气体传感器电路设计.doc

多功能汽车防护报警系统的研究与制作 摘要 随着科技发展，汽车的使用量越来越大。汽车环境对电子产品而言是非常苛刻的 本论文就是为了针对这两种情况而提出一个防护报警系统的设计方案。 本论文对气体报警以及水位检测报警电路的设计进行了深入的研究，比较合理地选择了系统的设计方案，并对系统的设计和各个组成部分进行了详细的分析和介绍。本系统由气体信号采集电路、水位检测及电源控制电路和单片机控制电路三大部分构成。气体报警部分通过气体传感器电路获取信号，通过A/D转换把数据送给单片机。单片机通过对数据进行处理、判断，从而对排气扇以及声音报警电路进行控制。水位检测及电源控制部分则通过检测水面是否达到特定的高度，当水面达到特定高度时给单片机发出信号。当单片机获得信号时控制继电器断开电源与电路的连接，减少水浸对电路的损坏。在程序设计上采用时间片轮转调度算法，提高程序运行的效率。 关键词：可燃性气体、水位、单片机、传感器 The Research and Production of the Multifunctional Protective Alarming System in Cars Abstract With the development of technology， the use of cars is increasing. Yet， the using environment of cars has a high requirement towards electronic products. When cars stay in the bottomland， the circuit in cars may be threatened by waterlog due to rainstorm or other reasons. In this case， if accumulators continue to provide electricity for the circuit， short circuit may happen. Besides， the windows of cars are great airproof. If the driver enjoys air condition in the stopping car， the air is hard to flow in and out of the car and thus the CO ejected by the engine will gather in the car， which will make the driver poisoned and even lose his life. This thesis provides a project of protective alarming system design for the above two situations. It deeply studies the design of air alarm and water level inspecting circuit， and selects a proper design project. Furthermore， it offers a detailed analysis and introduction of this design. This thesis consists of three parts: the collection of air signal， water level inspection and power and MCU control. In this thesis， it discusses how to obtain signals through sensors. This system sends the data to the MCU by the A/D conversion. The MCU analyzes the data and thus control the exhausting fan and alarm circuit. The water level inspection and power control examine whether water comes to a certain level. If water comes to a certain level， this system sends a signal to MCU. Receiving the signal， the MCU controls the relay to cut off