| 摘要 |
PROBLEM TO BE SOLVED: To provide electric discharge lamp lighting equipment, which can suitably set up preheating current of a filament even in case that dimmer control is performed. SOLUTION: A rectifier circuit 2 rectifies voltage of an alternate-current power supply 1, and a smoothing circuit, which consists of a coil 3 for smoothing and a smoothing capacitor 4, smoothes it to output direct-current voltage. By carrying out ON-OFF of switching elements Q1 and Q2 by turns by a control signal of a control circuit 6, high frequency voltage V1 is supplied to an electric discharge lamp 5. A coil L1 for limiting current and a capacitor C1 for preheating form a LC resonance circuit, and it impresses high voltage between a filament F1 and F2 . Filament preheating circuits 7a and 7b, which heat the filaments F1 and F2 , are connected to secondary side windings Ta and Tb of a filament transformer Tr. A series resonance circuit, which consists of reactors La and Lb and capacitors Ca and Cb, is connected to each the preheating circuits. |
