Spark Quenching at Relay Contacts Interrupting D.C. Circuits

Quenching by resistors and by condensers in parallel with a switch having silver contacts is discussed, and a number of experiments are described which throw light on it. Explanations for the major phenomena in terms of the known properties of arc and glow discharges are offered which appear to be consistent with the experimental facts. The data and reasoning appear to be a sufficient basis from which to decide the approximate values of components needed to effect quenching in any given conditions within the range covered by the experiments.