Mr. Microscope's LED Build

[Mr. Microscope]

Mr. Microscope's LED Build

 

 

INTRODUCTION

 

I’ve just finished building some LED's for my 3 gallon picotope.

 

I've always considered presentation to be a very important part of any creation. For example, one can put up just about any piece of fine art on the wall and it could be made by Van Gough or any other famous artist, but you might not know if it weren't well framed, well lit, and hanging in an impressive gallery space. Basically, I'm tired of seeing LED's slapped on a heat sink that's screwed onto a piece of rough wood with wires strewn about everywhere.

 

I also grew up watching MacGyver and believe in making cleaver use of the materials that you have within arms length. However, I have absolutely no experience building anything electrical of any kind, and have very little experience using tools. I've never been a very handy person. As a teen, I'd be up in my room drawing in my sketchpad and listening to music while I could have been learning from my engineer step-father who was downstairs working in his shop. D'oh! I never had an interest in doing anything DIY. That all changed recently when I wanted some LED's for my tank, but wasn't willing to shell out $700 from company for something that didn't work exactly the way I wanted.

 

Another challenge I have is a severe lack of physical working space. I live in NYC in a studio apartment with my wife and a cat. As you can imagine, there is no room for a work bench or any large power tools other than what can be stowed under the bed.

 

 

HISTORY

 

When I started my tank, I was running a 18 Watt Current Satellite PC fixture over my picotope. This light was sufficient to keep softies and I even had a small birdsnest SPS growing under it for a few months, but at 10,000K everything in the tank lost all color and turned depressingly brown. I knew I needed something with a lot more power. I knew with a pico reef, heat is a major issue and I was very hesitant to go with metal hailide over such a small tank. LEDs were becoming all the rage and after seeing some in person, I knew they were the perfect solution. After about six months I replaced the PC’s.

 

 

I upgraded to a PAR38. It has two cool whites and three royal blue 3 watt Cree XR-Es. Additionally, 80 degree optics are mounted over the emitters for a little added punch. This light served me well for about ten months. Though it wasn’t the perfect solution.

 

This lamp is incredibly powerful and needs to be mounted very high above the tank. When I first installed it, I accidentally bleached a bunch of stuff. It took me several months to realize just how high this lamp needed to be mounted over my three gallons. Also, being wired into a bulb makes it impossible to dim. Finally, the color was a huge improvement over my 10K PC’s, but over time I found the light to be a little too icy. After some research I realized that the problem lay in the Cool Whites. Their color temp is about 6500K. The blue in these LED’s overlap with the blue in the Royal Blue LED’s. All of the warm colors such as reds, oranges, and purples were incredibly washed out.

 

This is what lead me to D. I. Y !

 

 

GOALS

 

My goals were to build an attractive light with clean lines. All LEDs are to be dimmable and on their own power supplies so that I can rig them with timers for a sunrise/sunset effect.

 

I used mostly my Swiss Army Knife and a few simple hand-tools that came in my toolbox. The only exception to this is an 18V drill that I have and a soldering iron which I purchased for the project. The majority of parts used were salvaged from whatever nooks and crannies I could find.

 

 

PARTS AND COST

• PC heat sink with mounted 60mm fan: Salvaged
  
• Acrylic for housing: White: Salvaged from an old light box, Clear: $20
  
• Screws and bolts: Salvaged
  
• Soldering Iron: Sinometer 60 Watts Soldering Iron. $10
  
• Solder: American Terminal AT-31604 60-40 Rosin Core Solder (4 Ounces) $12
  
• 22 Gauge Wire: Salvaged
  
• LED's (All Cree XR-E) : 2x Neutral White, 4x Royal Blue, 1x Cool Blue = about $50
  
• Drivers: 2x 1000mA dimmable Buckpucks, 1x 500mA dimmable Buckpuck = $50 for all three
  
• Bergquist pads: 7 x 0.69 = $5
  
• Potentiometers: Salvaged
  
• Potentiometer knobs: hand made from polymer clay ($2 and an oven)
  
• Power supplies: 18V from wife's old laptop, 24V from my old iBook, 2x12V $30
  
• Container for power supplies: $15
  
• Timer power strip: $25
  

Total Cost:

Supplies about $250 + Time spent building, designing, thinking – enjoyment, satisfaction = +$1,000,000

If only it was that easy to make a buck.

 

 

DESIGN

 

 

 

I used Google Sketchup to design the LED layout, housing, and mounting.

 

It took a very long time to measure out and recreate the heat sink that I salvaged, but it was worth it. This long initial step is what made the whole design possible. I figured out that every aspect was accurate to within 250 microns!

 

The first concept for the housing used acrylic would have been purchased. It also depended on finding 2mm spacers. It didn’t take me long to realize that no hardware stores in the US seem to carry metric nuts and bolts. I had to dig through a bunch of old computer components in order to find appropriately sized hardware. I needed to change my design.

 

 

Over the course of several weeks and at least fifteen iterations, I came up with this model. The little bins on the sides are for the drivers. The holes on the opposite side are for the potentiometers.

 

 

I changed the layout of the LEDs a little in later designs. There are seven total: two Neutral Whites, four Royal Blues, and one Cool Blue. One of the LED gurus I chatted with about my project informed me that the heat sink I have is an amazing insulator compared to most. He added that I could probably line the whole thing with emitters and they’d still stay cool enough to last forever. So, I decided to add another and form them in a hex pattern. The closer LEDs are arranged, the better color blending and less color shadowing you get.

 

 

I came up with a layout design to apply to the acrylic before cutting and measured out everything to the millimeter on my sheet of acrylic, but soon found out that the pieces really need to be measured and cut one by one. The act of cutting alters the measurements by one or two millimeters on each side, which cuts into the measurement next to it.

 

 

 

After I had the main housing together, I realized that this thing wasn’t going to just hover in space. I had to come up with a way to mount it over my tank. The ceiling in my office is way too high for my to reach. So, I decided to go with a leg method. I had to make a lot of measurements of even had to build a model of my picotope in SketchUp in order to really figure out how I wanted to do it. Measuring out these pieces on the raw acrylic required the use of a protractor.

 

Here's a little movie of the complete housing with splash gaurds.

 

 

 

HOUSING

 

 

To cut the acrylic, I used a small hand saw.

Cutting acrylic with a handsaw is a HUGE PITA!

This took me several weekends and produced lots of dust. It's nasty stuff. Any future builds will likely be made with precut acrylic, or I'm going for a power saw of some sort.

 

I then used two different grits of sanding sponge to soften and clean the freshly cut edges.

 

 

A few measurements and some drilling later and I came up with something that looks like a TIE Fighter.

 

 

The driver housing was a challenge. It took me several days of super gluing, ripping apart, measuring, drilling, etc. etc. etc., repeat, repeat, repeat to get it right. The measurements were a little too tight. I ended up having to shave off some of acrylic with my knife in order for everything to fit properly. You can see I left room in the back for the wires to hang down and the made a long thin piece that screws down to secure the drivers in place. For this project I’m used two 1000mA Buckpuck and one 500mA BuckPuck.

 

 

Cutting the housing mounts took a bit of thought and careful measuring. Another week, a lot more sawing, and a little drilling produced this.

 

 

 

More sawing and drilling and I’m almost done with the housing. The splash gaurds on the side are mostly ornamental. I say, one of the satisfying moments of this build was when I was finally able to pull the protective layer off the clear acrylic. Though, I knew I couldn’t do that until almost the end. At this point my wife pointed out that my light was looking less like a TIE Fighter and more like an Imperial ATAT.

 

 

 

 

Time to have fun with electric stuff!

 

 

I mounted the LED’s to the heat sink with Bergquist Thermal Pads purchased from Nanotuners, and wired them up with 22 gauge wire and 60/40 rosin core soldering wire and a 60 watt soldering iron.

 

 

The wire lengths were carefully measured out and immediately tagged (e.g. RB4 to – driver, or NW1+ to NW2-, etc.) with some tape. These tags indicated exactly where the wire went in the array and made soldering the wires a brainless task. You can see in the above image that I used the slots cut into the heat sink to hide the wires and keep them from getting out of control.

 

 

 

The LED’s were tinned before being mounted to the heat sink. Also, the wires were tinned before being soldered to the LED’s. Finally, I wired up the drivers to the LED’s and potentiometers. All LED channels and potentiometers worked perfectly while testing. I ran into a hang-up with the fan though.

 

 

I had two salvaged 12 volt power supplies and tested both of them with the fan, but nothing happened. After using some batteries, I realized that all three were dead. So, I went to the store and purchased two new 12 volt power supplies and one new fan. The original fan was 60mm. Unfortunately, no one seems to sell 60mm fans anymore. Luckily, I made my housing 85mm wide. So, I was able to get an 80mm fan. It’s clear and has some blue LEDs on it. I had to saw a few more pieces of acrylic to make the fan fit on the housing.

 

 

 

POWER SUPPLIES AND TIMERS

 

 

I purchased a container to keep the timers and power supplies safe and organized. A few holes were drilled in the top and bottom to allow for ventilation. The blue LEDs and fan are on one timer and the white LEDs are on another timer so that I can get a dusk and dawn effect.

 

 

I salvaged a 24v power supply from my old iBook G4. Another was 18 volt salvaged from an old PC laptop that my wife owned before we got married. I had to purchase the last two 12 volt power supplies (wall warts) since the ones I salvaged turned out to be dead.

 

 

 

POTENTIOMETER KNOBS

 

 

The potentiometer knobs became quite a conundrum. I originally wanted to find some neat white knobs. I searched the internet for quite a while tring to find the perfect knobs, but after getting the salvaged potentiometers, I realized that I wasn’t sure about their exact size and had no idea what kind of knobs to order. It was becoming a real pain.

 

Creative Mind + Cheap + Frustration with Current Options = DIY

 

 

I have a bunch of polymer clay laying around for making sculptures and decided it would be the perfect material to make my knobs out of.

 

 

 

FINALLY!

 

CORAL PICS AND DISCUSSION

 

Here’s and example of the pop I’m getting out of the Royal Blue/Cool Blue combo. I gotta say, the cool blue addition really adds a nice effect. But be warned, one cool blue can go a very long way. It’s more than enough for my array of seven LED’s. If it's turned up too high, the tank gets way too cyan.

 

 

Here’s a shot of my Crown Royals with all three colored LEDs on it. You can see I’m getting a much warmer effect from the Neutral Whites. The purples of this coral look much nicer and the all of the warmer colors such as reds and oranges are really showing up much better. I’ll never go back to using Cool White LEDs. I found them to make the tank too icy feeling.

 

 

 

CONCLUSION

I really had a blast making this light. Just yesterday I looked at my tank with the lab and office lights off and the glow was ten times more intense. The whole experience has really inspired me to take on more DIY projects. I’ve found that if there’s something I’m not sure how to do, there’s a youtube video out there with an expert explaining it step by step. I’d like to thank my friends in the N-R lighting forum and especially Evilc66 for answering all my noobish LED questions. Without his help and pioneering spirit in the realm of LED, none of this would have been possible.

 

Microscope out!

[jdl]

macgyver, star wars,power tools, diy led...BEST THREAD EVER!!!!!!

 

once again micro you amaze us. congrats and thanks for breaking it down for us technically challenged. i understand the led build so much better now.

[Mr. Microscope]

macgyver, star wars,power tools, diy led...BEST THREAD EVER!!!!!!

 

once again micro you amaze us. congrats and thanks for breaking it down for us technically challenged. i understand the led build so much better now.

Thanks jdl!

 

Yeah, I knew absolutely nothing about LEDs when I started. Most of what I learned from this site is in there. One of the things I left out of there was a diagram of the circuits. I'll be adding that later along with an explanation of how to pick a power supply (voltage Vs. amps, etc.).

[jdl]

ive been lurking around lately looking at the par bulbs and i dont like the height they need to be at. wont work for me. my buddy is an electronics whiz. he told me to find some sort of plans and he could fab something up for me. i have been collecting similar parts to yours. i think im giving him this plan if it is cool with you. i still need a lot of parts.

[Mr. Microscope]

ive been lurking around lately looking at the par bulbs and i dont like the height they need to be at. wont work for me. my buddy is an electronics whiz. he told me to find some sort of plans and he could fab something up for me. i have been collecting similar parts to yours. i think im giving him this plan if it is cool with you. i still need a lot of parts.

Awesome! Glad I could inspire. Take 'em and run!

[jdl]

do you know what the total overall weight is?

[Mr. Microscope]

Hmm, well it's not super heavy, but it's definitely solid and sits firmly on the tank. I have no idea about the exact weight though.

[Mr. Microscope]

So, one of the BuckPucks on my setup blew back around the end march. I've heard from several sources that BuckPucks are unreliable, but there just isn't any alternative with a dimmable option for driving such small amounts of LEDs. Luckily, I was able to order one fast. The way I built my light made it easy to take out and replace. I'm back on the road.

 

The blues were definitely enough PAR for my corals for a couple weeks, but I guess the whites offer something that the blues don't. After putting the light back on the tank with the whites on, my Xenia started pulsing like I've never seen before. In the past, I'd only seen it pulse towards the end of the day during the sunset phase. After the fix, they pulsed all day! They were going so strong, that I thought my pumps off.

[evilc66]

It's the 1000mA Buckpucks that can be a little unreliable. The 700mA versions and lower are better.

[Mr. Microscope]

Good to know. Thanks!

[Mr. Microscope]

So, I finally came up with a wiring diagram. Here it is:

 

[evilc66]

The wiring diagram for the LEDs is very, very wrong. On the royal blue LEDs, you have them wired up in a very odd series parallel arrangement that will short the Buckpuck. The whites are run in parallel. Did you intend for that?

[Mr. Microscope]

The wiring diagram for the LEDs is very, very wrong. On the royal blue LEDs, you have them wired up in a very odd series parallel arrangement that will short the Buckpuck. The whites are run in parallel. Did you intend for that?

LOL! I just saw this. No, I had them wired correctly, just drew the picture wrong. Oh well, you get the idea. Thanks for pointing it out though.