数字频率计毕业设计论文

电子机电论文编号:JD032    字数:9620,页数:28

目  录

摘要 I
Abstract..................................................................II
1  绪论................................................................... 1
1.1  数字频率计的发展现状及研究概况....................................... 1
1.2  本课题研究背景及主要研究意义......................................... 1
1.3  本课题主要研究内容 ...................................................2
1.4  本章小结............................................................. 2
2  数字频率计的设计....................................................... 3
2.1  主要技术要求..........................................................3
2.2  方案论证............................................................. 4
2.3  电路设计............................................................. 4
2.3.1  电路工作原理简述 ...................................................5
2.3.2  部分芯片功能介绍 ...................................................5
2.3.2.1  CD4026简介 .......................................................6
2.3.2.2  NE556简介 ........................................................7
2.3.2.3  CD4007简介....................................................... 7
2.3.2.4  MC4583B简介.......................................................8
2.3.2.5  七段LED显示器件.................................................. 8
2.3.3  单元电路结构设计 ...................................................8
2.3.3.1  电源电路设计 .....................................................10
2.3.3.2  时基信号产生电路的设计 ...........................................13
2.3.3.3  信号处理电路设计 .................................................14
2.3.3.4  显示电路的设计................................................... 15
2.3.3.5  脉冲整宽电路的设计 ...............................................15
2.4  本章小结 .............................................................16
3  电路调试............................................................... 17
3.1  单元电路调试 .........................................................18
3.2  系统连调............................................................. 20
4  结论 ...................................................................23
致谢 ......................................................................25
参考文献.................................................................. 26
附录...................................................................... 27

摘要
在数字电路中，数字频率计属于时序电路，它主要由具有记忆功能的触发器构成。在计算机及各种数字仪表中，都得到了广泛的应用。在CMOS电路系列产品中，数字频率计是用量最大、品种很多的产品，是计算机、通讯设备、音频视频等科研生产领域不可缺少的测量仪器，并且与许多电参量的测量方案、测量结果都有十分密切的关系，因此，频率的测量就显得更为重要。
本课题主要选择以集成芯片作为核心器件，设计了一个简易数字频率计，以触发器和计数器为核心，由信号输入、隔直，触发、计数、数据处理和数据显示等功能模块组成。放大整型电路：对被测信号进行预处理；闸门电路：由NE556构成一个秒信号，攫取单位时间内进入计数器的脉冲个数；时基信号：产生一个秒信号；计数器译码电路：计数译码集成在一块芯片上，计单位时间内脉冲个数，把十进制计数器计数结果译成BCD码；显示：把BCD码译码在数码管显示出来。设计中采用了模块化设计方法，采用适当的放大和整形，提高了测量频率的范围。
关键词：频率，集成电路，译码电路，计数电路，双稳态触发器

Digital frequency meter design
Student: Ke Xiao-yun   Teacher: Wang Yong-jie
Abstract: In the digital circuit, the digital cymometer is the circuit of time sequence, it is mainly formed by trigger with memory function. In the computer and various digital instruments, it is widely used . Among CMOS circuit serial products, cymometer consumption most heavy, variety a lot of product. The digital cymometer is a measuring instrument in scientific research such as computer , communication apparatus , audio and video with indispensable production field, and the measurement scheme with a lot of electric parameters , result of measuring all have a very close relation, so, the measurement of frequency seems even more important.
   This subject has mainly explained that chooses integrated circuit as the key device, has designed a simple and easy digital cymometer, regard trigger and counter as core , input , separate by signal frank , touch off , count circuit , data processing , data reveal module of function make up. Enlarge the circuit of integrated type: To be carried on the preconditioning by the signal of examining; The circuit of the gate : Formed a second signal by NE556, seize the pulse number of entering the counter in unit time; The base signal of hour: Produce the signal for one second; The decipher circuit of the counter : Count deciphers and integrate on the chip together, count the pulse number in unit time, count the result of the decimal counter to translate into BCD yard; Reveal : In charge of revealing BCD one yard of deciphers in the number . Design adopt module design method, adopt appropriate enlarge and whole, have improved frequency of designing.
Keywords: frequency，Integrated circuit，Translate the coding electric circuit，Count the electric circuit，Dual Schmitt Trigger.