说明：  本系统由单片机AT89C52、温度检测电路、A/D转换电路、键盘显示电路等部分组成，其原理框图如图2.1所示。在系统中，利用传感器测得电阻炉实际温度并转换成毫伏级电压信号，该电压信号经过温度检测放大电路和A/D转换电路转换成与炉温相对应的数字信号进入单片机，单片机进行数据处理后，通过液晶显示器显示温度，并判断是否报警，同时将温度与设定温度比较，由设定的控制算法计算出控制量，根据控制量通过控制固态继电器的导通和关闭时间从而控制电阻丝的导通时间，以实现对炉温的控制。
(Resistance furnace is applied extensively in industry production.The control result oftemperature control system will directly affect quality of products and efficiency of production so the exact precision is demanded. At present conventional PID control method is used usually by most domestic resistance furnace in industries. The temperature control for resistance furnace has many characteristics such as non-linearity, big inertia,great lag. It is difficult to establish its accurate mathematic model so we can t obtain the satisfied result using the conventional PID control method.Therefore, it is very valuable to design the temperature control system which has exact precision and steady operation.)