effected by the load introduced by the electric discharge and the feedback from the emitter of the transistor used to generate the pulse a capacitor is serially connected in the lamp circuit to inhibit the flow of dc current therein application_number US 88397286 A description now an embodiment of the present invention will be described in detail below with reference to the accompanying drawings fig1 is a circuit diagram of a lighting device for a fluorescent discharge lamp according to this invention the circuit shown in the diagram is broadly divided into a power source circuit and an oscillating circuit and 2 3 4 and 5 collectively stand for a noise filter 6 for a full wave rectifier 7 for a smoothing capacitor 13 for an oscillating transistor 16 for a feedback signal feeding capacitor 17 for a feedback signaling coil 18 for an oscillating coil 19 for a resonating capacitor 20 for a dc inhibiting capacitor and 21 for a fluorescent discharge lamp the power source circuit is composed of a filter comprising a capacitor 2 and a coil 3 and a filter comprising a capacitor 4 and a coil 5 possessing two different frequency bands determined by the inductances of the coils 3 and 5 and the capacitances of the capacitors 2 and 4 this power circuit is connected to an ac power source through the medium of a fuse 1 a full wave rectifier 6 connected through the medium of these noise reduction filters and a smoothing capacitor 7 parallely connected to the output terminals of the full wave rectifier 6 the oscillating circuit is composed of a control circuit which is formed by connecting a base voltage feeding resistor 8 and a feedback signal feeding coupling capacitor 11 to a.