| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an LED drive circuit which is small in size and high in quality, capable of performing fade in and fade out operations of an LED used for a vehicle illumination and a signal lamp. <P>SOLUTION: Current supply from a first DC power source (battery) V1 to an LED lamp 103 is controlled by a switch means (MOSFET 1), and a voltage to be applied to a trigger terminal (gate) of the switch means (MOSFET 1) is raised or dropped with a prescribed gradient by a series circuit composed of a capacitor C1 and two zener diodes ZD1, ZD2 and a buffer circuit 102. Therefore, the voltage for the fade in and the fade out operations of the LED lamp 103 can be generated by a small capacitor without using a capacitor with a large capacity and the LED drive circuit can be downsized. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
