Sealed ignitron principles extended to larger tubes

THE universal acceptance of the sealed ignitron for industrial power rectifiers up to 1,000 kw at 600 volts has raised the question as to the possibility of larger sealed ignitrons which would permit higher ratings for rectifier units. After considerable development, the same principles used for sealed ignitrons up to 400 amperes have been extended to larger sealed tubes with ratings up to 1,000 amperes at 250 volts d-c.