POWER SUPPLY DEVICE FOR OUTDOOR ILLUMINATION, ROAD LAMP, AND TUNNEL LAMP

摘要

PROBLEM TO BE SOLVED: To provide a power supply device capable of dimming light while guaranteeing energy-saving performance without giving a user a sense of discomfort, in stepwise dimming control of outdoor illumination.SOLUTION: A power supply device 1 for outdoor illumination comprises: a dimming control part 3 having a dimming target decision part 334 deciding a target dimming rate from an inputted dimming input signal, a transition time period decision part 335 deciding a transition time period in which a dimming rate decreases from an initial dimming rate to the target dimming rate on the basis of a dimming reduction amount from the initial dimming rate to the target dimming rate before the decision of the target dimming rate, and a dimming command output part 336 changing a dimming command value according to the target dimming rate or the dimming reduction amount and the transition time period, the dimming control part 3 being configured so that the transition time period becomes longer as the dimming reduction amount becomes larger; and a power supply part 2 supplying an output power depending on the dimming command value to a light source 4.