| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device that can keep a high- pressure discharge lamp like a high-pressure sodium lamp lighting without fading out at an instantaneous power failure. SOLUTION: A control power supply circuit 6 obtains operational power for its first and second control circuits 4, 5 by accumulating power in a filter capacitor C2 with induced electromotive force generated at a secondary of a transformer T1. A starting power supply circuit 7 obtains operational power for its first and second control circuits 4, 5 by accumulated power in the filter circuit C2 with ripple flow output rectifying an alternator Vs at turning on. Therefore, since the capacitance of the smoothing capacitor C2 of the control power supply circuit 6 is set at a higher value needed for the first and second control circuits to operate at a normal time when power is supplied from the alternator, a step-down circuit 2 can work at an instantaneous power failure, so that a high-pressure discharge lamp LA can be kept lighting without it fading out. |
