| 摘要 |
<p>The lighting device for a discharge lamp includes a bridge type rectifying and converting circuit CR1, feedback circuits FB1, FB2, a chopper circuit CR2, a charge circuit CR3, a resonant circuit CR4 resonates with a high frequency signal and lights discharge lamp DL connected to the output end by the resonant voltage, an inverter circuit CR5 which converts the DC power stored in the charge circuit by an alternate switching action of a pair of switching elements Q1 and Q2 into high frequency AC power, and a switch device connected between a connecting point J3 of capacitors C1, C2 of the charge circuit and a connecting point J2 of a pair of rectifying elements D1, D2. The lighting device for a discharge lamp can correspond to a multiple variation of a power supply voltage by a construction which uses the same switching elements by step-up chopper circuit and by inverter circuit in common and changes duty factor of the switching elements within a predetermined range.</p> |
