温度自动控制系统
本科生毕业设计（论文）I摘 要孵化场的孵化温度直接影响着孵蛋率和幼雏的健康，目前孵化的温度控制还依靠人工，简单的水银温度计作为孵化温度测量的常规手段，很容易出现控温不及时，不准确。针对这个实际情况，本文设计了一套温度自动控制系统。系统设计内容包括输入通道设计、输出控制电路设计、单片机最小系统设计、软件设计和调试。输入通道采用热敏电阻传感器对孵化场温度进行三路检测，将检测结果通过多路模拟开关 CD4051 进行切换，把三个通路的模拟量分时接通并送入 A/D 转换器 AD574；输出控制电路以光电耦合器 MOC3041 对双向可控硅（TLC336A）进行触发进而对加热器控制；单片机最小系统设计包括单片机型号选择、外部数据存储器静态 RAM6264 扩展、LED 显示电路、键盘的接口电路、时钟电路和复位电路设计；软件有主程序、显示子程序、加热报警子程序、PID算法程序和数据采集程序等。本系统的硬件电路结构简单、系统的可靠性高，温度控制精度可达 0.1。关键词：单片机；传感器；自动控制；PID 算法 本科生毕业设计（论文）IIAbstractThe temperature of hatchery directly affects the rate of hatching and the chick health. At present the temperature being controlled depends upon man-power, taking the simple mercury thermometer as the conventional method. It is possible to appear not prompt and plate out of true to control. In view of this actual situation, this paper designs temperatures automatic control system.Content of system design include input channel design, output control circuit design, and the minimum system of single chip microcomputer circuit design, software design and debugging. The design of input channel adopts the thermistor sensor to detect the temperature of hatchery on three road, switching the result through the multichannel analog switch CD4051, and then sends the simulations of three thoroughfares into the A/D converting machine AD574. The output control circuit triggers (TLC336A) the bidirectional silicon-controlled rectifier by photoelectricity coupler MOC3041 to control the heating devices；A system design of single chip microcomputer includes a model choice, the data memory static state RAM6264 of the exterior data expands, LED display electric circuit and keyboard connection circuit, clock and reset circuit; The software design contain main program, the sub- program, of display, the sub- program of heating and warning, the program of PID algorithm, the program of data acquiring.The hardware electric circuit structure of this system is simple. The system is reliable. The temperature of accuracy can reach 0.1.Key words: Single chip microcomputer；Sensor；Automatic control；PID algorithm本科生毕业设计（论文）III目 录第 1 章 绪 论.11.1 计算机控制系统简介.11.2 课题来源.21.3 主要设计内容.31.4 设计思路.3第 2 章 系统硬件设计.42.1 89C-51 单片机简介.42.2 数据存储器扩展.42.3 传感器.62.3.1 传感器的选择.62.3.2 热敏电阻的特点.62.3.3 温度检测电路设计.72.4 A/D 转换电路.92.4.1 多路开关的选择.92.4.2 AD574 结构及原理.112.4.3 AD574 与单片机接口电路设计.132.5 显示接口电路设计.142.5.1 显示技术的发展及其特点.142.5.2 LED 显示接口设计.142.6 输出控制电路设计.162.6.1 输出控制电路元件简介.172.6.2 输出控制电路的设计.202.7 简易式键盘接口电路设计.222.7.1 8255 可编程并行 I/O 接口设计.222.7.2 键盘电路及其说明.232.8 复位电路.252.9 时钟电路.262.10 报警电路.26第 3 章 系统软件设计.28本科生毕业设计（论文）IV3.1 主程序设计.
