| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-emitting element lighting device and an illuminating fixture using a DC trigger system, capable of maintaining a high noise resistance by a trigger signal at dimming, and of performing dimming control without a sense of discomfort to human eyes.SOLUTION: A dimming controller 3 continuously supplies a trigger signal for turning on a triac Q81 for a predetermined time period of a time period for making the triac Q81 conductive. A dimming circuit 1d controls a load current while referring to a dimming curve. With respect to the dimming curve, the load current is reduced along a curve represented by a high-order polynomial formula in a region where a phase angle is a first phase angle or more and a second phase angle or less, and the load current is set to a constant maximum value in a region where the phase angle is less than the first phase angle, and the load current is set to a constant minimum value existing in a range of 5%±3% of the maximum value in a region where the phase angle is more than the second phase angle. The first phase angle is set in a range of 40±20°, and the second phase angle is set in a range of 120±10°. |
