简易烟雾警报器的设计1.(1)

.第I页简易气体烟雾报警电路设计摘要随着现代家庭用火，用电量正在逐年增加，家庭火灾发生的频率越来越高，在我国由于烟雾而引起来的火灾越来越多，人民每年因此而损失了大量的财产。据调查在最近发生火灾的大多数房屋都没有安装报警器。如果发生火灾之前就有警报系统预报现场的情况，从而避免火灾的发生，对人们将会有很大的意义。因此本文对烟雾警报器系统进行研究，是具有理论和实际双面意义的。本文讲述了简易气体烟雾报警电路，该报警器有降压整流与稳压电路，气敏传感元件和触发，报警音响电路等组成。其中气敏传感器原件使用于半导体气敏传感器QM-N5,QM-N5主要特点对液化气，天然气，城市煤气有较好的灵敏度，适用于家庭或工业上对液化气，天然气，煤气的监测装置。该装置电路简单，工作可靠，测量灵敏度较高，使用寿命长，成本低等优点。关键词：NE555，气敏传感器，报警.第II页TheDesignofSimpleGasSmokeAlarmCircuitAuthor:Adila.ailiTutor:LiHongxiaAbstractAlongwiththemodernfamilyusefireandtheelectricityconsumptionincreasesgradually,andthefamilyfiredisasterhigherfrequency,inourcountrybecauseofthesmogiscausedtomoreandmorefiredisaster,sotherearemanypeoplehavelostmanypropertyeachyear.Thesurveyshowsthatthemostofthefamilynotinstallthegassmogalarm,ifthegassmogalarmsystemitcanpredictionofthesituation,wecanavoidthefire,anditisverybeneficialtohumansafety.Sotheresearchofthegassmogalarmthathasthetheoryandtheactualtwosidedsignificance.Thisarticledescribesthesimplegassmogalarmcircuit,thisalarmshasthereductionvoltageandstabilivoltcircuit,gassensitivesensorandtriggeredandalarmsoundcircuitandsoon.AmongthemgassensorsusedinsemiconductorgassensorsQM-N5,QM-N5hasbettersensitivitytowardsliquefiedpetroleumgas,naturalgasindustry,citygas,andapplytohomeorindustrialtowardsliquefiedpetroleumgas,naturalgasindustry,gasmonitoringdevice.Thisdevicecircuitissimple,reliablework,longservicelifeandlowcostadvantage.Keywords:NE555,Gassensor,Alarm.第III页目录1绪论...........................................................................................................................................................11.1课题背景及目的..........................................................................................................11.2国内外研究的现状......................................................................................................11.3论文主要任务设计内容..............................................................................................22系统电路设计方案...............................................................................................................................33各单元电路设计....................................................................................................................................43.1电源电路设计............................................................................................................43.1.1电源变压器........................................................................................................53.1.2桥式整流............................................................................................................53.1.3滤波电路............................................................................................................73.1.4集成三端稳压器................................................................................................93.2气敏传感器...............................................................................................................103.2.1气敏传感器的分类..........................................................................................113.2.2气敏传感器的原理..........................................................................................113.2.3半导体气敏传感器..........................................................................................123.2.4QM-N5型气敏传感器..................................................................................133.3NE555简介...............................................................................................................143.3.1NE555的引脚图功能....................................................................................143.3.2NE555的工作原理........................................................................................153.4数据采集及处理电路设计.......................................................................................173.5报警电路...................................................................................................................173.5.1蜂鸣器简介....................................................................................................173.5.2蜂鸣器的结构原理........................................................................................183.5.3报警电路工作原理........................................................................................194整体电路设计......................................................................................................................................20.第IV页结论...........................................................................................................................................................21致谢...........................................................................................................................................................22参考文献....................................................................................................................................................23黄河科技学院毕业设计说明书第1页1绪论1.1课题背景及目的现代建筑的特点是楼层不断的加高，这主要是从缓解城市用地紧张的角度出发，同时还便于集中供电，供热，供气，便于集中控制和管理。现在不论是普通型（比如民用住宅）还是豪华型（比如高级宾馆）的高层建筑，都日益重视防火和安全技术的普及应用。因为其楼层多，人员密集，如果发生火灾，疏散困难，补救也困难，势必造成严重的人员伤亡