| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an LED lighting device of power source separate installation type having an LED unit 2 and a power unit 1 separately installed, an LED being not broken even when a noise voltage (ground noise voltage) of common mode is superposed on an AC power source AC to which the power unit 1 is connected. <P>SOLUTION: The LED lighting device supplies the LED unit 2 with a DC current through a pair of power lines 3a, 3b from the power unit 1 having a rectifying circuit DB and a DC-DC converter 5 stored in a metallic case 6, and includes a capacitor C5 for ground noise voltage bypassing which connects a secondary-side ground G2 of the DC-DC converter circuit 5 to the metallic case 6 and also provided with a ground line 7 which connects the metallic case 6 and a conduction portion 4 of a LED unit 2 to each other. The capacitor C5 includes its electrostatic capacitance set to be larger than the composite stray capacitance Cy between respective LEDs and the conduction portion 4 of the LED unit 2. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
