A double-input laboratory oscilloscope

THE ELECTRICAL engineering student engaged in a study of a-c theory is helped immensely in gaining a basic understanding of the interrelationships between the voltage and current quantities in a circuit when he is able to observe and study at least two of the quantities simultaneously. However, commercial apparatus which makes this possible, the oscillograph, the cathode-ray tube oscilloscope with “electronic-switches,” and double-beam cathode-ray tube oscilloscopes, have been little used by the student himself because the problems of interconnections, time-base adjustments, synchronizing, calibration adjustments, and the like are beyond the abilities of the average student commencing his study of a-c circuits.