本文以555定时器为核心，辅以基本RS触发器，设计了一套可以使用按键开关的双音报警电路，能够输出高、低音阶交替的报警音，并设有常亮和闪烁两种LED报警灯。该电路既可以作为独立的报警器，也可以稍作改动，作为一个复杂系统中的报警模块使用。采用multisim绘制-555 timer as the core, supplemented by basic RS flip-flop design can be set using the key switch, dual-tone alarm circuit can output high, low scale alternating alarm tone, and has two LED lit and flashing alarm lamp. The circuit either as a standalone alarm can also make a little change, as the alarm module in a complex system. Multisim draw