本文介绍用一片音乐及可控硅组成的断线报警器。电路如附图,当检测线未碰断时,可控硅的控制极无电压,可控硅不导通,音乐片没有电压而不工作;当线碰断后,可控硅导通,音乐片得电工作,喇叭发出报警声,此时即使把断线接上,喇叭 This article describes the composition of a piece of music and SCR break alarm. Circuit as the photo, when the detection line is not touched off, the SCR control voltage, SCR does not conduct, the music does not work without voltage; when the line is broken, the SCR conduction, music Electrical work, horn alarm sound, this time even if the disconnect connected, speakers