文档介绍：摘要家庭使用液化气、燃气等可燃气体作燃料的越来越多,但是这些气体有害、易爆炸,隐患事故多,如气体泄漏时不能及时发现和处理,会给家庭及邻居带来灾难性危害。本次设计内容包括可燃气体报警电路的结构及其工作原理。此报警电路以气敏半导体传感器为主要组成部分,气敏半导体传感器检测到可燃气体时通过电导率的改变来控制多谐振荡器及正反馈振荡器间歇工作,通过报警电路从而达到报警的目的。随着石油化工行业的发展,易燃、易爆气体的种类和使用范围都随之增加。这些气体在使用过程中一旦发生泄漏,与空气混合后将会引发火灾。由于气体本身存在的扩散性,发生泄漏之后,在外部风力作用下,可燃气体会沿地表面迅速扩散,扩大危害区域。一旦发生可燃气体泄漏事故,及时可靠地探测空气中可燃气体的含量,及时采取有效措施进行补救,采取正确的处置方法,减少泄漏引发的事故,是避免造成重大财产和人员伤亡的必要条件。该报警器以 AT89C51 单片机为核心,采用高精度敏感元件 MC112 ,测量***浓度值,采用 AD623 新型集成运算放大器、ICL7109 模数转换器,是一种电路设计新颖、参数测量准确、结构简单、成本低、控制能力强、操作方便的***浓度报警器。该报警器具有以下特点:测量范围宽、精度高、可检测的***浓度为 % ~ % ;具有设定报警下限值和声、光报警功能;仪器输出为低功耗,工作电压稳定等优点。关键词:可燃气;单片机;报警器;浓度 Abstract Family use liquefied petroleum gas, such as fuel gas of flammable gas, but the more harmful gases, explosive, hidden accidents, such as gas leak cannot find and deal with family and neighbors, catastrophic damage. This design content including flammable gas alarm circuit structure and work principle. This alarm circuit with gas sensor as the ponent of semiconductor, gas sensors detect flammable gas semiconductor when the change control by conductivity more harmonic oscillator and the positive feedback oscillator, through the alarming circuit intermittent and alarm. With the development of petrochemical industry, flammable, explosive gas type and scope of use are increased. These gases in the course of the event ofa leak, and air mixture will cause a fire. As the gas diffusion inherent nature of the leak, the effect of external wind, gas experience can spread rapidly along the surface, expanding hazard area. Once bustible gas leakage accident occurred, timely and reliable detection bustible gases in air content, in time to take effective measures to remedy, to take the correct disposal methods to reduce the leakage caused by accident, is to avoid a major property and casualty essential. This alarm with AT89C51, MQ-412 ponents with high precision measuring gas density, use, TL062 new integrated operational amplifier, ADC0809 , isa kind of circuit design is novel,