摘要 |
Apparatus for sensing the electrical conductivity of fluid wherein when electrodes of the apparatus are exposed to fluid a voltage is developed on a capacitor which voltage has a magnitude determined by the condition of the electrical conductivity of the fluid to which the electrodes are exposed. A portion of the developed voltage is obtained, such as by means of a voltage divider connected across the capacitor, and this voltage portion is compared by means of a voltage comparator to a reference voltage. When the comparison indicates a predetermined relationship, for example equality, between the developed voltage portion and the reference voltage, a signal is produced which can be utilized to operate a load. In particular, the signal can operate a semiconductor controlled rectifier to complete a discharge path from the capacitor to the load. The load can be an electro explosive device included in a release mechanism for uncoupling a parachute canopy from its load upon landing in water. The load is connected in a series loop including the electrodes, voltage divider and a voltage source with the result that the electrical integrity of the load can be tested using standard equipment and procedures. |