1、外文原文 Based on infrared alarm technology security systems 1 the introduction 1.1 the research significance of this topic research situation at home and abroad . With the development of society and science and technology unceasing development, peoples living standards been improved greatly, and to the
2、 private property protection means in the unceasing enhancement, the intelligent facilities for anti-theft puts forward new requirements. This design is to meet the need of modern residential anti-theft designed family electronic alarm system. It in previous devices based on improved greatly, becaus
3、e use the single-chip processor signal, not only can used for single residential area, also can be used in a large-scale residential security systems. Its the job of the performance is good, do not appear to report and misstatement phenomenon, safe and reliable. In our country, the present market co
4、ndition alarm basically has triggered alarm system pressure switch electron and alarm system and pressure shading triggered alarm system, etc. Various kinds of alarm, but this several common alarm there are some shortcomings. This system USES a human pyroelectric infrared sensor in the human body de
5、tector in the flied, passive pyroelectric infrared detectors because of its low cost, easy fabrication, low cost, installation is more convenient, anti-theft performance is stable and high sensitivity, safe and reliable, has attracted broad family characteristics such as popular with the customers.
6、And alarms installation concealment, not easily by rogue found. 1.2 infrared alarm technology introduction 1.2.1 nature objects of the infrared radiation The nature of any object, as long as the temperature above absolute zero (273 ), constantly outward issued infrared radiation, and travel at the s
7、peed of light energy. Object radiate outward infrared radiation of energy and the object of temperature and infrared radiant wavelength. Assuming objects launching infrared radiation of peak wavelength for a few, its temperature for T, the radiation energy equals infrared radiation of peak wavelengt
8、h gerben and object product temperature T. This product is a constant, namely: The higher the temperature of the objects, emit infrared radiation of the smaller peak wavelength, send out infrared radiation energy is bigger also. 1.2.2.pyroelectric effect Passive infrared detector also called pyroele
9、ctric infrared detector, its main working principle is pyroelectric effect. Pyroelectric effect means if make some strong dielectric material (such as qin batio3, qin wrong acid lead P (zT), etc.) of the surface temperature changes, then with the temperature rise or fall, material surface occurs pol
10、arization, namely on the surface of the charge will be produced change, and material surface charge lost balance and eventually charge will change withvoltage or current form output. 1.2.3 pyroelectric infrared sensor basic structure Pyroelectric infrared sensors from sensor detection yuan, interfer
11、ence filters and mosfet verifier three parts. According to the number of detecting yuan to points, pyroelectric infrared sensors have unit, double yuanhe four yuan to wait for a few kinds, for human detection of infrared sensor adopts double yuan or four yuan type structure. According to pyroelectri
12、c infrared sensor utility cent, have the following kinds: used for measuring temperature sensor, its the job of the wavelength of (1-20) nano, Used for flame detection sensor, its the job of the wavelength for 0.435 + / - 0.15 nano, For human detection sensor, its the job of the wavelength of 7 to 1
13、5 feet. Figure 1.2 is a double detection yuan pyroelectric infrared sensor structure schematic drawing. The sensor will two opposite polarity, special 1.2.4 pyroelectric infrared detector basic principle Pyroelectric infrared sensor by receiving mobile human radiation that certain wavelengths of inf
14、rared radiation, can be transformed into and human body movement speed and distance, the direction of low-frequency signals about. When pyroelectric infrared sensor by ir radiation sources of radiation, its internal sensitive materials temperatures will rise, polarization intensity is abate, surface
15、 charge reduce, usually will release this part of the charge called pyroelectric charge. Because of pyroelectric charge how many can reflect material changes of temperature, so by pyroelectric charge by circuit transformed into the output voltage can also reflect material changes in temperature, thu
16、s detect ir radiation energy changes. 2 hardware system design 2.1 infrared anti-theft alarm system hardware design Because this design focuses on family guard against theft, real-time monitoring of a narrower range, so this design by simply using a passive infrared detector is enough. Therefore, in
17、frared intelligent anti-theft alarm system, and the specific design requirements for: (1)completes to high sensitive infrared sensor design, make its can warning of what happened real-time and accurate detection. (2) automatic alarm (automatic dial-up alarm audible and visual alarm). We design the s
18、ystem must have the following function module: 1.passive infrared detector, 2.sound-light alarm, 3.telephone automatic dial-up function； 4.continued uninterrupted power supply, According to the system to complete functions, we adopt single chip microcomputer as the core of the system unit, electroni
19、c detection, intelligent control and telephone tong 2.2 telephone automatic dial-up alarm circuit design In order to simplify the whole system design process, we do not adopt MT880 chip dialing. Realization process is as follows: First in telephone storage inside put on domestic host cell phone numb
20、er or alarm call 110. From MCU pins p2.0 and p2.1 drawn two wiring connect relays, a pick telephone keyboard MianDiJian, another connect telephone keyboard keys, automatic weighing dial because the phone keypad scanning is similar microcontroller keypad scanning, so can make SCM give fitst p2.0 a signal, lets telephone h-f, then give the p2.1 a signal, let relay connected, automatic weighing dial the key a potential, let telephone automatic dial-up, so they could finish the system alarm function. 2.3 system working principle
