带延时功能的微波自动报警系统的设计

Design of a Microwave Automatic Alarm with the Time Delay Function

设计了一个由微波发射器、555定时器、电压比较器和继电器组成的具有延时功能的自动报警器。该报警器由微波探头检测活动物体,将波动的电磁场信号转化为波动的电压信号后输出给电压比较器,电压比较器比较后的高电平触发555定时器工作,经过延时后的信号触发继电器报警。该报警系统克服了一般报警器容易出现的漏报警现象和其他微波报警器容易受外界电磁场的干扰所引起的误报警的缺点,很好地解决了报警系统的灵敏性与可靠性之间的矛盾。

The paper designs an automatic alarm with the time delay function which composed by the microwave launcher, 555 timers, the voltage comparator and the relay. This alarm equipment examines the active object by the microwave detector, then it will output the undulation voltage signal which is transformed from the undulate electromagnetic signal to the voltage comparatoro after the comparison of the voltage comparator, the output high level triggers 555 timers work, and output delayed signal to trigger relay reports to the police, The alarm equipment overcome the distorting alarm phenomenon which often exists in the common alarm apparatus and also avoids the failing alarm phenomenon caused hy the outside electromagnetic field disturbance. The contradiction between sensitivity and reliability of the alarm system is solved perfectly.