- Tungsten: As the electrode material, tungsten is likely to sputter on the surface of the tube. It is the black coating near the end of the tube.
- Na: When Na diffuses into the arctube, the tube will get dark. This may occur near the center of the tube, which has the highest temperature.
- Na outside of the arc tube: If the bulb gets dark, it is likely that Na has leaked from the tube and reacted with the glass, leaving brown stains.
When I calculate the voltage drop, should I use the entire load or calculate the voltage drop after every LED light?