LED room light - selfmade

(Deutsche Version) At Pollin, there are COB-LEDs for sale (Pollin). The great thing about them is that they don't need any resistor or anything else, you just have to apply the suitable voltage and a heat sink.

560 lm is quite a lot, I will compare different light sources in a different post. The great advantage of LEDs is that they are effective and have a very high life time so maybe the future belongs to LEDs. The only problem with this LED is that the light comes out of a very small area and the LED is very bright and is eventually dangerous for the eye. Therefore, I had to build a lamp shade. I used greaseproof paper. The instructions are very simple, you only should ensure that b > a/2, otherwise there will be a hole in the middle.

Cut along the red edges. Afterwards fold the vertical dottet lines about 90° so the paper makes a closed cylinder. Afterwards, the flaps have to be folded over and the whole thing is some kind of bucket which can be put over the lamp. The final result is the following: