目录一、试验简介..........................................................................................................................11.1 试验目旳：.................................................................................................................11.2 试验内容：.................................................................................................................11.3 试验需求：.................................................................................................................1二、设计简介..........................................................................................................................22.1 设计概况：.................................................................................................................22.2 设计规定.....................................................................................................................2三、设计原理..........................................................................................................................33.1 整体电路设计原理：.................................................................................................33.2 分步电路设计原理：.................................................................................................43.2.1 秒信号发生电路..............................................................................................43.2.2 计时电路..........................................................................................................63.2.3 清零电路..........................................................................................................83.2.4 译码显示电路................................................................................................103.2.5 总体电路连接图............................................................................................10四、 电路安装与调试阐明......................................................................................
