Abstract: The present invention concerns a method for triggering certain high voltage electronic, gas discharge switches that are a novel type of high power thyratron. In this invention, triggering of switches of the so-called "pseudospark thyratron" type (a type of cold cathode thyratron) is enhanced by the inclusion of a very small, hot thermiionic trigger switch or cathode, separate and isolated from the main switch electrodes, to initiate the triggering discharge. The trigger cathode is protected from destruction by the main discharge current through the switch by mechanically and electrically isolating it from further participation in the discharge once the triggering process has been initiated.