Solid light-emitting element lighting device and illumination fixture using the same

摘要

[Object] To provide a solid light-emitting element lighting device and an illumination fixture using the same that are able to smoothly change an optical output in sweeping of a PWM signal for dimming. [Means for Settlement] A LED lighting device includes: a series circuit of an inductor L1 and a switching element Q1 that are connected between output terminals of a direct-current power source 1 via a LED module 4; a diode D 1 for regenerating energy accumulated in the inductor L1 to the LED module 4; and a control circuit part 3 for controlling on and off of the switching element Q1. The control circuit part 3 includes a drive signal generation part 34 for generating a drive pulse whose pulse width varies in accordance with amplitude of a load current, and controls on and off of the switching element Q1 due to the drive pulse in an on-period of the PWM signal whose on-duty varies in accordance with a dimming level, the PWM signal being a lower frequency than the drive pulse. An output voltage of the direct-current power source 1 is set to be larger than the load voltage applied to the LED module 4 and to be 2.5 times as large as the load voltage or less.