Overvoltage protection device e.g. for electronic measurement and control circuits - has circular or elliptical electrode eccentrically located inside another with plastic web in spark-gap

摘要

The protection device for shunting transient overvoltages has two cylindrical elements, preferably vertical, of which the inner circular element is eccentrically located inside an outer annular element. Between the elements, where they are closest, is a spark-gap. The inner electrode and outer electrodes may also be elliptical in cross-section. To aid the spark, there may be interposed in the gap a plastic web with low resistance to surface currents. There may be a third electrode surrounding the above two electrodes and this may accordingly be circular or elliptical. There may be a second plastic web between second and third electrode if eccentric and up to three webs between second and third electrodes if circular and concentric. ADVANTAGE - Improved arc extinction properties.