big fixture for my display tank has been pushed back to next year. I just got a new order of bulbs, so they should hold me over until the next LED build (I'm thinking around 60 LEDs next year).