Abstract: The protection of potentially incendiary circuits is achieved by a power system which comprises a power supply connected by power distribution wiring to one or more modules, the one or more modules each comprising an intrinsically safe circuit including a load, a sensor to detect the voltage supplied to the load, and a fast-acting switch arranged, in response to the detection of a decrease in the supplied voltage, to disconnect the load in such manner as to prevent any series break upstream from the switch from becoming incendiary.

Abstract: An electrical safety barrier for use as a protective device between a hazardous area and a non-hazardous area has a substrate of ceramic material which carries thick film printed resistors and other surface mounted safety components, such as Zener diodes. By using such hybrid circuit technology one can achieve a very slim barrier, reduce the number of soldered connections usually required, and obtain high power density due to the high thermal conductivity of the ceramic. The ceramic substrate is encapsulated within a housing which includes a ground shoe assembly to enable the barrier to be mounted on a rail.

Abstract: A method for illuminating explosive, flammable, and other hazardous environments. The method employs electroluminescent lights heaving controlled dielectric strength and capacitance, which when matched with the low current and voltage from an intrinsically safe power supply, and the controlled capacitance of each lighting circuit, produces an emergency lighting system which is both safe and effective.