【正文】 ...................................................................................................... 4 ..................................................................................................... 4 ....................................................................................... 4 二 總體設(shè)計思路、基本原理和框圖 ................................................................................. 5 ............................................................................................................ 5 ............................................................................................................ 5 ..................................................................................................... 6 三主要硬件簡介 ............................................................................................................... 7 ............................................................................................................... 7 cd4511 ............................................................................................................. 8 四 單元電路設(shè)計 ............................................................................................................. 9 ........................................................................................... 9 24秒倒計時電路 .............................................................................................. 10 12分鐘倒計時電路設(shè)計 .....................................................................................11 譯碼器和顯示器的設(shè)計 ................................................................................... 13 節(jié)次控制電路的設(shè)計 ...................................................................................... 13 五 protues仿真與結(jié)果分析 ....................................................................................... 14 24秒倒計時仿真調(diào)試 ..................................................................................... 14 12分倒計時仿真調(diào)試 ..................................................................................... 14 節(jié)次電路仿真 調(diào)試 .......................................................................................... 15 結(jié)果分析 ........................................................................................................ 15 六 總結(jié) ........................................................................................................................ 17 參考文獻(xiàn) ........................................................................................................................ 18 致謝 ............................................................................................................................... 19 附錄一元件清單 ............................................................................................................. 20 附錄二總設(shè)計圖 ............................................................................................................. 21 孔維維 比賽專用計時器設(shè)計 2 比賽專用計時器設(shè)計 孔維維 （ 甘肅農(nóng)業(yè)大學(xué)工學(xué)院農(nóng)電專業(yè)，甘肅蘭州， 730070） 摘要： 本設(shè)計為籃球比賽專用計時器，該設(shè)計是脈沖數(shù)字電路的簡單應(yīng)用。 關(guān)鍵詞 ： 74ls192 24秒倒計時 譯碼顯示電路 控制電路 報警電路 孔維維 比賽專用計時器設(shè)計 3 Special timer design. KONGWeiwei （ Major in agricultural electrification and automation in the College of engineering institute of Gansu Agriculture University， Gansu Lanzhou， 730070） Abstract: The design for the basketball game timer, the design is a simple application of the pulse digital circuit. This timer functionuous, asn is plete, can be directly cleared, start, pause and conti well as with the alarm function, while the use of seven digital tube to display time. This timer has a start, pause and continuous function, can easily achieve the breakpoint timer function, when the timer is reduced to zero, the alarm signal will be issued. The pletion of the design of the timing function, to achieve a number of specific occasions to track the function of time,in social life also has a wide range of applica