DIY LEDs - The write-up

[EBOLII]

Images of your power supply hook-up.

In my mind why would you not be able to wire in series say 3 power sources from [110v standard wall plug]. How many buckpucks [LED drivers] can run off each power supply [from what I am understanding depends on the LED source vs desired output, either 1w or 3w etc]
so then to sum it up...3 power sources that run 700ma and 3 power sources that run 1000ma hooked into one 110v line. or am I way off in understanding? [for a 72"L light setup]

[Soundwave]

Oh that. I need to pull the fixture out of the canopy to do that and I really want to wait until I have some time to not disturb everything in the tank. I'll see what I can do, though.

As far as how many pucks can run off a single power supply, I would recommend that the power supply be able to supply as many amps as the drivers are rated at. What I mean by that is if you have say 4 1000mA buckpucks, you need at least a 4 amp power supply. If you are running a full 6 LEDs on each buckpuck, ensure that you are using at least 24 volts. If you are running only 3, you can use a 12 volt power supply. One LED, 4 volts.

If you can get lucky enough to find a power supply that delivers 12V at 700mA, you can do without the puck and run 3 LEDs on it. However, I don't know if the supplies are regulated to keep the current absolutely constant.

On one of my projects, I used a cordless phone adapter that runs 12V at 350mA. It worked just fine running three 1 watt Luxeons. Like I said, though, I don't know if that's kosher.

[chimmike]

So is there an evolution based on various posts in this thread that it can be said now to use such and such buck puck over another, etc?

I'm contemplating putting together a fixture for a tank i might purchase in the future, and if t5's are going to cost as much, I'd rather do LED's.

[ME2003]

Doing a similar project, I used laptop power supplies. Each light
will have a separate power supply of ~65 watts. They can be bought
for ~12 each on ebay. The concept is to create two pendants to go over my 75. I agree the lenses on the solaris reduces the light output.
I also use 10 watt LEDs for a greater shimmer effect. Do you get this
effect with your setup?




More details here
http://www.clubswam.org/forum/index.php?topic=3297.0

[Soundwave]

It shimmers like halides never could.

[Soundwave]

What kind of LEDs did you use for the giant ones on the heatsinks? Also, do you have par readings on that?

[bebereef]

By the way ME2003, i would like to have a better description of all the parts you used for that project.
Thank's

[ME2003]

Here is some further information let me know if you
have any other questions. The 10 watt LED are
cool white (>5000k) and the 3 watts vary between
cool white and blue. It is still a work in progress.
For my 75, I will probably build two and also use two t5 bulbs. I may also add one more 10 watt led to each light.


The 3 watt leds are driven by the buckpucks and
the circuit is described in the buckpuck datasheet.
The 10 watt is driven by a circuit that is very
inefficient and produces to much heat.
I will be replacing it with another circuit.
It may be based on this article.
http://www.instructables.com/id/1.5A...for-LEDs-for-/



The 10 watt cool white LED with heat sink I purchased here.

http://stores.shop.ebay.com/Sure-Electronics_Components
They are also available here.
http://stores.ebay.com/led-world2007


The drivers for the 3 watt LEDs
http://www.ledsupply.com/03021-d-i-700.php
http://www.leddynamics.com/LuxDrive/...1-BuckPuck.pdf
http://www.ledsupply.com/buckpuck.php

The power supply is a laptop 18.5 volt 65 watt from here. $12.79
http://stores.ebay.com/econnect4u

[ME2003]

Also, do you have par readings on that?
I don't have a par meter. I may be able to get one
in the next couple of weeks.

[bebereef]

Big thumbs up for quick respond!
I'm into planning my next system witch will be a 6 or 8 footer and LEDs may be my next route as a DIY project.

[ME2003]

"24 Cree White LEDs mounted on star boards"

I bought every type of LED in this format i could find and Cree was the best choice.
If you look at the picture, it has several different vendors LEDs
The Luxeon did not seem as bright and was almost impossible to solder.

[Canoe]

For those of you considering alternate power sources, if it self-regulates or you add a regulator to it to get the voltage that matches your string of LEDs, then great.

If not, if you need to curb your power supply, remember that you can put a small current sensing resistor in the middle of the string of LEDs (another adaptable beauty of Soundwave's design!), instead of on the top or bottom. This means an inexpensive op-amp can be used for reading the sense resistor instead of the hugely expensive rail-to-rail op-amps required for high-side or low-side current sensing. With an appropriate reference voltage, the op-amp can drive the gate of a VFET on the low-side of the LED string to limit the current. The closer the power supply is to the required voltage, the less is wasted in the VFET (but it needs enough voltage to go across all the LEDs, the sense resister and the VFET).

Then, instead of a fixed reference voltage, by controlling the reference voltage to the op-amp, you get dimming function. With a driver circuit for the reference voltage that cycles it, you can get what every on/off pulse cycle you desire, reduce energy use, extend life of LEDs, sync to your stereo bass beat...
No. Bad Canoe. Baaad Canoe.

[bebereef]

So Cree is the way to go!
As for laptop power supply, you really recommend them?

[ME2003]

As for laptop power supply, you really recommend them?

With my design and other DIY designs, I don't have enough
lifetime data to recommend them. It is a power supply used
to provide 65 watts at 18.5 volts for laptops so it does have
a past history of success in a different application. I know this
is somewhat of a disclaimer but without more data I would not
recommend or not recommend either power supply.

At this point, I am looking for feedback on this solution compared to others.

[bebereef]

Ok then i will put that on hold for now and reed more...
Thank's anyway!

[Soundwave]

The laptop power supplies do work but you're right, their intended purpose is not what they are being used for. Using a true power supply like the ones I linked to at mpja.com are far more reliable and are meant to supply power for long periods.

[marspeed]

http://www.reefsanctuary.com/forums/...ng-system.html


found this today

[ME2003]

"The laptop power supplies do work but you're right, their intended purpose is not what they are being used for."
I think a laptop will be okay long term.
I think it is an acceptable use. I just don't have the data to confirm. The price your vendor list is very good so this decision is mostly preference. I don't like the open case on the supply you purchase, do you enclose it for protection from salt water?
The are also systems that provide high current at a low voltage that may be more reliable parallel source. Has anyone looked at these? These DIY led system get better all the time. Your design
is the best I seen so far.

http://www.dealextreme.com/details.dx/sku.11809

http://www.dealextreme.com/products....search.current

[Soundwave]

I keep the power supplies in a box that I made with fans keeping them cool. The box is under an end table that sits next to the tank. I do need to add a cowl or something to the assembly as I have cats, as well. I can only imagine the sound I would hear if one of them put their curious paw in the fan while its spinning. I have a lot of plexi sitting around so I'll probably improvise something with that.

Thank you for the design comment, by the way.

[Keith Elliott]

I am in the process of setting up my 280, and was considering going with a led set up similar to Soundwaves. My tank is 72x30x30 so I was going to make three setups for each opening in my euro brace. Just like Soundwaves, but I would use two 3x6 led rows on each heat sink for a total of 36 per opening. My question is will that be enough light or should I use two 4x6 led rows per opening? The tank will be 80%LPS 20% SPS. Also if you use the buckpucks with the dimmer can you connect the pots together to dim multiple units at once?

[KKamy]

Originally posted by Keith Elliott
I am in the process of setting up my 280, and was considering going with a led set up similar to Soundwaves. My tank is 72x30x30 so I was going to make three setups for each opening in my euro brace. Just like Soundwaves, but I would use two 3x6 led rows on each heat sink for a total of 36 per opening. My question is will that be enough light or should I use two 4x6 led rows per opening? The tank will be 80%LPS 20% SPS. Also if you use the buckpucks with the dimmer can you connect the pots together to dim multiple units at once?

Hey Keith,

I am going to be setting up a tank of similar dimensions 72x24x31. I have posed this question to Evilc66 over on nano-reef dot com. He seems to think that will not provide enough light if you are going to want clams down on the sand bed. You will need to decrease spacing between LEDs and use optics to increase PAR values lower in the tank (would be like a 400w MH equivelent).

He is going to run the numbers of how many LEDs to reach that for me, but has not gotten to it yet. Why don't you pose the same question over there and maybe he will finally run those numbers

[Soundwave]

You have an odd case, Keith. With such a deep tank, you might need optics to get the PAR needed for the amount of SPS you want to keep. That being said, you will probably need to use at least the 4x6 idea. I got some optics from a friend and they cut the pattern way down. Much brighter, though.

[KKamy]

Originally posted by Soundwave
You have an odd case, Keith. With such a deep tank, you might need optics to get the PAR needed for the amount of SPS you want to keep. That being said, you will probably need to use at least the 4x6 idea. I got some optics from a friend and they cut the pattern way down. Much brighter, though.

Lol, typing at the same time

[bolis03]

Deal Extreme carries E27 Base Cree 10w lamps, could you wire 4 this together along with some 3w blue leds to make a small pendant? I have a 48 L x 24 w x 18 H tank so I'm thinking 2 or 3 pendants?

[lynxvs]

Originally posted by ME2003
"24 Cree White LEDs mounted on star boards"

I bought every type of LED in this format i could find and Cree was the best choice.
If you look at the picture, it has several different vendors LEDs
The Luxeon did not seem as bright and was almost impossible to solder.

That's not true the lumen output is the same if not better...... They are small and hard to solder though. And they are cheaper...