An electronically controlled PAX ¿ Its design and performance

RESEARCH IN JAPAN on electronic telephone switching techniques has made remarkable progress since the close of World War II. Among numerous trial models built are the ¿-type electronic switching system developed at Electrical Communication Laboratories of Nippon Telegraph and Telephone Public Corporation, announced in December 1955,1¿3 and the parametron-type semielectronic switching system, publicized in December 1956 by two of the authors of this paper. Developmental research has continued on the latter system as well as on electronic devices to be used in this field.