解决电话控制问题的方法探讨

A Discussion on Solution of Telephone Control

该文对电话计费控制问题进行了探讨，介绍了一种话机外接硬件控制系统，用来防止长途受限用户非法拨打长途电话，并对授权用户显示和记录被叫号码及通话时长。该文还描述了系统的总体框图、电路原理、设计原则及实现方法。

This paper discussed a solution to telephone control.It presents a hardware control system externally connected to the telephone set to prevent the long distance call made by facility restricted user.The system can recognize the user identity,display and record the called telephone directory number and the duration of conversation.Besides,the system architecture,principle of circuit design and its implementation are also presented in detail.