| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To effectively absorb a surge voltage generated by a load dump surge in a power line with low-cost circuit configuration without adopting a high-power Zener diode for absorbing the surge voltage to thereby prevent influence on an electronic device connected to a power line and a light source element. <P>SOLUTION: In a vehicular lighting fixture flashing a light source element connected between a power line supplying power of a power source and a ground line, a semiconductor element in charge of supplying and blocking the power to the light source element is inserted in the power line, and an overvoltage protection circuit is formed which: has a surge protective resistor connected in parallel to a feed line of the semiconductor element; is further provided with a surge voltage detection means between the power line and the ground line; and when the surge voltage detection means detects a surge voltage generated in the power line, stops operation of the semiconductor element to block the power supply and also absorb the surge voltage by the surge protection resistor. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
