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(一)简史电话发明于1875年.随着电话的实用,为了使许多电话用户能够彼此通话,需要一个转接中心,管理用户话机的接线和拆线工作.这种转接中心就是交换机.电话交换机已有近百年的历史,如同其它许多工业生产与交通运输设备一样,经历了人工和自动化两个阶段.自动交换方式长期以来使用的是各种机电式设备.随着电子技术的迅速发展,近年来正在向电子化过渡.现在存贮程序控制的电子电话交换机开始进入使用阶段,成为当前的主要发展方向.
(A) a brief history of the phone was invented in 1875. With the practical phone, in order for many phone users to talk to each other, you need a switching center to manage the user’s phone wiring and stitching work.This switching center is the switchboard. Telephone exchange has nearly a hundred years of history, as many other industrial production and transportation equipment, has gone through two stages of human and automation.Automatic exchange has long been the use of a variety of mechanical and electrical equipment.With the rapid development of electronic technology , In recent years is the transition to the electronic and now stored-program-controlled electronic and telephone switches into the use phase, the current main direction of development.