| 摘要 |
<p>The telephone apparatus has a central unit connected with a central switching system through one or more trunk lines, and each has an entry point to subscribers by means of local lines. The system is made up of modular units, comprising a logical transmitter, anda unit incorporating an MOS sender-transmitter, pulse generator and line driver. The transmission section includes a micro-telephone and a current circuit loop. Adjacent to one another are the central circuit box (CCB) and the trunk circuit controller (TCC). For each specified trunk line is provided a time signal input generator, a current feed and voltage injector and a battery power supply source.</p> |
