摘 要

本篇毕业设计主要是为了设计一个水温控制器，需要用29V的电源去控制整个电路，使10至20毫升的水可以保持在一个大致的恒定温度，水温控制器是一个在生活中随处可见的物品，最常见的莫过于饮水机了，当然，饮水机需要预测水温并且控制水温在一个温度范围，而本文设计的水温控制器却需要控制在正负一摄氏度之间，降低了对精确性的要求。不止是饮水机，恒温箱这种设计在生活其他各各领域也有涉及，化学、医学以及所有要求精确控制温度的地方都会需要这种设计。控制方法本文是用c52单片机进行对整个电路的控制，首先是由温度检测器测出水温，然后将水温变换为数字信号传给单片机。另外键盘也会把输入的预设温度数字信号传输给单片机，单片机就会将这俩个信号进行比较，判断出谁大谁小，如果预设温度高于温度检测器检测的温度，单片机就会控制加热片开始工作，直至比预设温度大，此时单片机就会控制加热片关闭，由加热片的余温继续加热。此时水温就会继续上升一段时间，然后就会下降了，当水温低于预设温度时，单片机又会控制加热片重新开始工作，使温度再次上升，如此一直循环下去。并且在这个系统运行的整个过程中，会有一个四位数码管随时显示此时水中的温度。软件被我分成了一个主程序和一个子程序，先是寻衅主程序，在主程序运行达到一定条件后就会进入到子程序，在子程序达到一定条件后，又会跳回主程序，如此反复循环。
按照这个整体思路，我设计好了电路图，并且增加了一个存储芯片，并且给单片机编辑了程序，开关键盘部分也设计了相关功能，使键盘可以为整个系统输入一个预设温度。但是在烧录的过程中出现了许多问题，程序经常会出错，这个时候就需要一直修改，直到整个系统的功能可以正常运行，画图软件我使用的是AD10，电路图由这个软件制作出来还是比较容易的，当软件编程和电路图部分全部完成后，我就开始购买材料自己动手制作了，焊接电路板也只用对着电路图焊接就行，但是在完成后的实验阶段，发现如果仅仅和预设温度做比较，就会经常超出1摄氏度的范围，于是我就修改了程序，使水中温度低于预设温度0.5摄氏度时就开始关闭加热，重新开启的温度需要比预设温度低0.6摄氏度，这样修改了之后实验数据就可以接受了，使精度保持在一摄氏度之内。

关键词：水温控制器；恒定温度；单片机；c52编程

Abstract

This graduation design is mainly for the design of a temperature controller, need to use 29V to control the power supply circuit, the 10 to 20 ml of water can be maintained at a roughly constant temperature, the temperature controller is a ubiquitous in life items, the most common way to drinking machine, of course water temperature prediction, and control the temperature in a temperature range to drinking water machine, water temperature controller designed in this paper is the need to control between positive and negative one degree Celsius, reduces the accuracy requirements. Not only the water fountain and the thermostat, but also in all other areas of life, chemistry, medicine, and all places requiring precise temperature control will require this design. Control method is to use C52 microcontroller to control the whole circuit. Firstly, the temperature is measured by the temperature detector, then the water temperature is changed into digital signal and transmitted to the microcontroller. In addition the keyboard will be to enter the preset temperature digital signal transmission to the microcontroller, the microcontroller will compare the two signals, determining who is large or small, if the temperature is higher than the preset temperature detected by the temperature detector, the microcontroller will control the heating plate began to work until now than the preset temperature, the microcontroller will control the heater off continue heating by Yu heating tablets. The temperature will continue to rise for a period of time, and then decreased, when the water temperature is lower than the preset temperature, microcontroller will control the heating plate began to work again, make the temperature rise again, so the cycle continues. And in the whole process of the operation of the system, there will be a four bit digital tube at any time to show the temperature of the water. My software is divided into a main program and a subroutine, the first is a main program, the main program running to reach certain conditions will enter into the subroutine, subroutine in certain conditions, and jump back to the main program, so repeatedly.

According to the overall thinking, I designed the circuit diagram, and added a memory chip, and edit the program to the microcontroller, switch keyboard design related functions, the keyboard can be input to a preset temperature for the entire system. But in the burning process of the emergence of many problems, often go wrong, this time on the need to have been modified until the function of the whole system can run normally, I use AD10 drawing software, this software produced by the circuit is relatively easy, when software programming and circuit part is completed, I begin to buy material DIY, welding circuit board only to circuit diagram of welding line, but in the experimental stage is completed, and found only if the preset temperature is compared, will always exceed 1 degrees Celsius, so I have to modify the program, so that the water temperature is lower than the preset temperature is 0.5 degrees Celsius start off heating, re opening temperature of 0.6 degrees Celsius lower than the preset temperature, so that changes after experimental data will be accepted, so fine Degrees are kept within one degree celsius.

Key Words：Water temperature controller box；Constant temperature; single chip microcomputer; C52 programming

目录

第1章 绪论 1

1.1 设计目的及意义 1

1.2 国内外现状 2
第2章 水温控制系统设计 4

2.1 设计要求 4

2.2 设计指标 4

2.3 设计总体思路 4
2.3.1 加热电路 4
2.3.2 控制电路 5
第3章 硬件设计 6

3.1 主要电路硬件 6
3.1.1 加热片 6
3.1.2 三极管 6
3.1.3 继电器 8

3.2 控制电路硬件 9
3.2.1 控制器 9

3.2.2 显示器 12

3.2.3 键盘部分 13
3.2.4 温度传感器 14

第4章 软件部分 15

4.1 控制思路 15

4.2 控制流程 15

4.2.1 主程序流程 15

4.2.2 子程序流程 17

参考文献 18

附录一 21

附录二 21