DIY LED Aquarium lighting Instructions for a 10W 30 cm Light 1. Disclaimer This DIY project includes electrical and mechanical parts and requires some (relatively little) experience working in these fields. I in no way am responsible for any damages, inconveniences or consequences that you may suffer from this guide. Follow this tutorial at your own risk. It is always important to be wary of the dangers that electronics (especially 110/220V mains) themselves and their combination with water pose. Furthermore, some of the components might be a fire hazard. 2. Introduction LED Lights are power saving and have a very long lifespan. This makes them ideal candidates for aquarium lighting. Additionally, they offer a variety of color spectrums from warm and cool white to blue for marine tanks. Their small size allows for stylish designs and compact lights. Many companies have started producing LED lighting solutions for aquarium tanks of all sizes. However the products are usually very expensive or lack the desired power to replace existing fluorescent tubes. My search for a cheap and aesthetically pleasing lighting solution for my three 30x30x30 cm turned out in disappointment. So I decided to design my own. Being a mechanical engineering master s student I ve had some basics in all required fields and decided to do something practical for a change. The final product came out way simpler than expected, so I decided to follow up the project with a DIY guide for anyone searching for a cheap way to light their aquarium. 3. Pre-Requisites For this light I decided on a single 10W LED and a 30 cm heatsink that cools the LED just enough and acts as the support beam at the same time. These Instructions are based on these specs. The reader may want a different size or more or higher powered LEDs. In that case I highly recommend having at least the same ratio of heatsink area to LED power since the heatsink and LED in this build are very near the thermal maximum. Parts For this build I used: 1x 10W cool white (6500K) 900mA LED (~$2) 1x 10W 900mA LED driver (input 85-265V) (~$4) 1x aluminum heatsink 300x25x12 mm (~$6) 1x power cable (~$5) 2x 1m (or longer) thin insulated wires (I recommend one black and one red) (~$1) Thermal paste (preferably not silver) (~$3) 2x universal screws about 2.5x10 mm (~$1) 10 cm 3:1 6,4 mm shrink tubing (~$1) 10 cm 3:1 3.2 shrink tubing (~$1) 2x 3D printed parts (~$5) Tape Total cost: about $29 Tobias Ammann 1
I got most of these parts imported from China over ebay. If you search on ebay and include international offers you should find pretty much the exact same items at about the same price. Shipping might take a couple of weeks. For the LED and driver: it s important that they have the same current (here 900mA) and wattage (here 10W). The power cable can often be found around the house since some electrical appliances have spares in the box. Usually it is also be sold by your local retailer. The screws can be bought in bulk or sometimes a retailer will sell them by the piece, which should make them very cheap. The 3D printed parts are where it gets tricky. I had a friend create me a prototype and printed the final ones myself after acquiring a 3D printer. The material costs of these two parts together is less than 20 cents. If you don t have a 3D printer and don t know anyone who would help you out you could try 3dhubs.com or contact me. Here is the link: http://www.thingiverse.com/thing:1012774.stl file for printing and.prt files for editing (created with Siemens NX 8.5) These 3D printed parts are designed for an aquarium with glass thickness of 4 mm and a heatsink with a width of 25 mm. Tobias Ammann 2
Tools For this build I used the following tools: Soldering iron Drill with 2 mm drill bit Screwdriver Lighter Ruler 4. Building Instructions 1. Drilling the LED mounting holes The middle of the heatsink is marked or scratched and the LED is placed centered with the two electrical connections longitudinal to the heatsink. Two holes are marked at opposite sides of the LED. Only two screws are needed, but they have to be in opposite corners. Two holes are drilled where marked. The drill bit is chosen a bit smaller than the screws, here 2 mm is used for 2.5 mm screws. Tobias Ammann 3
2. Mounting the LED The LED is prepared with a thin layer of thermal paste on the bottom. This helps to conduct the high amount of energy away from the LED. A 10W LED gets extremely hot and dies quickly if not cooled properly! This layer should be as thin and even as possible. There are many theories on how to achieve this optimally. Further strategies can be found online in CPU die thermal paste application. (My example here probably isn t optimal, but works) The LED is again placed on the heatsink and the two screws are inserted. Some force might be necessary, but the universal screws should cut their own thread in the aluminum. The conical heads of the screws help to apply pressure on the LED and squeeze the thermal paste under the LED. This makes the layer even thinner and more efficient. After the screws are sufficiently tightened the excess thermal paste around the LED is wiped off. 3. Soldering the LED to the Driver The LED is soldered to the 2x 1m Wires. There are indications of polarity (Plus (red) or Minus (black)) on both the LED and the driver. It is important, that the plus on the LED is connected to the plus on the driver (and the same for Minus). I recommend either using a black wire for minus and red for plus (universal coding) or marking them to make sure they are not mixed up. The wires from the LED need to be connected to the Tobias Ammann 4
corresponding wires of the driver. It s important to first put about 5 cm of heat shrink tubing over the wire before soldering since it might not be possible afterward (if the LED is soldered first) Tobias Ammann 5
The heat shrink tubing can be shrunk now or later. For shrinking the heat shrink tubing just heat it with a lighter (don t burn it!) 4. Soldering the 110/240V AC Cable The AC cable is cut so there is as much length to the socket as possible (if there is a plug for an appliance on the end). There should be two or three wires inside. Depending on the LED Driver only two are use (standard is blue and brown). The green/yellow wire should be ignored if it is not connected to the driver (or can be used as ground). The outer shell of the cable will need to be trimmed about 3 cm further back so that the individual colored wires are exposed. These wires will be connected separately to the drivers. They need to be insulated separately with heat shrink tubing so that they absolutely can t touch each other! Theoretically blue and brown can be interchanged since AC is used. An additional large diameter shrink tube is used to cover the intersection. This connection is critical and dangerous! It is absolutely necessary that the two connections don t touch each other and are shielded to anything outside! There is a lethal voltage here! 5. Mounting the Heatsink on the Aquarium In the final step, the heatsink is connected to the 3D printed parts and put on top of the aquarium. The 3D printed Parts should fit perfectly on the heatsink ant the aquarium. It s important, that the heatsink does not fall into the aquarium. Since low voltage is used to power the LED the aquarium might be safe in case of an accident, still I recommend keeping the LED dry at all times! Tobias Ammann 6
6. Enjoy the new light If you followed these steps exactly your LED light should be working great. I still recommend keeping a close eye on the driver, the LED and the heatsink for the first couple of hours. It the driver gets very hot it might be malfunctioning. If the LED flickers, is too dark or does anything else unusual the driver or the LED might be damaged. Touching the driver or the heatsink should in no way cause a shock, if it does, there is something wrong! The heatsink will get quite hot. In the case of this exact build it gets just too hot to hold on to for over 5 second. If it is not that hot after having the LED on for a while or it gets so hot that the 3D printed parts melt something is wrong! For the power of the LED. In the case of a 25L cubic freshwater tank without additional CO2 a 10W light is the maximum I would recommend! As for tank design, keep in mind that a single LED will act as a point light source and cause harsh shadows and reflections. The movement of the water surface will cause a nice ripple effect on the walls and ceiling: this might be desired or not. Thank you for reading this DIY tutorial and please feel free to send me questions/suggestions or especially images of your own build or interpretation of this tutorial! Tobias Ammann 7
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