1.1 采用纯硬件的闭环控制系统.....................................2
1.2 采用单片机与高精度传感器结合的方式...........................2
2 电路分析 ..........................................................3
2.1 单片机选择...................................................3
2.1.1 AT89C51 单片机特性 .....................................3
2.1.2 AT89C51 单片机管脚 .....................................3
2.2 压力传感器选择 ..............................................4
2.2.1 AK-1C-2................................................4
2.2.2 AK-1C-2 主要技术指标 ...................................5
2.2.3 AK-1C-2 电气连接 .......................................5
2.2.4 AK-1C-2 外形 ...........................................6
2.3 温度传感器 ..................................................6
2.3.1 K 型热电偶 .............................................6
2.3.2 K 型热电偶测温原理 .....................................7
2.3.3 K 型热电偶的元件配合使用 ...............................8
2.3.4 K 型热电偶与 MAX6675 连接 ...............................9
2.4.放大电路 ....................................................9
2.4.1 电路放大倍数 ..........................................10
2.4.2 放大电路 ..............................................10
2.5 A/D 转换电路................................................10
2.5.1 ADC0809 主要特性 ......................................10
2.5.2 ADC0809 内部逻辑结构..................................10
2.5.3 ADC0809 引脚结构......................................11
2.5.4 ADC0809 各脚功能......................................11
2.5.5 ADC0809 输入模拟量要求................................12
2.5.6 ADC0809 通道选择表 ....................................12
2.5.7 ADC0809 应用说明......................................13
2.5.8 地址锁存器 74ls373.....................................13
2.5.9 引脚功能 ..............................................13
2.5.10 ADC0809 连接图 .......................................14
2.6 数码管显示及电路............................................14
2.6.1 八位七段数码管外形....................................15
2.6.2 MAX7221 介绍 ..........................................15
2.7 按键及其电路................................................17
2.7.1 独立式非编码键盘接口 ..................................18
2.8 报警电路....................................................18
2.9 电源........................................................19
3 单片机程序.......................................................20
3.1 汇编语言....................................................20
3.2 C 语言......................................................20
3.2.1 基本特性 ..............................................20
3.3 温度报警系统................................................21
3.4 压力报警系统................................................22
结论...............................................................23
