【正文】 摘 要 溫度是最重要的物理量之一，幾乎沒有什么物理特性不與溫度有關(guān)，電阻溫度測試儀是利用電阻隨溫度的變化而變化的物理特性而制成的。熱敏電阻具有穩(wěn)定性、耐氧化和價格便宜等特點 ,它在低溫測量中占有重要的地位。本文介紹了一種利用 8051單片機并采用熱敏電阻進行溫度測量的硬件電路以及軟件設(shè)計方法。利用電橋電路，將溫度的變化轉(zhuǎn)換成電壓的變化；利用恒流源和 8位 A/D轉(zhuǎn)換器設(shè)計溫度測量電路。被測溫度是通過軟件公式計算得到的。該方法具有簡單、實用、測量精度高、抗干擾能力強等特點。具有較高的性能價格比。熱敏電阻溫度測試儀 被應(yīng)用在很多方面，例如：電子溫度計、加熱恒溫電器、汽車電子溫度測控電路、醫(yī)療電子設(shè)備、充電電器等等。該熱敏電阻溫度測試儀具有很多優(yōu)點，例如：靈敏度高、體積小、熱慣性小、壽命長以及價格便宜等優(yōu)點。 關(guān)鍵詞 熱敏電阻；單片機；模數(shù)轉(zhuǎn)換器 Abstract The temperature is one of the most important physical parameters, almost all of the physical property associate with temperature. Thermal resistance temperature tester is using of resistance from physical property of changing in temperature. Thermally sensitive resistor is characterized by stability, antioxidation and cheap in price etc. It has important position in low temperature measurement. Introducing in this article is circuit hardware and software design that using 8051 singlechip microputer with thermally sensitive resistor for temperature measurement. The change of temperature is converted into change of voltage by using bridge circuit. The temperature measurement circuit is designed with constant current source and 8 bits A/D converter. Measurement of temperature is obtained through software program and formula calculation. This method has many characteristics such as simplicity, practicality, high precision of measure, strong antiinterference etc. And it has higher performancecost ratio. The thermally sensitive resistor temperature tester is applied to many areas such as electronic thermometers, thermostats heating appliances, automotive electronic temperature monitoring and control circuits, medical electronic equipment, rechargeable electrical appliances, etc. The thermally sensitive resistor temperature tester has many advantages such as high sensitivity, small size, small of the thermal inertia, longevity and cheap in price. Key words Thermally sensitive resistor。 Singlechip microputer。 A/D converter 目 錄 摘 要 ..............................................................................................................................................I Abstract.........................................................................................................................................II 第 1章 緒論 .................................................................................................................................1 課題研究的歷史背景 .......................................................................................................1 溫度測量方法的類型 .......................................................................................................2 溫度測量系統(tǒng)應(yīng)考慮的問題 ...........................................................................................2 數(shù)值溫度計研制的意義 ...................................................................................................3 本章小結(jié) ...........................................................................................................................3 第 2章 系統(tǒng)概述 .........................................................................................................................4 系統(tǒng)參數(shù)指標 ...................................................................................................................4 系統(tǒng)功能介紹 ...................................................................................................................4 本章小結(jié) ...........................................................................................................................4 第 3章 方案論證 .........................................................................................................................5 傳感器的選擇 ...................................................................................................................5 熱敏電阻的種類 .....................................................................................................5 熱敏電阻的主要參數(shù) .............................................................................................5 熱敏電阻的靈敏度 .................................................................................................6 熱敏電阻的優(yōu)點 .....................................................................................................7 熱敏 電阻的缺點 .....................................................................................................7 模數(shù)轉(zhuǎn)換器的選擇 ...........................................................................................................7 顯示電路的選擇 ...............................................................................................................8 本章小結(jié) ...........................................................................................................................8 第 4章 單片機硬件設(shè)計 .............................................................................................................9 總體思路和電路結(jié)構(gòu)框圖 ...............................................................................................9 電源電路的設(shè)計 ...............................................................................................................9 三端穩(wěn)壓管 7805....................................................................................................9 電源電路的設(shè)計 ...................................................................................................10 電容濾波電路 .......................................................................................................11 單片機模塊電路 .............................................................................................................11 系統(tǒng)的需求分析 ........................................................................................