| 摘要 |
<p>A circuit for control of a device triggerable by a direct current e.g. an explosive ignition charge, is designed to incorporate customary safety features with reduced complexity and hence cost. The ignition device contains a means of suppression of explosive material as well as the ignition charge. In the non-triggered condition a d.c. flows in both conductors of a twin conductor cable which is monitored for short or open circuit faults. A zener diode (52) in series with the trigerring element (10) has a zener voltage greater than the series current supply voltage which can be switched to a voltage greater than the zener voltage by means of a switch (20) and voltage source (16) under control of automatic detectors (60) of danger conditions.</p> |
