I was reading the LED light bulb project that Belza built. Most of this was written in Czech, so you may want to run it through google translate. He builds a 240 lumen LED light using a regular screw in plug from the end of a light. At the end he confirmed what I have been saying in the past. I quote:
I was delighted at first – LED bulb shoned brilliantly and I assumed that it will be long. But later some LED were damaged. Therefore I added the Zener diodes to the circuit. After them the lamp shining if one or more LEDs are defective. Also damaged LEDs could be easily identified. When I changed after seven months the damaged LED again I noticed that the new LEDs luminosity was significantly higher than old – see Figure 6. I used the same LEDs as before, I bought them about the 150 pcs. Since then stopped another 6 LED light. Finally, I replaced the LED bulb back in a compact energy saving lamp. I think that LED lighting technology would also like some time before it is sufficiently reliable and cheap. If you aplly the (cheap) LEDs to lighting, here are a few suggestions:
At first do not use cheap unbranded LEDs – lifetime specified by the manufacturer is highly overrated. Second – LED current will be less than the manufacturer specifies a maximum. With less current the lifetime dramatically extended.
In other words, the cheap unbranded LEDs don’t last as long as the claims made by most makers and sellers. And if you run them at 30 mA, they may stop working, so keep the LED current below the 30 mA maximum. I’ve found that 20 mA is a good point to aim for. A little above or below doesn’t make much difference. And if you want to use the LEDs for lighting which is powered on for an hour or more every day, then the LEDs should be good quality brand name LEDs.
Back to experimenting…
