A memory attachment for oscilloscopes

The device described in this paper, called a "memnoscope," is a system for obtaining an oscillogram of random phenomena and events immediately preceding and following its occurrence. This system was developed and has been used to study arc-back phenomena m mercury-arc rectifiers. A description of the system is provided along with information on its construction and behavior. The memnoscope has proved its value in rectifier research. The opinion has been that arc-banks in rectifiers occurred only during transition time. Oscillograms obtained with the memnoscope show that arc-backs do occur at other times during the inverse cycle. Oscillograms have given information which has led to improved designs and to very substantial increases in the ratings of ignitrons.