What would be a simple solution for detecting lamp failure in fluorescent tube ECG's?
There are 3 control gears running 6 (40w/4pin) lamps that need to have detection of lamp failure. While ECG's have a simple way to detect failure on the control circuit how would you go around the issue to detect lamp failure with available high frequency outputs?
Current measurement on input side seemed like a decent idea, but the L-N polarity may be reversed - as such that becomes problematic (the inrush current is another issue ~31A / ecg). I can only think of using the lamp output HF side, but am unsure of how to approach the matter in a reliable way with minimal work and off the shelf components.
There are ballasts available with contacts for lamp failure but they tend to be around 80$ as opposed to 15$ for regular ones.