I was looking for an LED light for my computer armoire since I was tired of finding and changing tiny halogen bulbs, and ended up building my own with some parts I had in the garage. It turned out to be very easy to make, and the cost is lower than the ones at the home stores.
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Step 1: Parts
The following parts were used for this project:
- LEDs - 3528 analog LED strip. 300 LEDs on a 5m (16.4') strip. These are 12v DC LEDs. The link is for a soft white one, but you may prefer bright white . I received some feedback that the warm lights gave a green tint to skin, so I ended up with two warm and two bright white strips. There are also 5050 and 5630 LED strips. Those are brighter and draw more power. The LED strips have adhesive backing for easy mounting. This site and this site have good info comparing the LED types.
- Aluminum bar - 1.5" wide x 48" long x 1/8" thick. Here's a lower cost non-anodized one. This is an Anodized one. Here's another one. I used this as a base, but other materials may work. The LEDs do get warm, so I thought the aluminum bar would dissipate the heat better. I had some anodized bar, which has a nicer finish, but is not necessary since this project is mounted out of sight normally. The 1.5" wide bar was fine for 4 strips.
- Power supply. A 12v 3amp supply is enough for one strip of LEDs.
- A terminal connector for the LED strip - 2.1mm x 5.5mm. That link is for a dimmer that comes with one adapter, but you can buy the adapters separately. The dimmer is highly recommended, since it allows you to control the exact brightness easily.
- Some wire to connect the strips - about 6" of red and black. I prefer flexible servo wire.
- Two screws to mount it - I used wide head lath screws #8 x 1/2".
Step 2: Assembly
The construction is fairly easy - some minor soldering is required.
An important note is that I think my LED strip may have been partly used, so I think there are only 264 LEDs in my pictures, and the bar is closer to 47" long. You can use more or less as needed.
The strip should be divided into 4 equal lengths. Make sure to cut on the cut marks on the strip where the solder pads are - every 3 LEDs.
I ended up with two bright white and two warm white strips to balance the color temperature. A full 5m of 3528 LEDs emits about 1,500 lumens. For comparison, a 60w incandescent bulb is about 800 lumens, and a 100 watt bulb is about 1,600 lumens.
The metal bar should be about an inch or two longer than the strip on each side - this allows for mounting holes and power adapter connection.
Since the strips have adhesive backing, you can stick them to the bar while peeling the backing as you go. I put two strips on each edge with the idea that I may need to drill a mounting hole in the middle later. The adhesive on the strips I had seem to be holding, but you can also additionally secure them with glue, zip ties, or twist ties.
The strips need to be connected to the power. They make snap-on connectors, but I decided to solder them together. Since they are all connected together, I just ran jumpers from the strip with the power connector to the other three. I soldered them near the beginning of the first strip to minimize any voltage drop across the strips, but that is not strictly necessary - the strip will still work as one continuous run too. Since they are analog, though, you can connect them anywhere you want.
I used hot melt glue to hold the connector to the bar, but that did not hold. So, I switched to a zip tie - drilled two smaller holes on either side of the power connector.
I drilled a 3/6" hole on each end to mount the bar, and used the two lath sheet metal screws to attach it under the top of the cabinet.
That's it! This was an easy project to put together once the materials were sorted out.