LED for Dummy

[hlem]

I'm a true believer of LED as the future of reef lighting. But a lot of people don't understand it because there is simply too much info to grasp or dont want to jump on it because of its rather large price tag.

 

Well, here is a quick tutorial for the folks who want to learn, try, and/or take a leap into LED for very little cost.

 

I'm going to use my recent DIY moonlight as the example for this thread. Moonlight LED

 

I decided not to use the star type LED because it's much more expensive and require more work to put together. The star type led you get from RapidLED or any other aquarium LED site is just an LED bulb pre-soldered onto a star shape Printed Circuit Board (PCB). With this you have to drill into the main heat sink, use thermal adhesive per star and screw it on. Or if you dont want to drill into the heat sink, you have to use the permanent thermal adhesive to "glue" the star onto the heat sink. lots of work. i've done this and it takes up majority of the time. And once you attached the these LEDs onto the heat sink, you'll then have to connect (solder), with wires, each and everyone of the LEDs together. This also take a bunch of time.

 

Parts:

Driver $7 - can drive 4-6 1W LEDs @300mA

LED heat sink PCB $5. Designed for 5-1W LED serial connection

LED $11 - Blue 1W LED @ 300mA

2-parts permanent thermal adhesive

Soldering stuff

 

Putting it together:

1. Find the negative and positive terminal on the led. using one of this... tester.

2. Lay the LEDs onto the PCB board, making sure to line up the LED+ and LED- to the PCB+ and PCB- for each LED slot. so you know where each LED will go when you start gluing it on.

3. Mix the 2-parts thermal permanent Adhesive, only a little at a time as it will dry up and become useless.

4. One at time, apply a tiny bit of the mixed adhesive on the bottom of the LED and attach it to the PCB, press and hold for a few seconds until it stick. Only apply the adhesive to the center of the LED and not the positive and negative terminal. Make sure everything is still lined up properly.

5. Repeat for all LEDs

6. Let adhesive dry up for ~5 minutes. Check it and make sure the LED is attached onto the PCB board.

7. Solder the LED+ and LED- onto the PCB board. You can check if it is soldered properly by using the LED tester.

8. Connect (solder) the Driver cable to the PCB board, red to positive, black to negative.

9. Connect the power cable to the driver (wall plug to driver), doesnt matter what color cable it is as long as NOT THE GREEN ONE if you're using a 3 prong plug. make sure you FULLY cover the connection with electrical tape. DO NOT LEAVE THE POWER CABLE and driver CONNECTION EXPOSED. IT IS VERY DANGEROUS AS IT IS COMING FROM THE WALL.

This 5 bulbs LED unit cost about $25 in parts, excluding adhesive, soldering tools and materials and power cable. I purchased everything from Ebay. You can probably find cheaper price if you search and barter around.

Edited May 25, 2012 by hlem

[Guest thefishman65]

I can't find it in information the seller posted, but are these blue or royal blue - any coral pop?

I think these are the same LEDs the company I work for has used in the past. If so they are supposed to be solder on (not thermal adhesive). I don't see why the adhesive won't work, but do you have anything to back up that choice?

 

For those considering LEDs. For moon lights where you don't need a lot of light these are good (or as mentioned in the other thread maybe too much). The thing to watch for is effieciency. You can get three times the light (maybe more) for the same power using more efficient LEDs. The XT-E produce 150 watts at about 1 watt. Does it matter? You need three of these or 2 extra watts to make the same amount of light,

 

2 LEDs * 8 hours a day * 365 days / 1000 watts = 5.84 kilowatts. 5.84 kilowatts * $0.12/kilowatts = $0.70 per year.

 

If the better LED cost $4 and you can use three of the $1 dollar cheap LEDs you can see it does not take long to make up the difference of a $1. Typically you can have low upfront costs or low operating cost.

[hlem]

I can't find it in information the seller posted, but are these blue or royal blue - any coral pop?

I think these are the same LEDs the company I work for has used in the past. If so they are supposed to be solder on (not thermal adhesive). I don't see why the adhesive won't work, but do you have anything to back up that choice?

 

For those considering LEDs. For moon lights where you don't need a lot of light these are good (or as mentioned in the other thread maybe too much). The thing to watch for is effieciency. You can get three times the light (maybe more) for the same power using more efficient LEDs. The XT-E produce 150 watts at about 1 watt. Does it matter? You need three of these or 2 extra watts to make the same amount of light,

 

2 LEDs * 8 hours a day * 365 days / 1000 watts = 5.84 kilowatts. 5.84 kilowatts * $0.12/kilowatts = $0.70 per year.

 

If the better LED cost $4 and you can use three of the $1 dollar cheap LEDs you can see it does not take long to make up the difference of a $1. Typically you can have low upfront costs or low operating cost.

 

The choice to use permanent thermal adhesive is because there is no way to solder the LED to the board. I would have soldered if I could. But it is simply impossible to solder since the LED needs to sit on top of the PCB part. I believe these are blue, 460-470nm. They do have RB as well. I just got the cheaper one just because it was just for moonlight. I PM'ed the selling asking after. They do make the coral pop. I've tried it already

 

As for efficiency, (not sure what you are using to determine this) and I dont know about the XT-E. But i'm looking at CREE XP-E on RapidLED. It says 39.8lm@350mA. This 1W LEDs puts out about 50lm@300mA.

 

I'm sure CREE is more efficient when you get to higher Wattage. but these are simply way easier to build than regular CREE stars.

[hlem]

oh.. i just notice something on RAPIDLED... look at their moonlight kit... notice something? the LED? on the starboard?

 

but yea. this isnt meant to be what led is good/bad. simply showing how easy it is and cheap, and get some knowledge and experience with LEDs.

Edited May 25, 2012 by hlem

[Guest thefishman65]

I realize the LED is supposed to be soldered to the board. I am just wondering where you got the idea for thermal adhesive and how well it will work.

 

I did not mean to imply good or bad. Just trying to keep folks in formed if this is the first thread they read.

CREE 39.8 lumens / (350 ma * 3.1 volts - typical) = 36.7 lumens/watt

CREE 39.8 lumens / (350 ma * 3.9 volts - max) = 29.2 lumens/watt

Unknown 50 lumens / (350ma * 3.4 volts) = 42.0 lumens/watt

Unknown 50 lumens / (350ma * 3.6 volts) = 39.7 lumens/watt

I wish they had link to datasheets. They certainly seem better than the CREE.

[hlem]

I realize the LED is supposed to be soldered to the board. I am just wondering where you got the idea for thermal adhesive and how well it will work.

 

I did not mean to imply good or bad. Just trying to keep folks in formed if this is the first thread they read.

CREE 39.8 lumens / (350 ma * 3.1 volts - typical) = 36.7 lumens/watt

CREE 39.8 lumens / (350 ma * 3.9 volts - max) = 29.2 lumens/watt

Unknown 50 lumens / (350ma * 3.4 volts) = 42.0 lumens/watt

Unknown 50 lumens / (350ma * 3.6 volts) = 39.7 lumens/watt

I wish they had link to datasheets. They certainly seem better than the CREE.

 

yea, they dont have datasheets for these LEDs. When I get another tank, I'm going to do all ebay LEDs and if you like, you can come and see/test par and compare.

 

These are good alternatives to CREEs at a fraction of the cost. like i said, if anyone want to dive into LEDs and not want to spend a ton, then this is a good starting point, especially some driver they offer is for driving, 1,3,5 LEDs instead of ~12 minimum with the CREE's. So you can start off as little as you want. and move up slowly.

 

 

[Guest thefishman65]

It would be interesting to compare lumens/watts of these vs Cree. It is certainly easier to start with these - I am just worried about long term electrical costs. Do you have any of these that you did not attach to the board? I think I have a Cree blue. We could compare lumens/watt at several distances and see what happens.

[hlem]

It would be interesting to compare lumens/watts of these vs Cree. It is certainly easier to start with these - I am just worried about long term electrical costs. Do you have any of these that you did not attach to the board? I think I have a Cree blue. We could compare lumens/watt at several distances and see what happens.

 

It'll definitely be a good experiment. I have just the above configured. no single LED. But can easily cover 4 up and use only 1. I dont have any measuring devices tho. You are welcome anytime to come and test it.

 

is the cree blue 1W? these are only 1W, so it'll be better if the cree is also 1W.

[Guest]

LED's are super easy. My DIY has been running 2 years now and still very powerful. You will not have T5's or MH lighting hardly at all within the next few years. I think you will see many companies start to phase out of their older products. LED's last a long long time, offer dramatic colors, can be used in more types of lighting senerios with computers, reduce energy cost and offer reefers a new and better way to upgrade and make the hobby more interesting. What isn't to like about LED's. They really are not that expensive if you look at the big picture. Read up on LED's and learn as much as you can because it will soon take over. I have already seen a huge difference in the past 2 years. Many new aquarist and WAMAS memebers I have talked to are now using LED's.

 

It would be an interesting poll to see what types of lighting people are now using. I bet the results would be shocking. I bet 2 years ago less than 5% of WAMAS members had LED lighting. I bet its now over 40% and maybe even over 50%.

 

LED's are now the centerpoint and main focus in almost every hobby catalog. That should tell you something.