流水灯课程设计.doc

河南理工大学电子技术课程设计报告心形流水灯姓名:明*学号:**专业班级:电气10-7班指导老师:李端所在学院:电气工程与自动化学院、目录摘要··························································3一、设计指标(要求)··········································4二、系统框图·················································4三、各单元电路设计、······························································································································································································································11四、电路图及工作原理········································12五、元器件清单···············································12六、实际PCB图或布线········································13七、············································································14八、参考文献·················································15摘要随着时代的进步,人们审美方式的提高,流水灯在都市生活中扮演着愈加不可或缺的角色。酒店,婚庆,酒吧,KTV,广场,商场,招牌等场所的流星雨灯条、流水瀑布灯、月花灯等,给人以繁星闪耀,流水似瀑的感觉。而彩色LED闹钟,手机外壳的跑马灯的应用点缀了我们的日常生活。流水灯的控制方法可通过多种方法实现,但相对现代可编程控制器而言,利用移位寄存器实现最为便利。通常用左移寄存器实现灯的单方向移动,通过双向移位寄存器实现灯的双向移动。此次课程设计,是通过制作四路流水灯来实现18个LED心形灯的控制。关键词:双向移位寄存器,NE555脉冲电路,LED灯。设计指标(1)输出为4路(18个)LED灯;(2)要求能实现左移右移功能,左右移自动切换;(3)移动速度可调节(4)每个循环左移和右移的步数和变化规律自定。二、系统框图三、,为整个电路提供所需的时钟信号CP。(1)NE555内部结构555定时器是一种模拟电路和数字电路相结合的中规模集成电路,其内部结构如图(A)及管脚排列如图(B)所示。它由分压器、比较器、基本R--S触发器和放电三极管等部分组成。分压器由三个5的等值电阻串联而成。分压器为比较器、提供参考电压,比较器的参考电压为,加在同相输入端,比较器的参考电压为,加在反相输入端。比较器由两个结构相同的集成运放、组成。高电平触发信号加在的反相输入端,与同相输入端的参考电压比较后,其结果作为基本R--S触发器端的输入信号;低电平触发信号加在的同相输入端,与反相输入端的参考电压比较后,其结果作为基本R—S触发器端的输入信号。基本R--S触发器的输出状态受比较器、的输出端控制。(2)NE555构成的多谐振荡器工作原理由555定时器组成的多谐振荡器如图(C)所示,其中R1、R2和电容C为外接元件。其工作波如图(D)所示。设电容的初始电压=0,t=0时接通电源,由于电容电压不能突变,所以高、低触发端==0<VCC,比较器A1输出为高电平,A2输出为低电平,即,(1表示高电位,0表示低电位),触发器置1,定时器输出此时,定时器内部放电三极管截止,电源经,向电容C充电,逐渐升高。当上升到时,输出由0翻转为1,这时,触发顺保持状态不变。所以0<t<期间,定时器输出为高电平1。时刻,上升到,比较器的输出由1变为0,这时,,触发器复0,定时器输出。期间,,放电三极管T导通,电容C通过放电。按指数规律下降,当时比较器输出由0变为1,R-S触发器的,Q的状态不变,的状态仍为低电平。时刻,下降到,比较器输出由1变为0,R---S触发器的1,0,触发器处于1,定时器输出。此时电源再次向电容C放电,重复上述过程。通过上述分析可知,