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.