Gas filled lightening arrestor for telephone lines - has two cupped electrodes of low work function metal separated by annular insulator

摘要

The overvoltage limiters for use in telephone lines comprises a gas filled cell providing low cost protection against any overvoltage appearing on the lines and particularly against lightening strikes. The approximately symmetrical cylindrical cell uses low work function material for electrodes obviating the need for a radioactive 'keep alive' source up to five electrons may be employed.