Discharge Processes in a Low-Voltage Microgap Surge Absorber

Discharge processes in the newly developed microgap surge absorber (MSA) are studied using a photomultiplier and image converter camera. The MSA is for the protection of low-voltage circuits from overvoltage surges and consists of a semiconducting thin film coated on a ceramic tube with microgaps which are made by removing annular rings in the coated film by a laser beam. The highly desirable characteristics of the MSA as a surge absorber result from the microgap which supplies initial electrons and triggers a surface streamer to build up a glow discharge.