數字頻率計畢業設計論文

電子機電論文編號:JD032    字數:9620,頁數:28

目  錄

摘要 I
Abstract..................................................................II
1  緒論................................................................... 1
1.1  數字頻率計的發展現狀及研究概況....................................... 1
1.2  本課題研究背景及主要研究意義......................................... 1
1.3  本課題主要研究內容 ...................................................2
1.4  本章小結............................................................. 2
2  數字頻率計的設計....................................................... 3
2.1  主要技術要求..........................................................3
2.2  方案論證............................................................. 4
2.3  電路設計............................................................. 4
2.3.1  電路工作原理簡述 ...................................................5
2.3.2  部分芯片功能介紹 ...................................................5
2.3.2.1  CD4026簡介 .......................................................6
2.3.2.2  NE556簡介 ........................................................7
2.3.2.3  CD4007簡介....................................................... 7
2.3.2.4  MC4583B簡介.......................................................8
2.3.2.5  七段LED顯示器件.................................................. 8
2.3.3  單元電路結構設計 ...................................................8
2.3.3.1  電源電路設計 .....................................................10
2.3.3.2  時基信號產生電路的設計 ...........................................13
2.3.3.3  信號處理電路設計 .................................................14
2.3.3.4  顯示電路的設計................................................... 15
2.3.3.5  脈沖整寬電路的設計 ...............................................15
2.4  本章小結 .............................................................16
3  電路調試............................................................... 17
3.1  單元電路調試 .........................................................18
3.2  系統連調............................................................. 20
4  結論 ...................................................................23
致謝 ......................................................................25
參考文獻.................................................................. 26
附錄...................................................................... 27

摘要
在數字電路中，數字頻率計屬于時序電路，它主要由具有記憶功能的觸發器構成。在計算機及各種數字儀表中，都得到了廣泛的應用。在CMOS電路系列產品中，數字頻率計是用量最大、品種很多的產品，是計算機、通訊設備、音頻視頻等科研生產領域不可缺少的測量儀器，并且與許多電參量的測量方案、測量結果都有十分密切的關系，因此，頻率的測量就顯得更為重要。
本課題主要選擇以集成芯片作為核心器件，設計了一個簡易數字頻率計，以觸發器和計數器為核心，由信號輸入、隔直，觸發、計數、數據處理和數據顯示等功能模塊組成。放大整型電路：對被測信號進行預處理；閘門電路：由NE556構成一個秒信號，攫取單位時間內進入計數器的脈沖個數；時基信號：產生一個秒信號；計數器譯碼電路：計數譯碼集成在一塊芯片上，計單位時間內脈沖個數，把十進制計數器計數結果譯成BCD碼；顯示：把BCD碼譯碼在數碼管顯示出來。設計中采用了模塊化設計方法，采用適當的放大和整形，提高了測量頻率的范圍。
關鍵詞：頻率，集成電路，譯碼電路，計數電路，雙穩態觸發器

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.