文档介绍：哈尔滨理工大学
毕业设计
题目: 基于热电偶的控温器设计
院系: 电气与电子工程学院
2013年 6 月 21 日
基于热电偶的控温器设计
摘要
热电偶(thermocouple)是温度测量仪表中常用的测温元件,它直接测量温度,并把温度信号转换成热电动势信号。各种热电偶的外形常因需要而极不相同,但是它们的基本结构却大致相同,通常由热电极、绝缘套保护管和接线盒等主要部分组成。
本文研究开发的抗干扰热电偶控温器,从电路设计、PCB电路板布局布线、到软件设计等方面,对热电偶工作的干扰信号进行滤波处理,使这一热电偶控温器能够在复杂的电磁环境下稳定、可靠地工作。
为了达到提高测温精度的目的,需要对热电偶进行冷端补偿,以弥补热电偶冷端处于室温环境时造成的误差;在PCB电路设计中,从电源、电缆、印制板三个层次对热电偶控温器进行抗干扰设计;在软件设计过程中,利用数字滤波技术进一步对干扰信号滤波处理、并用线性插值法求解温度值,最后用模糊算法实现控温器对环境温度的控制。
关键词热电偶;冷端补偿;控温器;抗干扰
A Design of Thermocouple Based Temperature Controller
Abstract
Thermocouple (thermocouple) is monly used temperature sensor temperature measurement instrument, It measure the temperature directly, and the temperature signal is converted into the thermal electromotive force shape of the thermocouple is not the same because the different needs. but their basic structure are roughly the same, and pose of a hot electrode, insulating sleeve tube protector and the junction box and other main parts .
This research is about the research of an anti-disturbed temperature controller with thermocouple as its thermal order to make the temperature controller work stably and reliably in plicated ic environment,different methods are used in the design methods cover different stages of the design,including the design of the hardware circuit,the layout of the printed circuit board(PCB),and the software design.
In the design of the hardware circuit,in order to improve the accuracy of the temperature controller,it’s necessary to do some work on the cold the thermocouple is usually work with its cold junction in the room temperature rather than in the standard of 0℃.In the PCB design stage,three design hierarchies are used to make the temperature controller immune to the disturbance of the ic environment,these hierarchies include:powersupply,electric cable,and the printed circuit the software design,the digital filter is used to finally filter the disturb signal,and the