【正文】 哈爾濱理工大學遠東學院學士學位論文 I 數(shù)字式競賽搶答器 摘要 本設計按照設計任務，根據(jù)數(shù)字邏輯電路的一般設計步驟和各單元的邏輯功能，選擇合適的器件，設計出了符合設計要求的系統(tǒng)電路。 數(shù)字 式競賽 搶答器 主要 由主體電路與擴展電路組成 ， 優(yōu)先編碼電路、鎖存器、譯碼電路將參賽隊的輸入信號在顯示器上輸出 ； 用控制電路和主持人開關啟動報警電路，以上兩部分組成主體電路。通過定時電路和譯碼電路將秒脈沖產(chǎn)生的信號在顯示器上輸出實現(xiàn)計時功能，構成擴展電路。 該搶答器功能全面， 具有鎖存與顯示功能。即選手按動按鈕，鎖存相應的編號，并在 LED 數(shù)碼管上顯示，同時揚聲器發(fā)出報警聲響 提示 ， 同時還要封鎖電路以防其他選手再搶答 ， 優(yōu)先搶答選手的編號一直保持到主持人將系統(tǒng)清除為止。 搶答器具有定時搶答功能，且一次搶答的時間由主持人設定， 參賽選手在設定的時間內(nèi)進行搶答，搶答有效，定時器停止工作 ， 顯示器上顯示選手的編號和搶答的時間，并保持到主持人將系統(tǒng)清除為止 ； 如果定時時間已到，無人搶答，本次搶答無效，系統(tǒng)報警并禁止搶答 。完成電路設計后，再 經(jīng)過布線、焊接、調(diào)試等工作后數(shù)字搶答器成形。 關鍵詞 搶答器；時序控制；定時電路；報警電路 哈爾濱理工大學遠東學院學士學位論文 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 哈爾濱理工大學遠東學院學士學位論文 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 哈爾濱理工大學遠東學院學士學位論文 IV 目錄 摘要 .......................................................................................................................I Abstract ............................................................................................................... II 第 1 章 緒論 ........................................................................................................ 1 第 2 章 總體方案設計 ........................................................................................ 2 設計內(nèi)容與要求 ....................................................................................... 2 數(shù)字搶答器總體方框圖 ........................................................................... 2 本章小結 ................................................................................................... 2 第 3 章 單元電路的設計及參數(shù)計算 ................................................................ 4 單元電路的設計 ....................................................................................... 4 搶答器電路 ........................................................................................ 4 定時電路 ............................................................................................ 4 報警電路 ............................................................................................ 6 時序控制電路 .................................................................................... 7 參數(shù)計算 ................................................................................................... 8 二極管閃爍及間隔時間計算 ............................................................ 8 報警發(fā)生時間 的計算 ........................................................................ 9 總體電路圖 ............................................................................................... 9 本章小結 ................................................................................................... 9 第 4 章 元器件的功能和作用 .......................................................................... 10 555 定時器 .............................................................................................. 10 555 定時器內(nèi)部結構 ........................................................................ 10 定 時 器 原 理 .................................................................................................................... 10 同步十進制可逆計數(shù)器 74LS192 ......................................................... 11 8 線 3 線 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