Two forms of electronic switch

The basic principles of electronic switching are discussed, two main classes being established: (a) that using a switching frequency not related to the work frequency, and (b) that using a locked switching frequency. Typical circuits that have been found satisfactory are given with circuit constants. Representative oscillograms are reproduced. The limitations of the two types are stated as a guide to the selection of the correct type for a specific function. Two oscillograms are given which show the application of an electronic switch to investigations of X-ray equipment.