多路温度测控系统的设计

目的利用单片机技术设计多路温度测控系统，实现多路温度的测量和控制．方法系统以单片机AT89C52为核心，利用多路转换器和新型数字器件MAX6675构成8路K型热电偶温度测量电路，利用D／A转换器AD7528和驱动电路构成输出电路，实现8路一一对应的闭环温度测量控制．系统软件采用PID控制器．结果实践证明，可根据需要增减系统温度信号采样通道的数目，使用软件抗干扰措施，提高了采样数据的可靠性．简化了输入输出硬件结构，使系统具有低成本高速度和较好的测量控制精度．结论多路温度测控系统作为整机适用于现场测量控制应用，也可作为多路温度控制模块应用在体积小、温度测量精度要求较高的大型系统中．

Design of Multi-channel Temperature-measuring and Controlling System

In order to realize the measurement and controlling of multi-channel temperature,multi-channel temperature-measuring and controlling system was designed by single-chip technology.In this system,in order to realize the complete correspondence closed-circle control of eight channel temperature,regarding single-chip AT89C52 as the core,the eight channel temperature samples of type-K thermocouple are made up of analog multiplexers and Cold-Junction-Compensated K-Thermocouple-to-Digital Converter and the output-circuit is made up of D/A,AD7528,and driver-circuit.The software is made up of PID algorithm.The results indicate that the system can increase or decrease the sample access number of system temperature sign according to the need,at the same time,adopts anti-interaction measure in order to realize better reliability. This system has simple structure of hardware,high speed of control and enough accuracy in practice.This system can be used as field device to realize measure and control of temperature and it can also be used as multi-channel temperature control module in the large system which needs small volume and better accuracy of temperature measurement.