| 摘要 |
PURPOSE:To facilitate a reliable starting independently of the failure of a single starting means, by connecting a plurality of starting means for starting a passenger guard system, in series, to an electricity-passing means and providing on each starting means in parallel a by-pass means arranged to become electrically conductive upon electrical release of the starting means. CONSTITUTION:When a vehicle collision occurs and an acceleration detection switch SW2 is turned on, an electric current passes, from a battery B, through a reverseflow preventive diode D1 of an electricity-passing block 5, the acceleration detection switch SW2 thereof, an ignitor SQ1 and a constant voltage diode ZD1 of a starting block 3, and an ignitor SQ2 and a constant voltage diode ZD2 thereof in the order mentioned, whereby an ignitor agent is ignited by operations of the ignitors SQ1 and SQ2 to inflate the air bag. When it is now assumed that, at this time, the ignitor SQ1 has been electrically released in its interior, the voltage applied across the terminals of the constant voltage diode ZD1 rises up to a level higher than the breakdown voltage Vbd1 thereof to render the ZD1 electrically conductive. Since the current is thus allowed to flow with the ZD1 serving as a by-pass passageway, the ignition agent is ignited by operation of the ignitor SQ2. |
