| 摘要 |
<p>An air bag firing circuit (50) comprises a firing path (53) which includes redundant acceleration sensors (52), i.e., two sensors of like threshold connected in parallel. Each sensor comprises normally-open switch means (80) operated by an inertial mass and shunted by a resistor (82). A battery (60) maintains a known voltage across the firing path (58) while a microprocessor (86) checks the integrity of the firing path by periodically reading and comparing the voltages achieved at various points thereabout. The microprocessor further tests each sensor individually by electromagnetically biasing the sensor's inertial mass in a manner so as to close the switch means thereof while determining the effect of such testing on the voltages achieved about the firing path. Upon the detection of a sensor failure, the microprocessor electromagnetically biases the sensor's inertial mass in a manner so as to maintain the switch means thereof in its open position, whereby the malfunctioning sensor is functionally removed from the firing path without impairing the function of the other sensor connected in parallel therewith. <IMAGE></p> |
