| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress the power consumption of a semiconductor switch in a drive circuit of a semiconductor light source. <P>SOLUTION: A switch drive circuit 8 controls a semiconductor switch 4 into an off-state when a control signal Vc is at an L-level. The switch drive circuit controls the semiconductor switch 4 into an on-state when the control signal Vc is at an H-level. A current control circuit 9 controls a constant current power supply 100 in such a manner that the constant current power supply 100 passes the drive current of 30 A to an LED 3 when the control signal Vc is at the L-level. The current control circuit controls the constant current power supply in such a manner that the constant current power supply 100 outputs the drive current of 10 A when the control signal Vc is at the H-level by the level-setting of the current setting voltage Vref. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
