| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a driving device and an illuminating device which reduces a power loss in a constant current element for supplying a specified current to LEDs. <P>SOLUTION: In the driving device, one end of each of resistance elements R1, R2, R3, and R4 is connected to a cathode of each of LEDs 1-4, and the other end of each of resistance elements R1, R2, R3, and R4 is connected with a microcomputer 50. The microcomputer 50 detects voltage of the cathode of each of the LEDs 1-4 by means of the resistance elements R1-R4. The microcomputer 50 also controls a regulator 20 depending on a difference between a detected voltage and a specified threshold, and reduces voltage Vdd. Thus, emitter-collector voltage of a transistor Q1 is reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
