H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
H01J1/02—Main electrodes
H01J1/13—Solid thermionic cathodes
H01J1/15—Cathodes heated directly by an electric current
Dispositif d'aide a la commutation de transistors de puissance, comportant un condensateur reservoir, et son application aux convertisseurs a transistors ou a thyristors