DIY LED Lighting: Manufacturing

LED lighting idea appeared in my mind since I was coinciding too often with LED lighting and the aquascapers using LED lighting. Therefore, I decided to have a LED lighting. Then I decided to make my own LED lighting in DIY style to try the system with my design of colors and wattage. As usual, I intended to complete the project at a low cost. (But I didn’t.)

First, I ordered the LED beads, star PCBs, 45° lenses, thermal paste, LED drivers, soldering wire, and other consumables (wires, screws, drill bits, etc.) Most of them were from the famous website of China origin. I first planned to use the LEDs grouped by 6. So, I ordered drivers from a local seller as 6x1W. I ordered more than 50 LEDs to be used in my 36W Power LED lighting system with cool white, deep red, royal blue, and full-spectrum wavelengths. At least they were described as they are in those spectrums in the listings. I can’t check and confirm if they are or not. I should trust the sellers and I did it. Lenses, star-type PCB heat sinks, and thermal paste were also from the same website. The rest were from the local sellers or companies. But in the local market, there are many types and too many Chinese materials. Therefore, the drivers I bought were also Chinese-originated. Chinese goods are always cheaper and come with many choices. Because of this reason I preferred them also for the drivers again. You can find products with different qualities at cheaper prices.

After receiving all the materials and equipment, I started to assemble the LED beads and Star-type PCB heat sinks. I used thermal paste between the beads and the heat sinks to have a better heat transfer capacity during the operation of the lighting system. Then I measured and marked the location of each LED where they will be mounted on the aluminum cooling block. The LED locations are defined by using the basic geometry and considering that I will use 45° lenses with a 45cm height from the tank bottom. The bottom width is also considered. After marking the locations, I have tested all the LEDs soldered on the heatsinks with an old cellular phone charger. They all done well. Then it was the drivers’ turn and BOOM! In the first trial, the drivers exploded and the main fuse of my apartment went down. It was nighttime and suddenly everything went dark. I used the light of my phone to reach the fuse and turned it on after removing the driver from the line. Then I tried with another one with too high attention and this time it was OK. But another problem raised after, I realized that the drivers were not 6x1W, they were 3x1W. The seller sent to me the wrong type and I can’t finalize the lighting with the materials I have. This was the Failure #1. I put the drivers back and returned to assemble the LEDs with heat sinks over the pre-defined locations using thermal paste in between the aluminum block and Star PCBs. And now they were ready to be screwed over the block. This was my Failure #2, because after screwing I couldn’t attach the lenses. The screw heads were preventing the lens to be attached properly. I know that I may glue them as many other people already used with an epoxy or cyanoacrylate adhesive on their DIY systems but after I talked with an expert on that kind of LED lighting systems he strongly suggested to me to use screws or bolts to attach them since the heat will be a problem for both kinds of adhesives in the long run. He was right about his suggestion. I tested cyanoacrylate with heat and I can say it is not proper to be used in high-temperature environments.

After 2 fails which caused more cost and time, I ordered 3 more drivers but this time closed type and 18x1W capacity and 7 pieces 6×1 serial PCBs. (1 spare driver and 1 spare PCB) I had to remove all the screwed LEDs from the aluminum block and then the beads from star PCBs and to re-solder to the new PCBs. I used the thermal paste again while attaching the new type of PCB over the aluminum block and fixed them with screws. Wiring and soldering followed to connect the drivers with the LEDs. I take extra care with the electrical insulation to prevent any accidents that may cause problems due to high voltage. For the electrical insulation, I preferred to use one commercial insulation spray which has a capacity of insulating 40.000V at 1mm thickness as described in its technical specifications. I applied to all open poles. Also, the high-capacity wire is used (thicker than enough) to prevent any fire risk due to over-heated wire. “Each type of equipment that we made as DIY should be also safe even if it will cost a little more.”

After spending many hours (~15 working hours), efforts, and money on the new DIY LED lighting, finally it was ready to use in the aquarium. The total cost of the system was less than buying a brand new lighting system. If I am not counting the efforts and the disappointment that I had because of the failures. But it is acceptable while considering this is my first trial and the fails are caused mainly by the material inconsistency or defects.

After all, there are some DOs and DONTs for this project you can find below as a summary for your reference that you may use in your projects. You can find also my assembly scheme for your reference.

Note: Please be aware that the system tests are not yet finalized for efficiency.

Tank Size: 80x40hx30 cm
Tank Volume: ~90 liters
LED Power: 36W
Watts / Liter: 0,4
LED Driver: 2 each of 18x1W 350ma
LED numbers: 9x1W Deep Red(660nm), 9x1W Royal Blue(450nm), 18x1W 6500K cool white

As per my first observations and the experiences during the manufacturing of the DIY LED lighting system;

LED Lighting DOs:

  • Try to use a ratio of LEDs 15% Deep Red, 15% Royal Blue, and 70% Cool White to have more light intensity and photosynthesis efficiency as well both for visually impressive aquarium with good plant development. You can also use 2% UV, 1% red, 1% green as per your choice.
  • Use narrower angle lenses for only deeper tanks (higher than 50 cm), otherwise, you will have focused lights with different colors at your tank which will create algae problems with unpleasant views.
  • For the risk of electricity try to use more drivers to reduce the maximum voltage of the driver output. I used 2 pieces of 18W drivers with 350ma current and ~50-60V output and believe me they are biting if your hands are wet without completing the loop. I believe in case the loop is closed it will hurt seriously. (I made a quick search and it seems 350ma is enough to seriously hurt someone with enough voltage; please correct me if I am wrong)
  • Use Aluminum block with fans to cool the LEDs and extend the lifetime.
  • Use Serial PCBs to have less screwing load and reduce the risk of lens incompatibility.
  • Use thermal paste both between LED beads / PCBs and PCBs / Aluminum block.

LED Lighting DON’Ts

  • Don’t let water enter the circuit while operating your lighting to prevent corrosion and loss of LEDs. Better to use insulation spray.
  • Try not to prefer smaller aluminum cooling blocks because they will quickly get heated and reduce the LED lifetime or may cause loss of LEDs.
  • I suggest not using epoxy and cyanoacrylate adhesives for attaching LEDs on the cooling block in case you are not sure about the heat will be loaded on the aluminum block. To be on the safe side I strongly suggest screwing or bolting.
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