| 摘要 |
PURPOSE:To provide a fluorescent lamp lighting device excellent in general purpose applicability for numerous kinds of fluorescent lamps by changing a DC flowing in a control coil so as to control inductance of a choke coil. CONSTITUTION:A circuit comprises a high frequency inverter 23 where a commercial power source 21 is used as an input source; a choke coil 37 (L-1-L-n) connected between one end of an output of the high frequency inverter and a load wiring system 24; (n) fluorescent lamps (FL-1-FL-n); and a capacitor 27 (C-1-C-n) connected in parallel to the fluorescent lamps and constituting a direct resonance circuit together with the choke coil 37 (L-1-L-n). The choke coil 37 constitutes a variable inductance 25 which can be varied by a DC (i) flowing in a control coil 41 (M-1-M-n) disposed in magnetic paths having a common impedance value. A switch circuit 30 is incorporated for selecting a DC value flowing in the control coil 41 from four predetermined DC current values. |
