Automatic fire alarm systemThe traditional electron safe alarm system mainly is through the sensor automatic detection, produces the alarm, sends out the alarm the scene or reports to the police through the special electric near distance, thus causes peoples vigilance. Through many years research and the development, the present alarm apparatus may say is the class is multitudinous. As a result of the alarm apparatchik development and the social each domain anxious need, can application domain be more and more many, specially is overdevelops in the civil domain. In recent years, the infrared alarm apparatus already became reports to the police a domain hot spot,because it used was not the obviously infrared acquisition, Hereford the hiding to be good, characteristic and so on security. Infrared sensor is different according to the mechanism may divide into the light survey and the hot survey. The light acquisition sensor is uses the photon effect the acquisition aid. This kind of sensor speed of response quick, sensitive high, the examination characteristic is good, but needs cool, uses not conveniently. Moreover the component examination sensitivity and the infrared wave length concern. The hot acquisition is uses hotly releases the electricity effect the acquisition aid. After receives the goal the infrared misinterpretation increment, the temperature elevates causes the censorial certain physical quantities changes, through examination physical quantity change definite infrared emission. This kind of sensor works under the room temperature condition, examination sensitivity also very high, speed of response also very quick,moreover has nothing to do with with the infrared emission wavelength, may survey the power only to receive the background irradiation limit, the application is very convenient. This article designs atheist passive form hotly releases the electricity infrared acquisition aid. In the article mainly elaborated has hotly released electrician the principle, hotly releases content and so on Malayalam circuit which the electric detector the characteristic,the BISSAU signal processor, 555 timers composed. Finally designed completes has hotly released the electricity infrared detection alarm apparatus the hardware electric circuit. With the modern family use of fire, electricity consumption increases, the frequency of home fires is getting higher and higher. The family of fire, it is easy to fight does not occur promptly, the lack of fire-fighting equipment and the presence of panic-stricken people, to escape unfavorable factors, such as retardation, which eventually led to a significant loss of life and property. Explore the characteristics of the family of fire and fire prevention measures. For the prevention of domestic fires, reducing the fire losses have practical significance. In the modern urban family, because of lot of people do not understand common sense home security caused by fire, so that the happy family Geog underlined blink of an eye, and some lead to destruction, but the event of household fires, improper disposal, alarm delay is caused so that people should get to know more about the main causes of household fires, master to prevent the fire of knowledge and in case of fire to protect his or her own way, timely elimination of The United Kingdom each year more than 50000 families of serious fires, most of them fire casualties and significant loss of household assets, and some result in the neighbors, more heavy fire losses. Investigate the causes of fire in time, the vast majority of home fires happen parties said that the fire always feel that things are other people with their own far away, did not think this will happen even in the top of his head. Home fires are the main reason for negligent not to take timely preventive measures .In some of our large and medium-sized cities, almost every day family fires, fire prevention is so each family must always pay attention to. If your home based on the actual situation in advance to take simple fire prevention measures, a number of tragedies are entirely avoidable. Automaticfirealarmsystemisinordertoinformtheearlydetectionoffire,andtakeeffectivemeasurestocontrolandfightfires,andsetinabuildingorotherplaceofanautomaticfirefacilities,isthatpeoplewithapowerfultooltofightthefire.Firealarmsystem,firedetectorsgenerally,regionalcentralizedalarmalarmandcomposition;alsoberequiredundertheprojectwithvariousfire-fightingfacilitiesandcommunicationdeviceslinkedtoformacentralcontrolsystem.Fromautomaticalarm,automaticfirefighting,evacuationguidance,systemprocessshowsthat,fireupacompletefilemanagement,firecontrolsystem.Firedetectorsarefiredetectiondevices,asinthestageoffirewillproducesmokewithhightemperatureflamecells.Thesmoke,heatandlightintoelectricalsignalsthroughthedetectoralarmor