Superposition applied to mechanical rectifier contacts

CONTACTS of mechanical rectifiers physically make and break connections between the a-c phase terminals and d-c terminals of the rectifier, but do not contribute to the important phenomena of commutation. Commutating reactors in series with the contacts are used to produce the required conditions during ¿make¿ and ¿break¿ steps in which the contacts are able to perform their limited functions. The main power circuits may be seen in heavy lines in Fig. 1. Make and break phenomena are equally important, but this paper deals only with break problems, the make problems having been adequately solved in modern rectifiers.