这是一个红外报警系统，该系统通过555调制红个发光管，发出38KHZ的红外信号，对面使用一个红外接收头接收信号用来检测是否有人通过，如果有，则声光报警，-This is an infrared alarm system, which modulator 555 through a red light-emitting tube, issued 38KHZ IR signal, opposite to the first use of an infrared receiver to receive