New methods of producing high-voltage square waveforms, and their application to spark photography

A review of chopping-circuit techniques used in the production of square waveforms is presented, and two new methods which have been developed for use up to 1 MV are described.The first of these consists of a 3-sphere gap circuit for chopping impulses with a scatter in the time of chopping of ±3%. Also a circuit employing an auxiliary impulse generator and trigatron sphere-gap has been used to produce square waves of predetermined duration, or for automatically removing the voltage shortly before collapse of the test-gap.This automatic technique is a valuable aid in the photographic study of discharge processes where the variation in time to breakdown is large.