| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an LED lighting device capable of obtaining an optical output equivalent to the case when the LED is turned on by DC smooth voltage while reducing a harmonic component of input current.SOLUTION: An LED lighting device comprises: a full-wave rectifier which carries out full-wave rectification of a commercial AC power supply; a first capacitor connected in parallel to an output terminal of the full-wave rectifier; a switching power supply circuit unit whose input terminal is connected in parallel to the first capacitor; an LED light-emitting unit connected to an output terminal of the switching power supply circuit unit; and a second capacitor connected in parallel to the LED light-emitting unit. The switching power supply circuit unit operates in discontinuous mode. The capacity of the first capacitor is not more than 0.5μF. The capacity of the second capacitor is set so that a ripple factor of current flowing in the LED light-emitting unit becomes less than 1.</p> |
