【正文】 ............... 9 24秒倒計(jì)時(shí)電路 .............................................................................................. 10 12分鐘倒計(jì)時(shí)電路設(shè)計(jì) .....................................................................................11 譯碼器和顯示器的設(shè)計(jì) ................................................................................... 13 節(jié)次控制電路的設(shè)計(jì) ...................................................................................... 13 五 protues仿真與結(jié)果分析 ....................................................................................... 14 24秒倒計(jì)時(shí)仿真調(diào)試 ..................................................................................... 14 12分倒計(jì)時(shí)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(jì)圖 ............................................................................................................. 21 孔維維 比賽專(zhuān)用計(jì)時(shí)器設(shè)計(jì) 2 比賽專(zhuān)用計(jì)時(shí)器設(shè)計(jì) 孔維維 （ 甘肅農(nóng)業(yè)大學(xué)工學(xué)院農(nóng)電專(zhuān)業(yè)，甘肅蘭州， 730070） 摘要： 本設(shè)計(jì)為籃球比賽專(zhuān)用計(jì)時(shí)器，該設(shè)計(jì)是脈沖數(shù)字電路的簡(jiǎn)單應(yīng)用。本設(shè)計(jì)完成的中途計(jì)時(shí)功能，實(shí)現(xiàn)了在許多的特定場(chǎng)合進(jìn)行時(shí)間追蹤的功能，在社會(huì)生活中也具有廣泛的應(yīng)用價(jià)值。 關(guān)鍵詞 ： 74ls192 24秒倒計(jì)時(shí) 譯碼顯示電路 控制電路 報(bào)警電路 孔維維 比賽專(zhuān)用計(jì)時(shí)器設(shè)計(jì) 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(zhuān)用計(jì)時(shí)器設(shè)計(jì) 4 一 緒論 隨著科技發(fā)展，籃球計(jì)時(shí)器不僅應(yīng)用于 NBA， CBA 這樣專(zhuān)業(yè)的籃球賽場(chǎng)上，也廣泛應(yīng)用于民用的普通賽場(chǎng)上，方便于每場(chǎng)比賽的公平公正。 在當(dāng)今社會(huì)隨著物質(zhì)生活的提高，人們對(duì)精神文 化的需求也越來(lái)越高。 孔維維 比賽專(zhuān)用計(jì)時(shí)器設(shè)計(jì) 5 二 總體設(shè)計(jì)思路、基本原理和框圖 籃球比賽計(jì)時(shí)器的主要功能包括： 12 分鐘倒計(jì)時(shí)、進(jìn)攻方 24 秒倒計(jì)時(shí)計(jì)時(shí)暫停，重新開(kāi)啟和結(jié)束警報(bào)提示。當(dāng)比賽開(kāi)始時(shí)，倒計(jì)時(shí)從 12： 00開(kāi)始逐秒遞減到 00：00。 節(jié)數(shù)記次：四個(gè) LED 分別表示四場(chǎng)節(jié)次，根據(jù)比賽場(chǎng)次的轉(zhuǎn)換，用適當(dāng)?shù)姆椒ㄊ惯@四個(gè) LED 依次自動(dòng)指示四場(chǎng)節(jié)次。包括 12 分鐘和 24秒倒計(jì)時(shí)。 24秒計(jì)數(shù)芯片的置數(shù)端和 12 分的置數(shù)、清零端共用一個(gè)開(kāi)關(guān)，比賽開(kāi)始后， 24 秒的置數(shù)端也無(wú)效， 24 秒的倒