Hello,
I have an issue with a CCFL inverter designed to turn on and dim one UV bulb.
The inverter has been made is China and is based on the chip OB3302 (I have seen some posts about it on this website). There are five signals feeding into the chip: +5V for the logic gates of the chip. +12V to the MOSFETs pumping the transformer. Ground signal. And two control signals - an ENABLE signal to turn the lamp completely ON and OFF, as well as LPWM to control the intensity while it is ON. Presumably the allowed logic level on LPWM, is a 5V amplitude signal. There also is a feedback pin that controls the current of the bulb, with pin CMP/SST.
In some cases, the light turns off after a random amount of time. If I unplug the light and plug it back, it will turn on once again, but still fail after some time. I made sure the bulb wasn't the issue, nor the connecting cable.
Would any of you have a suggestion about what the issue could be?
Thank you very much for your help!