【正文】 ity. Measured the volume of small changes in signal will be converted to electrical signals. Chemical sensors, including those by chemical adsorption, electrochemical reaction, such as the situation for the causal relationship between sensors, the measured signal small changes in volume will also be converted into electrical signals. Some sensors can not divided into the physical category, it should not be divided into chemical categories. Most of the sensor is based on basic physical principles for the operation. Chemical sensor technology more questions, such as reliability issues, the possibility of mass production, prices etc., and have solved these problems, the application of chemical sensors will have Common sensor applications and operating principle are presented in Table . In accordance with its purposes, the sensor can be classified as: Stress sensitivity and the force sensor position sensor Level sensor energy sensor Speed Sensor thermistor sensor Acceleration sensorray radiation sensor Vibration sensor humidity sensor Magic Sensor Gas Sensor Vacuum sensors biosensorset Its output signal as the standard sensors can be divided into: Analog sensors will be measuring the volume of nonelectrical converted into analog signals. sensor will be measured nonelectrical quantity into a digital output signal (both direct and indirect conversion). Ying digital sensor will be measuring the amount of signal into frequency signals, or shortcycle signal output (including direct or indirect conversion). Switch sensor When a measurement signal to achieve a specific threshold, the sensor output corresponding to a specified low or high signal. 哈爾濱理工大學遠東學院學士學位論文 19 At the role of external factors, all materials will be made accordingly, with a characteristic response. Them the role of those outside the most sensitive material, that is, those with functional properties of the material, was used to produce a sensor sensitive ponents. Materials from the application point of view of the sensor can be divided into the following categories: (1) in accordance with the category of Materials according to the physical properties of materials at (2) conductor insulator semiconductor magic (3) The crystal structure of subMaterials Single crystal polycrystalline Amorphous Materials ： With the use of new materials is closely related to the development of the sensor can be summed up in the following three directions: (1) at a known material to explore new phenomena, effects and response, and then enable them to be at sensor technology actually used. (2) to explore new materials, application of those known phenomenon, effects and response to improve the sensor technology. (3) at the basic research on new materials to explore new phenomena and new effects and reactions, and in sensor technology to be the specific implementation. Modern sensor manufacturing progress depends on sensor technology for new materials and sensitive ponents of the development of strength. The basic trend of the sensor development are dielectric materials and semiconductor applications, as well as closely related. Table can be used to give a number of sensor technology, be able to convert energy forms of material. ： In accordance with its manufacturing process, the sensor can be divided into: Integrated thinfilm sensor sensors ceramic thickfilm sensor sensor Integrated sensors are produced using standard siliconbased technology of semiconductor integrated circuits manufactured. Will also be used for the initial treatment is usually measured part of the signal circuit is also integrated in the same chip. Thinfilm sensor is deposited on dielectric substrates through (substrate) on the corresponding sensitive material film formed. The use of hybrid technology, the same part of the circuit can be manufactured on this substrate. Thickfilm sensor is the use of the corresponding material slurry, coating on the ceramic substrate made of, the substrate is usually made of Al2O3, and then heattreated, so that thickfilm forming. Ceramic sensors using standard ceramic technology, or some variant of process (sol gel, etc.) production. Completed the appropriate preparatory actions, have been forming ponents at high temperature in sintering. Thick film and ceramic sensors that between two kinds of processes have many mon characteristics, in some respects, you can think of ceramic art thick film technology is a variant. Each technology has its own strengths and weaknesses. Because of the research, development and production of a lower capital investment requirements, as well as the high stability of the sensor parameters and other reasons, the use of ceramics and thick film sensors more reasonable. 哈爾濱理工大學遠東學院學士學位論文 20 傳感器 /傳感器 傳感器是 一種物理設(shè)備或生物器官 ， 可以發(fā)現(xiàn) ， 外面的世界的信號 ， 自然條件 （ 例如光、熱、濕度 ） 或化學成分 （ 如吸煙 ）， 并找出信息給其他設(shè)備或器官。 王瑞老師 一絲不茍的作風 ，嚴謹求實的態(tài)度，踏踏實實的精神，不僅授我以文，而且教我做人，使人 終生受益無窮 。 測試結(jié)果表明，本系統(tǒng)實現(xiàn)了預期功能。按 “ 設(shè)置 ” 鍵及 “ 加 ”“ 減 ” 鍵將下限動作溫度值 TL設(shè)為 20攝氏度，將上限動作溫度值 TH設(shè)為 23攝氏度，用書對著 DS18B20煽動 ，顯示溫度逐漸降低，當達到 攝氏度時繼電器 1動作，將風扇關(guān)閉，第五位數(shù)碼管閃爍顯示 “ L” ，表示當 前溫度低于 TL值。 顯示驅(qū)動程序以查七段碼取得各數(shù)碼管應(yīng)顯數(shù)字，逐位掃描顯示。 每次設(shè)定的 TL、 TH值均拷備到 DS18B20的 EEROM內(nèi)，在單片機掉電后設(shè)定值不會丟失，在再次上電時從 DS18B20的 EEROM中讀回上次設(shè)定的上下限動作溫度值 TH、 TL，用戶 要實現(xiàn)根據(jù)當前溫度實時的控制風扇的狀態(tài)，需要在程序中不時的判斷當前溫度值是否超過設(shè)定的動作溫度值范圍，此部分功能由比較控制子程序 TEMP_COMP來完成。再按一次設(shè)置鍵 K3，進入高溫切換大風檔溫度值 TH設(shè)置狀態(tài)，此時按下 “ 加 ” 鍵 K1， TH值加一，長按 K1不放可實現(xiàn)快速加 1，按下 “ 減 ” 鍵 K2， TH值減 1，長按 K2不放可實現(xiàn)快速減 1。當檢測到傳感器工作正常后，發(fā)出溫度轉(zhuǎn)換命令及讀取溫度值命令，將從 DS18B20讀取的二進制溫度值轉(zhuǎn)換為七段碼在 LED上顯示出來。 該電路為無級調(diào)速電路，通過調(diào)節(jié)滑動變阻器的阻值來改變通過雙向二極管的電流，控制雙向晶閘管的導通角，從而控制電機的轉(zhuǎn)速。當按下 S1 時，可以加 1，長按可以快速加 1，當按下 S2 時，可以減 1， 長按可以快速減 1。 溫度設(shè)定主要是通過按鍵 S S2|、 S3 來設(shè)定的。要顯示的數(shù)據(jù)通過 P0 口送給數(shù)碼管顯示，通過 P2 口的 — 五個端口分別對數(shù)碼管進行位選，事實上數(shù)碼管是間斷被點亮的，只是其間斷時間十分短， 掃描周期在 20ms 以下， 利 用人眼視覺暫留， 我們 基本看不出它們的閃爍 。 圖 44 電源 哈爾濱理工大學遠東學院學士學位論文 9 數(shù)碼管顯示電