【正文】 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 I 數(shù)字式競(jìng)賽搶答器 摘要 本設(shè)計(jì)按照設(shè)計(jì)任務(wù)，根據(jù)數(shù)字邏輯電路的一般設(shè)計(jì)步驟和各單元的邏輯功能，選擇合適的器件，設(shè)計(jì)出了符合設(shè)計(jì)要求的系統(tǒng)電路。 數(shù)字 式競(jìng)賽 搶答器 主要 由主體電路與擴(kuò)展電路組成 ， 優(yōu)先編碼電路、鎖存器、譯碼電路將參賽隊(duì)的輸入信號(hào)在顯示器上輸出 ； 用控制電路和主持人開(kāi)關(guān)啟動(dòng)報(bào)警電路，以上兩部分組成主體電路。通過(guò)定時(shí)電路和譯碼電路將秒脈沖產(chǎn)生的信號(hào)在顯示器上輸出實(shí)現(xiàn)計(jì)時(shí)功能，構(gòu)成擴(kuò)展電路。 該搶答器功能全面， 具有鎖存與顯示功能。即選手按動(dòng)按鈕，鎖存相應(yīng)的編號(hào)，并在 LED 數(shù)碼管上顯示，同時(shí)揚(yáng)聲器發(fā)出報(bào)警聲響 提示 ， 同時(shí)還要封鎖電路以防其他選手再搶答 ， 優(yōu)先搶答選手的編號(hào)一直保持到主持人將系統(tǒng)清除為止。 搶答器具有定時(shí)搶答功能，且一次搶答的時(shí)間由主持人設(shè)定， 參賽選手在設(shè)定的時(shí)間內(nèi)進(jìn)行搶答，搶答有效，定時(shí)器停止工作 ， 顯示器上顯示選手的編號(hào)和搶答的時(shí)間，并保持到主持人將系統(tǒng)清除為止 ； 如果定時(shí)時(shí)間已到，無(wú)人搶答，本次搶答無(wú)效，系統(tǒng)報(bào)警并禁止搶答 。完成電路設(shè)計(jì)后，再 經(jīng)過(guò)布線(xiàn)、焊接、調(diào)試等工作后數(shù)字搶答器成形。 關(guān)鍵詞 搶答器；時(shí)序控制；定時(shí)電路；報(bào)警電路 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 II Answer browser digital race Abstract According to the design mission, choose suitable ponents according to the general design step of the numerical logic electric circuit and the logic function of each unit, design to meet the system electric circuit of the design request. The numerical type contest robs the answer machine mainly from the corpus electric circuit with expand electric circuit to constitute, having the initiative to code electric circuit, lock to save a machine and translating the code electric circuit will take part in a game the importation signal of the brigade to output on the display。 Report to the police electric circuit with the control electric circuit and questionmaster switch start, the above two parts constitute corpus electric circuit. Pass in fixed time electric circuit and translate the code electric circuit second signal with output pulse at display up output a realization to account function, constitute to expand electric circuit. The rob the answer machine function pletely, have a lock to save a nd show function. It is to say the contestant presses a button, to lock and save relevant serial numbers, and displayed on the LED digital tube, the loudspeaker will send out the hint of the warning sound loudly at the same time, still need to block the electric circuit in the meantime in order to prevent the other contestants rob again, the serial number of the contestant who rob the answer first will be keep up till the system have been clear up by the questionmaster. Rob the answer tool has function of robbing answer in fixed time, and once rob time of the answer is set by the questionmaster, the contestants rob an answer in the enactment of time, the timer will stop working when robbing an answer effectively, the serial number of the contestant and rob time will be displayed on the display, and will be kept on till the system has been cleared up by the 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 III questionmaster。 If the fixed time has already arrived, no man robs, this time robbing an answer invalid, the system warns and forbid to rob an answer. Pass by wiring, welding, and adjusting the digital rob an answer machine is pleted after the design of the electric circ Keywords rob an answer machine。 the cycle time control。 rob answer electric circuit。 in fixed time electric circuit。 warning electric circuit 哈爾濱理工大學(xué)遠(yuǎn)東學(xué)院學(xué)士學(xué)位論文 IV 目錄 摘要 .......................................................................................................................I Abstract ............................................................................................................... II 第 1 章 緒論 ........................................................................................................ 1 第 2 章 總體方案設(shè)計(jì) ........................................................................................ 2 設(shè)計(jì)內(nèi)容與要求 ....................................................................................... 2 數(shù)字搶答器總體方框圖 ........................................................................... 2 本章小結(jié) ................................................................................................... 2 第 3 章 單元電路的設(shè)計(jì)及參數(shù)計(jì)算 ................................................................ 4 單元電路的設(shè)計(jì) ....................................................................................... 4 搶答器電路 ........................................................................................ 4 定時(shí)電路 ............................................................................................ 4 報(bào)警電路 ............................................................................................ 6 時(shí)序控制電路 .................................................................................... 7 參數(shù)計(jì)算 ................................................................................................... 8 二極管閃爍及間隔時(shí)間計(jì)算 ............................................................ 8 報(bào)警發(fā)生時(shí)間 的計(jì)算 ........................................................................ 9 總體電路圖 ............................................................................................... 9 本章小結(jié) ................................................................................................... 9 第 4 章 元器件的功能和作用 .......................................................................... 10 555 定時(shí)器 .............................................................................................. 10 555 定時(shí)器內(nèi)部結(jié)構(gòu) ........................................................................ 10 定 時(shí) 器 原 理 .................................................................................................................... 10 同步十進(jìn)制可逆計(jì)數(shù)器 74LS192 ......................................................... 11 8 線(xiàn) 3 線(xiàn) 優(yōu)先編碼器 74LS148 ............................................................. 12 譯碼器 74LS48 ....................................................................................... 13 數(shù)碼顯示譯碼器 ..................................................................................... 15 單 穩(wěn)態(tài)觸發(fā)器 74121 .............................................................................. 16 單穩(wěn)態(tài)觸發(fā)器 74121 的工作原理