【正文】 ............... 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 ........................................................................................................................ 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)大學工學院農(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)字電路的簡單應用。本設(shè)計完成的中途計時功能，實現(xiàn)了在許多的特定場合進行時間追蹤的功能，在社會生活中也具有廣泛的應用價值。 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 application value. The circuit consists of five modules: a second pulse generator, a counter,a decoding display circuit, a control circuit and an alarm circuit. Control circuit directly control counter start count, pause / continuous counting, decoding display circuit display and other functions. When the of reset control circuit when the switch is closed, in the digital tube display number 24. Whenever a seconds pulse signal input to the counter, digital tube digital will automatically reduce the 1, decreasing to zero when the timer, an alarm circuit, a photoelectric alarm signal and the buzz. Key words: 74LS192 24 seconds countdown decoding display circuit control circuit alarm circuit 孔維維 比賽專用計時器設(shè)計 4 一 緒論 隨著科技發(fā)展，籃球計時器不僅應用于 NBA， CBA 這樣專業(yè)的籃球賽場上，也廣泛應用于民用的普通賽場上，方便于每場比賽的公平公正。 在當今社會隨著物質(zhì)生活的提高，人們對精神文 化的需求也越來越高。 孔維維 比賽專用計時器設(shè)計 5 二 總體設(shè)計思路、基本原理和框圖 籃球比賽計時器的主要功能包括： 12 分鐘倒計時、進攻方 24 秒倒計時計時暫停，重新開啟和結(jié)束警報提示。當比賽開始時，倒計時從 12： 00開始逐秒遞減到 00：00。 節(jié)數(shù)記次：四個 LED 分別表示四場節(jié)次，根據(jù)比賽場次的轉(zhuǎn)換，用適當?shù)姆椒ㄊ惯@四個 LED 依次自動指示四場節(jié)次。包括 12 分鐘和 24秒倒計時。 24秒計數(shù)芯片的置數(shù)端和 12 分的置數(shù)、清零端共用一個開關(guān)，比賽開始后， 24 秒的置數(shù)端也無效， 24 秒的倒