It’s actually a good example of upcycling. The cans have standard sizes and are available nearly for free in most parts of the world. The can houses one or two tiny LEDs mounted on an IMS (insulated metal substrate) circuit board in the concave space at the bottom of the can. The metal of the can works as a heatsink for the 0.5 W LEDs. The total BOM is really low if large quantities of the necessary parts (PCBs, LEDs, acryl covers) are ordered and they are easy to assemble. The selected LEDs (Nichia NFSL157AT-H3) have a high color rendering index and are therefore good for reading and indoor use.
Here’s an image of two 0.5 W LEDs on an IMS PCB together with current limiting resistors:
The 0.5 W LEDs which are soldered to an IMS circuit board and then glued into the concave bottom part of the can are really tiny:
This is the first prototype. An acryl cover protects the LED from dust and moisture. The acryl covers are now laser-cut and therefore fit much nicer.
Currently the lights are USB-powered from a computer or a small wall adapter. This makes a great camping light as was tested out at the Chaos Communication Camp 2011.
In the next step we will integrate more electronics: a small LiFePO4 battery and a charge controller. This will allow charging from a solar panel or the USB port.
The animation and rendering is done with Blender. I followed an excellent video tutorial about cans in Blender which can be found here.
The goal is to make an instruction video with blender in the future.