| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device of which the detection result is hardly influenced by the length of a tube, a waveform factor, circuit dispersion, and which can be applied to a wide range of discharge lamps. SOLUTION: Tube currents 41 and 42 are partially divided into a positive electrode-side current and a negative electrode-side current by diodes 5 and 6 and input to the primary side of a pulse transformer 7. Since the primary side has a two-wire winding, the negative electrode-side current is inverted, and the second harmonics of flux-coupled common-mode voltages are output to the secondary side. A tuning circuit 8 tuning to the basic frequency of the tube current is connected to the secondary side. Since the balance between the tube currents 41 and 42 is disrupted when emission-less occurs, and the difference between the tube currents is output from the pulse transformer 7 as a basic wave component, it resonates in the tuning circuit 8, and a Q-fold output voltage is output. COPYRIGHT: (C)2008,JPO&INPIT |
