摘要无论在农业、工业、科学研究等领域，温度测量应用广泛，涉及到许多方面。根据使用环境和精确度的不同要求，所设计出的温度计外观形状功能也不尽相同。本文设计的数字温度计是以铂热电阻Pt100为测温装置，TC7117CPL芯片为A/D转换核心，四个数码管显示，能显示-20℃到100℃的温度范围。设计中运用差分放大电路有效消除共模电压，同时将温度信号转换为电压信号输出，通过运算放大器放大信号，使其与温度呈线性变化，接着经过A/D转换器将模拟信号转化为数字信号，最后通过LED数码管显示。设计过程中运用到模拟电路和数字电路的知识，使用最新最通用的电路仿真软件cadence/OrCADPSpice 16.6进行模拟部分的仿真验证，并在Altium Designer 6中绘制PCB原理图和线路板图。本文设计的温度计读数方便，测温范围广，测温较准确，其输出温度采用数字显示。63610

毕业论文关键词  数字温度计 Pt100铂热电阻  PSpiceA/D转化     LED数码管显示

毕业设计说明书（论文）外文摘要

Title Design of the Digital Thermometer Based on Thermocouple

Abstract Whether in agriculture, industry, science and other fields, temperature measurement is widely used, involves many aspects. According to the environment and accuracy of the different requirements, the designs of the exterior shape of the thermometer functions are not the same. This article uses Pt100 platinum resistance as the temperature measuring device, and uses TC7117CPL chip as A / D converter core, uses four digital tubes to display,which can display -20 ℃ to 100 ℃. Design of effective elimination of the use of differential amplification circuit common-mode voltage, while the temperature signal is converted to a voltage signal output by the operational amplifier amplifies the signal, it changes linearly with temperature, and then through the A / D converter converts the analog signal into a digital signal and finally through the LED digital display. Design process applied to the analog circuits and digital circuits knowledge to use the latest and most versatile circuit simulation software cadence OrCADPSpice 16.6 for the analog portion of simulation and Altium Designer 6 draw PCB schematic and board. This design of the thermometer can be easy read, and the temperature range is large, the accuracy is well also. The output of the temperature is displayed by digital tubes.

Keywords Digital thermometer Pt100 platinum resistance PSpice A / D conversion  LED digital tube display

目次

1 绪论 1

1.1 研究的背景与意义 1

1.2 国内外研究现状 2

1.3 论文章节安排 3

2 设计方案的设定 3

2.1 恒定电流源传感器 4

2.2 输入部分的设计 6

2.3 数字/模拟转换 9

2.4 数字显示电路 11

3 原理图仿真及印刷电路板开发 11

3.1 原理图绘制 11

3.2 Pspice仿真及参数分析 14

3.3印刷电路的开发