摘要
本文研究了用市电线路传输低频报警信号的接口装置——分离滤波器 .该滤波器能滤掉 2 2 0伏的工频信号 ,而让低频信号通过 ,获得了实用新型专利 .
The interface device (separative filter)to transmit an alarm low frenquency signal through an urban transmission line is studied in this paper.This filter can filtrate 220 volt power frenquency signal and make a low frenquency signal pass throngh.Thus,it has been awarded“New Type Practical Patent Certificate”.
