| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device in which a high voltage side control power source is generated certainly in a simple and economical structure even if a switching element is connected to a positive potential side of a DC power source. SOLUTION: In the lighting device provided with a control power source part 5 to supply a control power source Vcc to a control part 4 which outputs a driving signal for switching on/off a switching element Q1 of a step-down chopper part 2, the switching element Q1 is connected with a positive potential side of an output end of a DC power source part 1 and an electric light source 3 lit by DC is connected with a zero potential side of the output end of the DC power source part 1, and a capacitor C2 for a control power source for generating a driving signal of the switching element Q1 is charged from the control power source part 5 when the switching element Q1 is off, and an impedance element R1 having an resistance component is connected to a passage supplying DC power to an electric light source 3 from the positive potential side of the output end of the DC power source part 1, and the control part 4 has a delay means to output a driving signal for putting on/off the switching element Q1 at a prescribed time after the control power source Vcc is supplied. COPYRIGHT: (C)2011,JPO&INPIT |
