目录摘要.................................................................0第1章引言..........................................................11.1设计概述..........................................................11.2设计目标与意义....................................................11.3章节安排..........................................................2第2章方案论证与选型..................................................42.1设计任务分析......................................................42.2方案论证与选择....................................................52.2.1方案一........................................................52.2.2方案二........................................................62.2.3方案三........................................................62.2.4方案四........................................................72.3方案确定..........................................................7第3章电路设计........................................................83.1原理分析..........................................................83.2抢答器电路总体框图................................................83.3抢答电路分析介绍..................................................93.3.1编码部分.....................................................103.3.2锁存部分.....................................................123.3.3译码显示部分.................................................143.3.4控制部分.....................................................163.4定时电路分析介绍.................................................183.4.1脉冲部分.....................................................193.4.2减计时部分...................................................223.5报警电路分析介绍.................................................233.5.1报警控制部分.................................................243.5.2蜂鸣器报警部分...............................................273.6总原理图.........................................................28第4章产品调试.......................................................294.1调试的设备.......................................................294.2调试步骤..................................