| 摘要 |
<p>PURPOSE: To stably start-light a light source which requires a current larger than the rated value just after starting. CONSTITUTION: In a power unit connected to a power supply circuit having relatively large internal impedance to perform operation of lighting a light source required for power of the rated or more when starting and limiting power supplied to the light source when a power supply voltage is lowered below a prescribed voltage or less, power limiting action is inhibited for a prescribed period of starting. Particularly in the case of lighting a high pressure discharge lamp by a storage battery 1 of an automobile, power of the rated or more is supplied when starting, thus to decrease input voltage of a lighting device 2 to prescribed voltage E1 or less, and even at this time, for a period a timer circuit 82 operates, the power limiting action is inhibited by a power supply detection inhibiting circuit 83.</p> |
