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目录
1 绪 论.........................................................................................................................................................1
1.1 选题依据及研究意义 ........................................................................................................................1
1.2 超声波的概述 ....................................................................................................................................2
1.2.1 超声波的相关概念 .....................................................................................................................2
1.2.2 超声波的研究发展和应用 .........................................................................................................2
1.3 流量计概述 ........................................................................................................................................3
1.3.1 流量的定义 .................................................................................................................................3
1.3.2 超声波流量计的原理与分类 .....................................................................................................3
1.3.3 流量的测量仪器 .........................................................................................................................6
1.3.4 流量计的发展现状 .....................................................................................................................7
1.4 本设计的设计目标及研究内容 ........................................................................................................8
2 超声波流量计的总体设计 ......................................................................................................................9
2.1 传感器概述及其特性 ........................................................................................................................9
2.2 超声波换能器概述 ............................................................................................................................9
2.2.1 超声波换能器能量转换原理 .....................................................................................................9
2.2.2 超声波换能器的简介及主要性能指标....................................................................................10
2.3 超声波换能器的选择及设计 ..........................................................................................................11
2.3.1 超声波换能器的主要参数 .......................................................................................................11
2.3.2 超声波换能器的安装方式及选择............................................................................................12
2.4 流量计总体设计框图 ......................................................................................................................13
3 超声波流量计硬件设计 .........................................................................................................................14
3.1 单片机系统 ......................................................................................................................................14
3.1.1 单片机的选择 ...........................................................................................................................14
3.1.2 AT89S51 单片机简介................................................................................................................15
3.2 显示电路的设计 ..............................................................................................................................17
3.2.1 LED 显示器的结构和原理........................................................................................................17
3.2.2 共阴极 LED 结构及显示原理..................................................................................................18
3.3 按键调节电路的设计 ......................................................................................................................19