Designing an LED build

[doctaq]

what happens is that the meanwell supplies power to the leds in the constant current mode that leds need, the reference voltage tells the meanwell how much power to put out, the reference voltage can be created by a 12v adapter (which can also be used to power fans) and a lm317 circuit which will allow you to drop that voltage lower or higher depending on how bright you want your leds. 10v matches up to the max setting of the meanwell

 

the adapter you linked to is plenty powerful, you could run up to 10 fans on that if you wanted for some reason

[Mr. Microscope]

Okay. So, I've taken what I've learned in the last 16 hours and reworked the design. I think I'm getting closer. The new design contains a few more LEDs and some different drivers. What do you think?

 

 

LED side

Fan Side



Key and Plot

 

 

 

Note: The heatsink is a little small at 5 3/8" square. I'm planning to spread things out a little to maybe 8 inches square.

 

Sorry, I realize the text is hard to see.

Here's some clickable thumbnails that should be larger:

[marinoob]

2 things .....

 

1st you dont need a 24v power supply for the buckpuck with 1 3w led on it. im not sure what the cyans forward voltage is but im sur eits not 22v. you need 2v for the buckpuck and usually around 3-4v per led. 24v would be overkill. i tihnk a 12v would be fine to run 1 buckpuck with 1 led and 2 12v fans.

 

2nd i think you can use 1 universal powersupply to power the dimming of the meanwells. you show 2 individual powersupplies

 

i would do 1 universal powersupply for both meanwells and 1 universal powersupply for the buckpuck and 2 12v fans......

 

that sounds better to me but i always try to do things as cheap as i can without risking too much quality.

[Mr. Microscope]

2 things .....

 

1st you dont need a 24v power supply for the buckpuck with 1 3w led on it. im not sure what the cyans forward voltage is but im sur eits not 22v. you need 2v for the buckpuck and usually around 3-4v per led. 24v would be overkill. i tihnk a 12v would be fine to run 1 buckpuck with 1 led and 2 12v fans.

 

2nd i think you can use 1 universal powersupply to power the dimming of the meanwells. you show 2 individual powersupplies

 

i would do 1 universal powersupply for both meanwells and 1 universal powersupply for the buckpuck and 2 12v fans......

 

that sounds better to me but i always try to do things as cheap as i can without risking too much quality.

 

I thought the 24V was overkill for the cyan, but I thought I needed it for the two fans. Thanks.

 

For the MeanWells, I thought they had their own power supply. The things they are connected to are these

http://www.nanotuners.com/product_info.php...products_id=119

recommended on nanotuners for dimming. I want to have the blues and whites on separate outlets for different timing (sunrise/set, etc.).

 

You rock marinoob! Thanks for putting up with me.

[doctaq]

your post is as confusing as ever haha.

 

read through my post, i think i broke it down pretty easy there

[Mr. Microscope]

your post is as confusing as ever haha.

 

read through my post, i think i broke it down pretty easy there

 

D'oh! Thanks. I'll check out your build. Do you have a link to it? I didn't see it in the Comprehensive DIY LED Project List.

[doctaq]

nah not my build, i only have a couple of projects that are fully dimmable and they all use buckpucks, personally im more interested in the transistor based driver

[Mr. Microscope]

read through my post, i think i broke it down pretty easy there

 

Which post then?

[doctaq]

"

what happens is that the meanwell supplies power to the leds in the constant current mode that leds need, the reference voltage tells the meanwell how much power to put out, the reference voltage can be created by a 12v adapter (which can also be used to power fans) and a lm317 circuit which will allow you to drop that voltage lower or higher depending on how bright you want your leds. 10v matches up to the max setting of the meanwell

 

the adapter you linked to is plenty powerful, you could run up to 10 fans on that if you wanted for some reason

"

 

few components here, the meanwell is key, and the 12v adapter is also key

 

the meanwell will have 3 pairs of wires, one pair goes to the leds, one pair goes to the wall and the last pair is for dimming. the 12v adapter will attach to two things, a fan and a lm317 circuit, the lm317 circuit then connects to the meanwell dim wires

 

if you are looking for a single led on its own driver there is a driver on dealextreme that accepts ac input and drives a single led to 700ma

[Mr. Microscope]

Cool. Thanks for breaking it down there! Very clear.

Do I hook up a separate pot to the LM317 or is all the dimming handled on the adapter?

How does the fan hook up to the adapter (is there more than one input on the adapter?)?

[nick33063]

Nope, one buck per string. Even easier would be to use two dimmable meanwell drivers, one per string. They have a power supply built in.

 

Matt

 

Matt, I plan to purchase 2 Meanwell ELN 60-48D drivers to run 20 LEDs, 10 White, 10 Royal Bluue. I'm intrested in my statement about the Meanwells having power supply built in. I've have few people including the supplier of the Meanwells and LED's I plan to purchase tell me I need to buy a 9V wall wart to power the Meanwells.

 

From my reading of the specifications of the Meanwells we should be able to directly connect to the wall outlet and they will output the correct voltage.

 

Meanwell Specs:

 

INPUT AC CURRENT (Typ.) 1.2A/115VAC

INPUT VOLTAGE RANGE: 90 ~ 264VAC/ 127 ~ 370VDC

 

OUTPUT DC 48V

OUTPUT LED 24V ~ 48V LED

[JBM]

forgive me if i didnt read it, but what size tank is this going over?

[Mr. Microscope]

This is for a 25 gallon Mr. Aqua 18 inch cube. Too many LEDs?

[markandstaci]

I like the design, but are you worried about the cyan spotlighting? The reason I mention this is because you said you are doing a pillar design for this tank, so depending on where your pillar is and how high your light is mounted, you might spotlight the top of the pillar with cyan.

[Mr. Microscope]

I like the design, but are you worried about the cyan spotlighting? The reason I mention this is because you said you are doing a pillar design for this tank, so depending on where your pillar is and how high your light is mounted, you might spotlight the top of the pillar with cyan.

 

Good point. I was planning to drive it very low with a 350mA buckpuck. That is certainly worth some additional thought though. Thanks!

[Genj]

Great and interesting posting from all, with information that makes my head spin. I'm curious as to what lenses you are going to use as well, and when you do get it all worked out, don't forget to post what you did along with your very nice layout images!

[Mr. Microscope]

Great and interesting posting from all, with information that makes my head spin. I'm curious as to what lenses you are going to use as well, and when you do get it all worked out, don't forget to post what you did along with your very nice layout images!

 

Thanks! I worked on design03 this weekend. I'm actually bouncing back and forth between using buckpucks and figuring out the meanwell thing. So, 03 might be two different designs to weigh pros and cons. I will certainly post the final design before building it. I'm not planning to use any optics for this light. That may change in the future though.

[Genj]

What's the determining factor for you to not use optics? I've noticed some people are using them and some not, but for reasons not stated. Tank depth, color variety, color shadowing, etc?

[Mr. Microscope]

What's the determining factor for you to not use optics? I've noticed some people are using them and some not, but for reasons not stated. Tank depth, color variety, color shadowing, etc?

 

I'd like to see how well it works without optics. My lamp now has 80 degree optics and I think it's too intense (based on coral reaction), however, the depth of my new tank will be at least twice my current one. So, I may change these plans in the future. That is a good question though. If anyone wants to chime in with some advantages VS. disadvantage please chime in.

[Genj]

Making any progress on your build?

 

BTW, do you now what the dimensions are of the LED, including the star?

[Mr. Microscope]

Thanks for checking in GenJ! I'm actually on like design number 8 right now. I haven't bothered to publish any because I keep revising the design, but I think I about have it right now. I might post it tomorrow if I finish it. Stay tuned!

 

As for the dimensions on the LEDs, I'm not sure about the exact size, but it's pretty small. I think they are slightly larger than a penny. You can download a pdf datasheet on ledsupply.com. It should have the dimensions along with everything else you might want to know like vf and lum vs. mA drive.

[Genj]

I'm on #5 myself. I've worked out most of the design, now it's just a matter of some PMs between evil and I to get it worked out.

 

I answered my own question as well. They are 20mm diameter on the star.

 

Have you figured out your dimming yet? doctaq sent me a link to the lm317 schematic which I'll have to figure out. I'll share what I find..

[Mr. Microscope]

Hello All,

 

It's been a while since my last design post. Well, I've been revising the design too fast to post any of the intermediates, but have finally pinned it down to a layout I like.

 

I also updated the size of the heat sink to be accurate to the one I will order. If I read their site correctly, heatsinkusa.com has several different widths that they can cut to any length (at lease I hope I read that right because I'm basing my design on that lol). My future tank will be an 18 inch cube. So, I decided the 7.28 (about 7 1/4") inch heat sink would be sufficient. I will request that they cut it square.

 

I'm planning to get some nice white acrylic and build something similar to M@rine_lover's light. However, shaped more like Aegeon's light. Also, for the potentiometer knobs, I was thinking about trying to rig these up (the gold ones). They don't have the right sized hole on the inside, but perhaps I could epoxy it somehow. They also have a hex screw to tighten, but I don't want to relay on that.

 

I've also decided to cut back on the number of LEDs (with room to expand in the future). I was adding stuff up cost wise and decided that although this light could last a very long time, I'm not ready to invest upwards of $400 on it. Also, with the recent discussion about LED color, I've decided to go with more than two colors. I'd like the ability to tune them all more or less individually. So, I've decided to go the BuckPuck route. All this after I read through the 42 page MeanWell thread and figured out the LM317/PWM/ELN-60-48D Vs. P madness.

 

You'll also notice that I configured the LED array in a rather unique fashion. This is what's been taking me so long (that, and all the reading). I figure the biggest drawback to LEDs is their potential to, "spotlight" or cast color shadows (both of which I'd like to avoid because I'm planning a pillar style rock scape with an overhang). They are, after all a bunch of extremely intense points of light. Until three-ups are affordably available (e.g. NW, RB, and CB on the same wafer) like DaveFason is working on, we need to be creative with our arrays. Properly blending colors is one of my goals with this build. I decided to base my layout on sets of six since the BuckPucks can only power six. Going back to my days of drawing fractals and odd geometry (yes, I used to stare at Black Light posters and blast DJ Spooky too ), I decided to fall back on good old Phi. The golden ratio. This is a formula that is found all over nature and can be seen in the shells of our favorite clean-up crew members.

 

So, before I finish writing a book, here's the design. It's actually design number 11.

I decided to use the clickable thumbnail instead of putting it in the post because the text in Sketchup is too small to read on a shrunken image.

 

Here's the array schematic so that I can reproduce it on the heat sink:

 

I based the above design on this layout. It's composed of 9xRB, 3xCB, and 6xNW.

 

I was also very excited to see Evil's post about the upcoming True Violet LEDs. So, here is Option 2. 6xRB, 3xCB, 3xTV, and 6x NW. I'm not sure how I would drive this. I might end up with 4 drivers for this design (500mA for the TVs).

 

Option 3 brings back in the CWs. I'm hesitant to get rid of them entirely. So, I'm thinking about this one too. I do see how they can wash out colors though, which is why I only put three in here. I’m afraid they may overpower the NWs in a 50:50 ratio though. 9xRB, 3xCW, 3xNW, 3xCB

 

Finally, Option 4 has the Cyans. I desided to ditch the cyans back in design number 4; thinking that the CB's might provide enough cyan by themselves, but thought I'd throw this design out there for conversation anyways. 6xRB, 3xCB, 6xNW, 3xCyan. I'd probably have to run a fourth driver with this setup too.

 

 

Discussion:

 

1) What do you think of the design? Too many, too few LEDs for tank? Too tight, too spread out? Anything else? This is my first build. Constructive criticism is welcomed!

 

2) Do you have an opinion on the colors options? Which layout do you like best and why? Do you have a different suggestion for number, ratio, or color choice?

 

3) What is the real benefit of cool white? I know it’s 6500K which is good for plant based photosynthesis. Would my corals really suffer without it?

 

4) Also, I'm starting to think more and more about optics. The fixture will likely be mounted pretty close to the tank, but the tank will be 18 inches deep. Also, having the ability to dim the LEDs lessens the risk of photo-bleaching. Though, I may be risking more spotlighting and color shadows with optics. Any thoughts?

 

5) There are two pieces of equipment I haven't picked out yet:

-First, the fans. I'll be wiring in 2x12 volt fans in series into the Potrans with the RBs. I'm not sure about brands. Suggestions appreciated!

-Second, the moon lighting. I'm planning to wire in a moonlight (probably a white one, cause, hey! the moon is white, but I’m not stuck on it..maybe blue. I’ve never been diving at night, anyone? Bueller?). This will probably be something with it's own wall wart that I can plug into it's own timer. Again, suggestions appreciated!

 

6) Finally, I have a couple questions about potentiometers. First, can they be swapped out on BuckPucks (I supposed, I could just get the wired Bucks without pots)? Second, what's the difference between say, a 5K ohm pot and a 100K ohm pot. I was googling this, but couldn't find the answer believe it or not. I even looked at the wiki page. I know ohms have to do with resistance and that a potentiometer is essentially a variable resister. From what I gather, I think they are interchangeable, just that the 100K ohm pot is maybe more sensitive to dialing and maybe makes more physical rotations than the 5K? I could be way off, but that's my best guess at the moment.

 

 

Thanks in advance to your advice, criticism, answers, looking at my thread, and having the patience to read this monstrosity of a thread post!

[Genj]

OK, I've got a post to read tomorrow after I wake up!

[Mr. Microscope]

OK, I've got a post to read tomorrow after I wake up!

 

Any thoughts?