王从科 李   娜（中国中建设计集团有限公司，北京市 100037）

Selection of Power Amplifier and Line of Public Adress System

WANG Congke LI Na（China Construction Engineering Design Group Co.,Ltd.,Beijing 100037，China）

Abstract：In the passive terminal system of public adress,the relationship between the cross section,distance,attenuation of the line and the power of the loaded loudspeaker is calculated by the transmission line model,and several methods to solve the attenuation of the line are put forward. According to the total capacity of the load loudspeaker,the appropriate constant voltage power amplifier is selected.

Key words：public address system;power amplifier;transmission line attenuation;passive loudspeaker;voltage loss;constant voltage power transmission;maximum transmission distance;transmission voltage classes

摘　要：公共广播无源终端系统中，通过传输线路模型推算出线路的截面、距离、衰耗与负载扬声器功率的关系，提出解决线路衰耗的几种方法。根据负载扬声器总容量选择合适的定压式功率放大器。

关键词：公共广播系统；功率放大器；传输线路衰耗；无源扬声器；电压损失；定压式功率传输；最大传输距离；传输电压等级

中图分类号：TU852   　　　　   文献标识码：A

doi：10.3969 / j. issn.1003 － 8493.2021.04.009