| 摘要 |
<p>An electric circuit for measuring impedance using transient techniques. Traditional methods of measuring small impedances apply a DC current through the device and measure the voltage potential induced across it. If the device is an explosive, the heating effect from testing with DC current causes the failure mechanisms of accelerated explosive aging, accelerated dissimilar element migration in bridgewire alloys, and bridgewire movement until separation from its bonding posts from dissimilar coefficients of thermal expansion and contraction. The application discloses a diagnostic circuit and triggering circuit using impulse testing which monitors firing readiness of an explosive without inducing thermal effect degradation and without requiring its removal from deployed service. Uses of the invention include apparatus for measuring a low impedance without using large DC currents and for monitoring the condition of explosives, propellants and associated firing devices which exhibit an impedance that can be characterized as to the extent of degradation from aging or damage, thereby indicating their readiness. Automotive air bag systems, pyrotechnic cutters, rocket motors, aerospace vehicle systems, weapons and ordonance which use such explosives, propellants and/or firing devices are a partial list of impedance monitoring applications for the invention.</p> |
