摘要
在各类电话计费及管理系统中，由于有的交换局没有反极性信号，因而对用户电话的计费与管理无法实现实时控制。文中介绍一种科学、实用、可靠的信令接收与解调电路。此电路不但可产生模拟反极性信号，而且可抑制语音干扰和线路噪声。
Among various kinds of telephone charging and administation systems,real time control cannot be realized in some exchanges due to the absence of polarity reversing signal.In this paper,a scientific,practical and reliable signal receiving and demodulation circuit is presented.This circuit can not only produce analogous polarity reversing signal,but also suppress disturbance and circuit noice,thus solving the problem of real time charging and administrating effectively.
出处
《电子科技》
1997年第2期31-34,共4页
Electronic Science and Technology
关键词
反极性信号
实时计费
电路设计
电话
polarity reversing signal,real time charging,circuit design
