定时器设计毕业论文（含外文翻译）.doc

摘 要 在我国应用范围比较广泛的是机械式发条定时器,但在实际应用中所产生的问题比较多，走时不准，易停摆等问题严重影响定时器的质量。 本文在对机械式发条式定时器其缺点分析的基础上提出了基于数字电路技术的定时器设计方案。这个定时器电路比较简单，成本低，便于维修，省去了机械定时器每次必须扭动定时按钮的麻烦，对电器的全自动化很有利。由振荡器产生方波后经过分频器分别产生周期为的方波，分别用来减计数和加计数，这两种方波通过计数器后输出BCD码，BCD码通过发光二极管进行显示。 首先，根据设计要求，设计电路原理方框图，然后，通过对电路原理的分析，对电路元件进行选择并设定相应的电路图元件参数，最后，设计电路的接线图并对整个系统进行功能测试。 【关键词】定时器 发光二极管 定时周期 触发器 计数器 振荡 ABSTRACT In the broader scope of our application is a mechanical starting timer in the practical application of issues arising from the relatively more time to walk, stopped easily the timer problems seriously affect quality. The mechanical and starting a timer on the basis of the analysis of the shortcomings of technology-based digital timer circuit design. This timer electric circuit quite is simple, the cost is low, it is advantageous for the service , omitted the mechanical timer each time to have to sway from side to side fixed time the button trouble, was very advantageous to the electric appliance entire automation. Square-wave generated by the oscillator after a cycle frequency divider respectively square-wave for the cycle of 1 minute and 1 second respectively for minus count and increases count, both through the counter after square-wave export BCD code, BCD code through the light-emitting diode display. First, according to designs the request, designs the circuitry block diagram, then, through to the circuitry analysis, carries on the choice and the hypothesis corresponding electrograph part parameter to the circuit element, finally, designs the electric circuit the wiring diagram and carries on the function test to the overall system. 【Key word】Timer LED Cut-off relay Hold time Timing cycle Trigger Power outlet Boot time 目 录 前 言 - 1 - 第1章 绪 论 - 2 - 第一节 课题的来源和意义 - 2 - 第二节 电子定时器的应用 - 2 - 第三节 电子定时器的发展前景 - 2 - 第2章 逻辑电路的介绍 - 4 - 第一节 数字电路的特点 - 4 - 第二节 基本逻辑电路 - 4 - 第三节 CMOS集成电路的应用 - 4 - 一、 常用特性 - 5 - 二、CMOS门电路的应用 - 5 - 第3章 各集成电路的功能及原理 - 7 - 第一节 CD4017的功能及原理 - 7 - 一、 CD4017引脚图 - 7 - 二