| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an LED drive device, a lighting system and a luminaire having a compact, inexpensive and simple configuration capable of reducing the thermal stress in an LED element and consistently irradiating light. <P>SOLUTION: An LED drive circuit 2 comprising a DC power source 1, an LED drive circuit 2, and an LED unit 3 consisting of a plurality of LED elements La connected in series performs the shifting operation to the output characteristic with the output power reduced if the detected value of the LED voltage Vf is reduced, reduces both the output voltage V2 and the LED current IL, and suppresses the heat generation of the LED element La. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
