Some Small Direct Current Sets

The construction of a commercial Chaffee gap (copper and aluminum electrodes in hydrogen) is described. The use of such gaps in connection with "starting" and "tone" circuits for the production of sustained waves modified into groups of audio frequency is considered. The phenomena are illustrated by Braun tube oscillograms. Impulse excitation is obtained. The construction and operation of a ¼-kilowatt panel set and a ⅙-kilowatt aeroplane set of this type are given in detail, together with performance data.