Are these UV-C tubes meant to be run only on pure AC ballast?

Thread Starter


Joined Dec 16, 2016
I’ve this portable small T5 4W UV-A 300-400nm black light tube lamp with me. I’m trying to see if it’s possible to use a 4W UV-C lamp in the same fixture. But I noticed that the lamp has the violet glow only to one side which makes me think the supply is pulsed DC likely. But I noticed that the tube has started to darken on both filament ends as shown in picture.
Anyone has any idea what might be causing this or is this tube Only meant to be run on an AC type ballast?



Joined Jan 18, 2008
The UVC (254 nm) low pressure mercury lamps I have used ran off AC in ordinary fixtures. To a human, they did not show the luminal bias you describe.