Überwachungsgerät für eine Leuchtstoffröhre

摘要

A control apparatus of fluorescent lamp detecting an end-of-life state of a fluorescent lamp for making it possible to have suitable countermeasures taken. In the control apparatus, a load circuit is formed of a capacitor connected between filaments of a fluorescent lamp and a choke coil connected in series with the filament, and there are provided a detection coil for detecting a tube current flowing through the load circuit and a detection circuit receiving an output voltage of a rectifier circuit rectifying the output of the detection coil for detecting a rise in the output voltage occurring when the output frequency of an oscillation circuit is modulated by a modulation circuit.