Active transient suppression apparatus for potentially explosive environments

Abstract

Active transient suppression apparatus coupleable in series with an electrical pathway into a potentially explosive environment for limiting current, voltage and energy thereto comprises: an impedance element coupleable in series with the electrical pathway; a protection circuit comprising: at least one semiconductor element including a current conduction channel in series with the impedance element in the electrical pathway; and a driver circuit operative in response to a drive signal to switch the at least one semiconductor element to a non-conducting state; and a sense circuit coupled to the impedance element for sensing current conducted therethrough and generating a signal proportionally representative of the sensed current, the generated signal becoming the drive signal as it reaches a threshold level. The active transient suppression apparatus may be embodied in a system for determining a quantity of fuel in a container. The system comprises: at least one sensor disposed at the container; sensor excitation system coupled to each of the at least one sensor through an electrical pathway for providing an excitation signal thereto; and the active transient suppression apparatus disposed in series with each electrical pathway.