| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light emitting diode lighting device that suppresses trouble with higher harmonics of an input current and prevents a flicker of light by stabilizing circuit operation. <P>SOLUTION: The light emitting diode lighting device includes: a DC power supply DC having a rectifier circuit DB for rectifying an AC voltage, and a smoothing capacitor C1 for smoothing a DC output voltage of the rectifier circuit; a step-down chopper SDC having input ends t1, t2 connected to the DC power supply, output ends t3, t4 connected to a load, and an output capacitor C3 connected between the output ends; and a light emitting diode LED connected as the load to the output ends of the step-down chopper so as to be turned on. The smoothing capacitor has a capacitance set such that an input current waveform to the step-down chopper has a fifth harmonic rate of 60% or lower over a predetermined period and that the voltage of the smoothing capacitor is higher than an output voltage of the step-down chopper over an entire AC voltage period. <P>COPYRIGHT: (C)2012,JPO&INPIT |
