| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an LED lighting device having high efficiency even in the case that the number of LEDs to be lighted is small. <P>SOLUTION: An LED lighting device 1 for lighting an LED 23 has: a first buck converter (a switching element 14, a diode element 15, a coil element 16, and a capacitor element 17) stepping down an input voltage to a first voltage; a second buck converter (a switching element 18, a diode element 19, a coil element 20, and a capacitor element 22) connected in series to the first buck converter, and stepping down the first voltage outputted from the first buck converter to a second voltage lower than the first voltage to supply it to the LED 23; and control means (a controller 30) detecting a voltage or a current supplied from the second buck converter to the LED, and controlling switching operations of both the first buck converter and the second buck converter on the basis of the detection result. <P>COPYRIGHT: (C)2013,JPO&INPIT |
