上下限越限声光报警电路设计.docx

学校代码： 10128学 号： 201220302029课程设计说明书（题 目：高、低限越限声光报警器电路设计学生姓名： 孙 振 山学 院： 机械学院班 级： 测控12-2指导教师： 徐永祥 徐刚2015年7月15日摘要声光报警电路被广泛用于生活和工作当中，用发光和发声等信号来提醒人们。温度报警电路中温度检测是重要的一环。将现场温度控制在一定范围内，是在各种实际应用的重要保证和前提。因此温度检测系统在工业控制领域中十分重要。本论文主要是针对被测量是温度的高低限越限声光报警设计。电路主要由检测电路，放大电路、比较电路、报警电路三部分构成，论文分别针对每一部分的电路进行了展开设计。检测电路采用热敏电阻接在电桥放大电路中，将输出送入到电压比较电路中，电压比较电路采用的是窗口电路。电桥电路的输入值和比较电路的阈值进行比较，如果不在设定的阈值范围内，将会输出高电平触发报警电路，报警电路由555定时器和扬声器、二极管构成。得到高电平信号后扬声器会发出一定频率的声音，二极管会被点亮实现声光报警。此系统的设计可应用于仓库测温、楼宇空调控制和生产过程监控等领域，将来也可以渗入到人们工作和生活的各个角落，有力地推动各行业的技术改造和产品的更新换代，相信会有较好的应用前景。 关键字：热敏电阻；越限报警；温度检测；声光报警 Abstract The alarm circuit is widely used in our daily life and work, reminding people with the light and sound signals. Temperature detection is an important part in temperature alarm circuit. Keeping the temperature on spot in a certain range is a key guarantee and premise of various practical applications. Therefore, temperature control system is very important in industrial controlling area.This thesis is mainly aimed at the measurement of the high and low limit of the temperature of the sound and light alarm design. The alarm circuit is made by the detection circuit, the amplifying circuit, the comparison circuit and the alarm circuit. We design each part of the circuit in detail. The detection circuit contacts the thermistor in the electric bridge amplifying circuit and the output is fed into the voltage comparator circuit, which used the window circuit. The input value of the bridge circuit is compared with the threshold of the comparison circuit. If it is out of the threshold range, the high level trigger will be output to the alarm circuit, which is composed of 555 timer and speaker and diode. High level signal is obtained after the speaker will emit a certain frequency of sound, the diode will be lit to achieve sound and light alarm finally.This system can be applied to the storage temperature measurement, air-conditioning control in buildings, and production process monitoring, and other areas. I