The Permatron — A magnetically controlled industrial tube

THE Permatron is a new gas-filled control tube in which the initiation of a discharge may be controlled by an externally applied magnetic field. The possibility of this type of control has been recognized during the past few years,¹ but little attention has been paid to proper design or to the interesting applications of tubes built specifically for magnetic control. The present paper has been written as the result of research work which has shown that magnetic-control tubes are a reliable and useful addition to the field of electronics. The trademark “Permatron” has been chosen to indicate the use of magnetic control.